Import wiredtiger: 1be1b793becdfb5f4b2ae950449aa3710ca320ce from branch mongodb-4.2

ref: 3334609975..1be1b793be
for: 4.1.2

WT-3276       Add recover=salvage to recover from a corrupted log file
WT-3943       Include full error message when a python test asserts
WT-3955       Add verbose option to log more messages on error returns
WT-4160       Restore performance when timestamps are not in use
WT-4168       Update upgrading documentation for 3.1.0 release
WT-4169       Fix wt verify dump-pages failure
WT-4171       Enabling tree walk timing stress causes excessive slowdown
WT-4172       Add diagnostic hazard pointer checks in more places before freeing refs
WT-4174       Do not access the lookaside file in rollback_to_stable when running with in_memory=true
WT-4178       Fixes for wt_btree_immediately_durable needed for in-memory
WT-4179       Expose WiredTiger crc32c functions
WT-4182       Use conservative approach for log checksum errors
WT-4188       Coverity: unchecked return value complaints

80 files changed, 1120 insertions, 553 deletions

diff --git a/src/third_party/wiredtiger/NEWS b/src/third_party/wiredtiger/NEWS
index 7bf3b0e7edb..1e821835386 100644
--- a/src/third_party/wiredtiger/NEWS
+++ b/src/third_party/wiredtiger/NEWS
@@ -1,6 +1,14 @@
 Ticket reference tags refer to tickets in the MongoDB JIRA tracking system:
 https://jira.mongodb.org
 
+WiredTiger release 3.1.0, 2018-07-12
+------------------------------------
+
+See the upgrading documentation for details of API and behavior changes.
+
+See JIRA changelog for a full listing:
+https://jira.mongodb.org/projects/WT/versions/19708
+
 WiredTiger release 3.0.0, 2018-01-08
 ------------------------------------
 
diff --git a/src/third_party/wiredtiger/README b/src/third_party/wiredtiger/README
index f21ff213a7c..fd8757621bf 100644
--- a/src/third_party/wiredtiger/README
+++ b/src/third_party/wiredtiger/README
@@ -1,6 +1,6 @@
-WiredTiger 3.1.0: (April 23, 2018)
+WiredTiger 3.1.1: (July 12, 2018)
 
-This is version 3.1.0 of WiredTiger.
+This is version 3.1.1 of WiredTiger.
 
 WiredTiger release packages and documentation can be found at:
 
@@ -8,7 +8,7 @@ WiredTiger release packages and documentation can be found at:
 
 The documentation for this specific release can be found at:
 
-	http://source.wiredtiger.com/3.1.0/index.html
+	http://source.wiredtiger.com/3.1.1/index.html
 
 The WiredTiger source code can be found at:
 
diff --git a/src/third_party/wiredtiger/RELEASE_INFO b/src/third_party/wiredtiger/RELEASE_INFO
index ee25ecd6c56..2014ba3ee74 100644
--- a/src/third_party/wiredtiger/RELEASE_INFO
+++ b/src/third_party/wiredtiger/RELEASE_INFO
@@ -1,6 +1,6 @@
 WIREDTIGER_VERSION_MAJOR=3
 WIREDTIGER_VERSION_MINOR=1
-WIREDTIGER_VERSION_PATCH=0
+WIREDTIGER_VERSION_PATCH=1
 WIREDTIGER_VERSION="$WIREDTIGER_VERSION_MAJOR.$WIREDTIGER_VERSION_MINOR.$WIREDTIGER_VERSION_PATCH"
 
 WIREDTIGER_RELEASE_DATE=`date "+%B %e, %Y"`
diff --git a/src/third_party/wiredtiger/build_posix/aclocal/options.m4 b/src/third_party/wiredtiger/build_posix/aclocal/options.m4
index 7d0df5d65ac..9d07958bad9 100644
--- a/src/third_party/wiredtiger/build_posix/aclocal/options.m4
+++ b/src/third_party/wiredtiger/build_posix/aclocal/options.m4
@@ -53,19 +53,6 @@ AM_CONDITIONAL([HAVE_BUILTIN_EXTENSION_ZSTD],
     [test "$wt_cv_with_builtin_extension_zstd" = "yes"])
 AC_MSG_RESULT($with_builtins)
 
-AH_TEMPLATE(
-    HAVE_CRC32_HARDWARE, [Define to 1 to configure CRC32 hardware support.])
-AC_MSG_CHECKING(if --enable-crc32-hardware option specified)
-AC_ARG_ENABLE(crc32-hardware,
-	AS_HELP_STRING([--enable-crc32-hardware],
-	    [Enable CRC32 hardware support.]), r=$enableval, r=yes)
-case "$r" in
-no)	wt_cv_enable_crc32_hardware=no;;
-*)	AC_DEFINE(HAVE_CRC32_HARDWARE)
-	wt_cv_enable_crc32_hardware=yes;;
-esac
-AC_MSG_RESULT($wt_cv_enable_crc32_hardware)
-
 AH_TEMPLATE(HAVE_DIAGNOSTIC, [Define to 1 for diagnostic tests.])
 AC_MSG_CHECKING(if --enable-diagnostic option specified)
 AC_ARG_ENABLE(diagnostic,
diff --git a/src/third_party/wiredtiger/build_posix/aclocal/version-set.m4 b/src/third_party/wiredtiger/build_posix/aclocal/version-set.m4
index 3f87f7f6507..8b39a5d09d6 100644
--- a/src/third_party/wiredtiger/build_posix/aclocal/version-set.m4
+++ b/src/third_party/wiredtiger/build_posix/aclocal/version-set.m4
@@ -2,8 +2,8 @@ dnl build by dist/s_version
 
 VERSION_MAJOR=3
 VERSION_MINOR=1
-VERSION_PATCH=0
-VERSION_STRING='"WiredTiger 3.1.0: (April 23, 2018)"'
+VERSION_PATCH=1
+VERSION_STRING='"WiredTiger 3.1.1: (July 12, 2018)"'
 
 AC_SUBST(VERSION_MAJOR)
 AC_SUBST(VERSION_MINOR)
diff --git a/src/third_party/wiredtiger/build_win/wiredtiger.def b/src/third_party/wiredtiger/build_win/wiredtiger.def
index 3ee9f6b6a9d..79fa84a11e0 100644
--- a/src/third_party/wiredtiger/build_win/wiredtiger.def
+++ b/src/third_party/wiredtiger/build_win/wiredtiger.def
@@ -1,8 +1,8 @@
 LIBRARY WIREDTIGER
 EXPORTS
-    wiredtiger_checksum_crc32c
     wiredtiger_config_parser_open
     wiredtiger_config_validate
+    wiredtiger_crc32c_func
     wiredtiger_open
     wiredtiger_pack_close
     wiredtiger_pack_int
diff --git a/src/third_party/wiredtiger/build_win/wiredtiger_config.h b/src/third_party/wiredtiger/build_win/wiredtiger_config.h
index 55431f59fae..bb4cc7848f8 100644
--- a/src/third_party/wiredtiger/build_win/wiredtiger_config.h
+++ b/src/third_party/wiredtiger/build_win/wiredtiger_config.h
@@ -25,9 +25,6 @@
 /* Define to 1 if you have the `clock_gettime' function. */
 /* #undef HAVE_CLOCK_GETTIME */
 
-/* Define to 1 to enable CRC32 hardware support. */
-/* #undef HAVE_CRC32_HARDWARE */
-
 /* Define to 1 for diagnostic tests. */
 /* #undef HAVE_DIAGNOSTIC */
 
diff --git a/src/third_party/wiredtiger/dist/api_data.py b/src/third_party/wiredtiger/dist/api_data.py
index d29e9655fb3..e96a147fc70 100644
--- a/src/third_party/wiredtiger/dist/api_data.py
+++ b/src/third_party/wiredtiger/dist/api_data.py
@@ -590,8 +590,7 @@ connection_runtime_config = [
         type='list', undoc=True,
         choices=[
         'checkpoint_slow', 'lookaside_sweep_race', 'split_1', 'split_2',
-        'split_3', 'split_4', 'split_5', 'split_6', 'split_7', 'split_8',
-        'split_9']),
+        'split_3', 'split_4', 'split_5', 'split_6', 'split_7', 'split_8']),
     Config('verbose', '', r'''
         enable messages for various events. Options are given as a
         list, such as <code>"verbose=[evictserver,read]"</code>''',
@@ -601,6 +600,7 @@ connection_runtime_config = [
             'checkpoint',
             'checkpoint_progress',
             'compact',
+            'error_returns',
             'evict',
             'evict_stuck',
             'evictserver',
@@ -709,7 +709,7 @@ wiredtiger_open_log_configuration = [
         Config('recover', 'on', r'''
             run recovery or error if recovery needs to run after an
             unclean shutdown''',
-            choices=['error','on'])
+            choices=['error', 'on', 'salvage'])
     ]),
 ]
 
diff --git a/src/third_party/wiredtiger/dist/s_export.list b/src/third_party/wiredtiger/dist/s_export.list
index 72ce553ac9b..e49fa113d96 100644
--- a/src/third_party/wiredtiger/dist/s_export.list
+++ b/src/third_party/wiredtiger/dist/s_export.list
@@ -1,7 +1,7 @@
 # List of OK external symbols.
-wiredtiger_checksum_crc32c
 wiredtiger_config_parser_open
 wiredtiger_config_validate
+wiredtiger_crc32c_func
 wiredtiger_open
 wiredtiger_pack_close
 wiredtiger_pack_int
diff --git a/src/third_party/wiredtiger/dist/s_funcs.list b/src/third_party/wiredtiger/dist/s_funcs.list
index eed29e91fc1..95c568a19ff 100644
--- a/src/third_party/wiredtiger/dist/s_funcs.list
+++ b/src/third_party/wiredtiger/dist/s_funcs.list
@@ -33,7 +33,6 @@ __wt_stat_join_aggregate
 __wt_stat_join_clear_all
 __wt_stream_set_no_buffer
 __wt_try_readlock
-wiredtiger_checksum_crc32c
 wiredtiger_config_parser_open
 wiredtiger_config_validate
 wiredtiger_pack_int
diff --git a/src/third_party/wiredtiger/dist/s_string.ok b/src/third_party/wiredtiger/dist/s_string.ok
index 64b9758877e..215f1c36e8b 100644
--- a/src/third_party/wiredtiger/dist/s_string.ok
+++ b/src/third_party/wiredtiger/dist/s_string.ok
@@ -207,8 +207,8 @@ LLLLLLL
 LOGREC
 LOGSCAN
 LOOKASIDE
+LRSVv
 LRU
-LRVv
 LSB
 LSM
 LSN
diff --git a/src/third_party/wiredtiger/dist/s_void b/src/third_party/wiredtiger/dist/s_void
index 9c5f6711da0..f97b910620f 100755
--- a/src/third_party/wiredtiger/dist/s_void
+++ b/src/third_party/wiredtiger/dist/s_void
@@ -55,6 +55,8 @@ func_ok()
 	    -e '/int __wt_block_compact_start$/d' \
 	    -e '/int __wt_block_manager_size$/d' \
 	    -e '/int __wt_block_write_size$/d' \
+	    -e '/int __wt_buf_catfmt$/d' \
+	    -e '/int __wt_buf_fmt$/d' \
 	    -e '/int __wt_curjoin_joined$/d' \
 	    -e '/int __wt_cursor_close$/d' \
 	    -e '/int __wt_cursor_noop$/d' \
@@ -65,6 +67,7 @@ func_ok()
 	    -e '/int __wt_once$/d' \
 	    -e '/int __wt_posix_directory_list_free$/d' \
 	    -e '/int __wt_session_breakpoint$/d' \
+	    -e '/int __wt_set_return_func$/d' \
 	    -e '/int __wt_spin_init$/d' \
 	    -e '/int __wt_spin_trylock$/d' \
 	    -e '/int __wt_stat_connection_desc$/d' \
diff --git a/src/third_party/wiredtiger/examples/c/ex_all.c b/src/third_party/wiredtiger/examples/c/ex_all.c
index 139f39fe673..190c2c421d3 100644
--- a/src/third_party/wiredtiger/examples/c/ex_all.c
+++ b/src/third_party/wiredtiger/examples/c/ex_all.c
@@ -1356,8 +1356,9 @@ main(int argc, char *argv[])
 	const char *buffer = "some string";
 	size_t len = strlen(buffer);
 	/*! [Checksum a buffer] */
-	uint32_t crc32c;
-	crc32c = wiredtiger_checksum_crc32c(buffer, len);
+	uint32_t crc32c, (*func)(const void *, size_t);
+	func = wiredtiger_crc32c_func();
+	crc32c = func(buffer, len);
 	/*! [Checksum a buffer] */
 	(void)crc32c;
 	}
diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index ea08c6eb2d1..3392241798d 100644
--- a/src/third_party/wiredtiger/import.data
+++ b/src/third_party/wiredtiger/import.data
@@ -1,5 +1,5 @@
 {
-    "commit": "333460997573558235254cb7e84dad765bb844a7", 
+    "commit": "1be1b793becdfb5f4b2ae950449aa3710ca320ce", 
     "github": "wiredtiger/wiredtiger.git", 
     "vendor": "wiredtiger", 
     "branch": "mongodb-4.2"
diff --git a/src/third_party/wiredtiger/src/async/async_api.c b/src/third_party/wiredtiger/src/async/async_api.c
index db755db198a..cb3cd8986f3 100644
--- a/src/third_party/wiredtiger/src/async/async_api.c
+++ b/src/third_party/wiredtiger/src/async/async_api.c
@@ -145,7 +145,7 @@ retry:
 	 */
 	if (op == NULL || op->state != WT_ASYNCOP_FREE) {
 		WT_STAT_CONN_INCR(session, async_full);
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 	}
 	/*
 	 * Set the state of this op handle as READY for the user to use.
diff --git a/src/third_party/wiredtiger/src/btree/bt_debug.c b/src/third_party/wiredtiger/src/btree/bt_debug.c
index 16e25c1fe25..d18e3887ca5 100644
--- a/src/third_party/wiredtiger/src/btree/bt_debug.c
+++ b/src/third_party/wiredtiger/src/btree/bt_debug.c
@@ -53,7 +53,7 @@ static int __debug_ref(WT_DBG *, WT_REF *);
 static int __debug_row_skip(WT_DBG *, WT_INSERT_HEAD *);
 static int __debug_tree(WT_SESSION_IMPL *, WT_REF *, const char *, uint32_t);
 static int __debug_update(WT_DBG *, WT_UPDATE *, bool);
-static int __dmsg_wrapup(WT_DBG *);
+static int __debug_wrapup(WT_DBG *);
 
 /*
  * __wt_debug_set_verbose --
@@ -270,7 +270,7 @@ __debug_config(WT_SESSION_IMPL *session, WT_DBG *ds, const char *ofile)
 		ds->f = __dmsg_event;
 	} else {
 		if ((ds->fp = fopen(ofile, "w")) == NULL)
-			return (EIO);
+			return (__wt_set_return(session, EIO));
 		__wt_stream_set_line_buffer(ds->fp);
 		ds->f = __dmsg_file;
 	}
@@ -282,12 +282,13 @@ __debug_config(WT_SESSION_IMPL *session, WT_DBG *ds, const char *ofile)
 }
 
 /*
- * __dmsg_wrapup --
+ * __debug_wrapup --
  *	Flush any remaining output, release resources.
  */
 static int
-__dmsg_wrapup(WT_DBG *ds)
+__debug_wrapup(WT_DBG *ds)
 {
+	WT_DECL_RET;
 	WT_ITEM *msg;
 	WT_SESSION_IMPL *session;
 
@@ -303,7 +304,7 @@ __dmsg_wrapup(WT_DBG *ds)
 	 */
 	if (msg != NULL) {
 		if (msg->size != 0)
-			WT_RET(__wt_msg(session, "%s", (char *)msg->mem));
+			ret = __wt_msg(session, "%s", (char *)msg->mem);
 		__wt_scr_free(session, &ds->msg);
 	}
 
@@ -311,7 +312,7 @@ __dmsg_wrapup(WT_DBG *ds)
 	if (ds->fp != NULL)
 		(void)fclose(ds->fp);
 
-	return (0);
+	return (ret);
 }
 
 /*
@@ -435,59 +436,61 @@ __wt_debug_disk(
     WT_SESSION_IMPL *session, const WT_PAGE_HEADER *dsk, const char *ofile)
 {
 	WT_DBG *ds, _ds;
+	WT_DECL_RET;
 
 	ds = &_ds;
 	WT_RET(__debug_config(session, ds, ofile));
 
-	WT_RET(ds->f(ds, "%s page", __wt_page_type_string(dsk->type)));
+	WT_ERR(ds->f(ds, "%s page", __wt_page_type_string(dsk->type)));
 	switch (dsk->type) {
 	case WT_PAGE_BLOCK_MANAGER:
 		break;
 	case WT_PAGE_COL_FIX:
 	case WT_PAGE_COL_INT:
 	case WT_PAGE_COL_VAR:
-		WT_RET(ds->f(ds, ", recno %" PRIu64, dsk->recno));
+		WT_ERR(ds->f(ds, ", recno %" PRIu64, dsk->recno));
 		/* FALLTHROUGH */
 	case WT_PAGE_ROW_INT:
 	case WT_PAGE_ROW_LEAF:
-		WT_RET(ds->f(ds, ", entries %" PRIu32, dsk->u.entries));
+		WT_ERR(ds->f(ds, ", entries %" PRIu32, dsk->u.entries));
 		break;
 	case WT_PAGE_OVFL:
-		WT_RET(ds->f(ds, ", datalen %" PRIu32, dsk->u.datalen));
+		WT_ERR(ds->f(ds, ", datalen %" PRIu32, dsk->u.datalen));
 		break;
-	WT_ILLEGAL_VALUE(session);
+	WT_ILLEGAL_VALUE_ERR(session);
 	}
 
 	if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
-		WT_RET(ds->f(ds, ", compressed"));
+		WT_ERR(ds->f(ds, ", compressed"));
 	if (F_ISSET(dsk, WT_PAGE_ENCRYPTED))
-		WT_RET(ds->f(ds, ", encrypted"));
+		WT_ERR(ds->f(ds, ", encrypted"));
 	if (F_ISSET(dsk, WT_PAGE_EMPTY_V_ALL))
-		WT_RET(ds->f(ds, ", empty-all"));
+		WT_ERR(ds->f(ds, ", empty-all"));
 	if (F_ISSET(dsk, WT_PAGE_EMPTY_V_NONE))
-		WT_RET(ds->f(ds, ", empty-none"));
+		WT_ERR(ds->f(ds, ", empty-none"));
 	if (F_ISSET(dsk, WT_PAGE_LAS_UPDATE))
-		WT_RET(ds->f(ds, ", LAS-update"));
+		WT_ERR(ds->f(ds, ", LAS-update"));
 
-	WT_RET(ds->f(ds, ", generation %" PRIu64 "\n", dsk->write_gen));
+	WT_ERR(ds->f(ds, ", generation %" PRIu64 "\n", dsk->write_gen));
 
 	switch (dsk->type) {
 	case WT_PAGE_BLOCK_MANAGER:
 		break;
 	case WT_PAGE_COL_FIX:
-		WT_RET(__debug_dsk_col_fix(ds, dsk));
+		WT_ERR(__debug_dsk_col_fix(ds, dsk));
 		break;
 	case WT_PAGE_COL_INT:
 	case WT_PAGE_COL_VAR:
 	case WT_PAGE_ROW_INT:
 	case WT_PAGE_ROW_LEAF:
-		WT_RET(__debug_dsk_cell(ds, dsk));
+		WT_ERR(__debug_dsk_cell(ds, dsk));
 		break;
 	default:
 		break;
 	}
 
-	return (__dmsg_wrapup(ds));
+err:	WT_TRET(__debug_wrapup(ds));
+	return (ret);
 }
 
 /*
@@ -620,9 +623,9 @@ __wt_debug_tree_shape(
 
 	WT_WITH_PAGE_INDEX(session,
 	    ret = __debug_tree_shape_worker(ds, page, 1));
-	WT_RET(ret);
 
-	return (__dmsg_wrapup(ds));
+	WT_TRET(__debug_wrapup(ds));
+	return (ret);
 }
 
 /* AUTOMATIC FLAG VALUE GENERATION START */
@@ -705,7 +708,7 @@ __wt_debug_page(
 	WT_WITH_BTREE(session, btree,
 	    ret = __debug_page(ds, ref, WT_DEBUG_TREE_LEAF));
 
-	WT_TRET(__dmsg_wrapup(ds));
+	WT_TRET(__debug_wrapup(ds));
 	return (ret);
 }
 
@@ -744,7 +747,7 @@ __debug_tree(
 
 	ret = __debug_page(ds, ref, flags);
 
-	WT_TRET(__dmsg_wrapup(ds));
+	WT_TRET(__debug_wrapup(ds));
 	return (ret);
 }
 
diff --git a/src/third_party/wiredtiger/src/btree/bt_discard.c b/src/third_party/wiredtiger/src/btree/bt_discard.c
index d31f76f629c..0d49adc19ca 100644
--- a/src/third_party/wiredtiger/src/btree/bt_discard.c
+++ b/src/third_party/wiredtiger/src/btree/bt_discard.c
@@ -32,29 +32,14 @@ __wt_ref_out(WT_SESSION_IMPL *session, WT_REF *ref)
 	 */
 	WT_ASSERT(session, S2BT(session)->evict_ref != ref);
 
-#ifdef HAVE_DIAGNOSTIC
-	{
-	WT_HAZARD *hp;
-	int i;
 	/*
 	 * Make sure no other thread has a hazard pointer on the page we are
 	 * about to discard.  This is complicated by the fact that readers
 	 * publish their hazard pointer before re-checking the page state, so
 	 * our check can race with readers without indicating a real problem.
-	 * Wait for up to a second for hazard pointers to be cleared.
+	 * If we find a hazard pointer, wait for it to be cleared.
 	 */
-	for (hp = NULL, i = 0; i < 100; i++) {
-		if ((hp = __wt_hazard_check(session, ref)) == NULL)
-			break;
-		__wt_sleep(0, 10000);
-	}
-	if (hp != NULL)
-		__wt_errx(session,
-		    "discarded page has hazard pointer: (%p: %s, line %d)",
-		    (void *)hp->ref, hp->file, hp->line);
-	WT_ASSERT(session, hp == NULL);
-	}
-#endif
+	WT_ASSERT(session, __wt_hazard_check_assert(session, ref, true));
 
 	__wt_page_out(session, &ref->page);
 }
@@ -263,6 +248,9 @@ __wt_free_ref(
 	if (ref == NULL)
 		return;
 
+	/* Assert there are no hazard pointers. */
+	WT_ASSERT(session, __wt_hazard_check_assert(session, ref, false));
+
 	/*
 	 * Optionally free the referenced pages.  (The path to free referenced
 	 * page is used for error cleanup, no instantiated and then discarded
diff --git a/src/third_party/wiredtiger/src/btree/bt_handle.c b/src/third_party/wiredtiger/src/btree/bt_handle.c
index 9160ff1dd21..613a95f321b 100644
--- a/src/third_party/wiredtiger/src/btree/bt_handle.c
+++ b/src/third_party/wiredtiger/src/btree/bt_handle.c
@@ -915,10 +915,11 @@ __wt_btree_immediately_durable(WT_SESSION_IMPL *session)
 
 	/*
 	 * This is used to determine whether timestamp updates should
-	 * be rolled back for this btree. It's likely that the particular
-	 * test required here will change when rollback to stable is
-	 * supported with in-memory configurations.
+	 * be rolled back for this btree. With in-memory, the logging
+	 * setting on tables is still important and when enabled they
+	 * should be considered "durable".
 	 */
-	return (FLD_ISSET(S2C(session)->log_flags, WT_CONN_LOG_ENABLED) &&
+	return ((FLD_ISSET(S2C(session)->log_flags, WT_CONN_LOG_ENABLED) ||
+	    (F_ISSET(S2C(session), WT_CONN_IN_MEMORY))) &&
 	    !F_ISSET(btree, WT_BTREE_NO_LOGGING));
 }
diff --git a/src/third_party/wiredtiger/src/btree/bt_slvg.c b/src/third_party/wiredtiger/src/btree/bt_slvg.c
index 54f4eaa8f52..411c7ed7cfe 100644
--- a/src/third_party/wiredtiger/src/btree/bt_slvg.c
+++ b/src/third_party/wiredtiger/src/btree/bt_slvg.c
@@ -2350,7 +2350,7 @@ __slvg_ovfl_ref(WT_SESSION_IMPL *session, WT_TRACK *trk, bool multi_panic)
 {
 	if (F_ISSET(trk, WT_TRACK_OVFL_REFD)) {
 		if (!multi_panic)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		WT_PANIC_RET(session, EINVAL,
 		    "overflow record unexpectedly referenced multiple times "
 		    "during leaf page merge");
diff --git a/src/third_party/wiredtiger/src/btree/bt_split.c b/src/third_party/wiredtiger/src/btree/bt_split.c
index a98de6c6c9f..2a69ef84540 100644
--- a/src/third_party/wiredtiger/src/btree/bt_split.c
+++ b/src/third_party/wiredtiger/src/btree/bt_split.c
@@ -449,7 +449,7 @@ __split_root(WT_SESSION_IMPL *session, WT_PAGE *root)
 	children = pindex->entries / btree->split_deepen_per_child;
 	if (children < 10) {
 		if (pindex->entries < 100)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		children = 10;
 	}
 	chunk = pindex->entries / children;
@@ -872,6 +872,8 @@ __split_parent(WT_SESSION_IMPL *session, WT_REF *ref, WT_REF **ref_new,
 		/* Free the backing block and address. */
 		WT_TRET(__wt_ref_block_free(session, next_ref));
 
+		WT_ASSERT(session,
+		    __wt_hazard_check_assert(session, next_ref, false));
 		WT_TRET(__split_safe_free(
 		    session, split_gen, exclusive, next_ref, sizeof(WT_REF)));
 		parent_decr += sizeof(WT_REF);
@@ -915,7 +917,7 @@ err:	__wt_scr_free(session, &scr);
 		 * being deleted, but don't be noisy, there's nothing wrong.
 		 */
 		if (empty_parent)
-			ret = EBUSY;
+			ret = __wt_set_return(session, EBUSY);
 		break;
 	case WT_ERR_PANIC:
 		__wt_err(session, ret, "fatal error during parent page split");
@@ -982,7 +984,7 @@ __split_internal(WT_SESSION_IMPL *session, WT_PAGE *parent, WT_PAGE *page)
 	children = pindex->entries / btree->split_deepen_per_child;
 	if (children < 10) {
 		if (pindex->entries < 100)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		children = 10;
 	}
 	chunk = pindex->entries / children;
@@ -1214,7 +1216,7 @@ __split_internal_lock(
 	 * the parent, give up to avoid that deadlock.
 	 */
 	if (!trylock && !__wt_btree_can_evict_dirty(session))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * Get a page-level lock on the parent to single-thread splits into the
diff --git a/src/third_party/wiredtiger/src/btree/col_srch.c b/src/third_party/wiredtiger/src/btree/col_srch.c
index 123b640cdf4..4b7b3d3d727 100644
--- a/src/third_party/wiredtiger/src/btree/col_srch.c
+++ b/src/third_party/wiredtiger/src/btree/col_srch.c
@@ -180,7 +180,7 @@ descend:	/*
 		}
 
 		/* Encourage races. */
-		__wt_timing_stress(session, WT_TIMING_STRESS_SPLIT_9);
+		WT_DIAGNOSTIC_YIELD;
 
 		/*
 		 * Swap the current page for the child page. If the page splits
diff --git a/src/third_party/wiredtiger/src/btree/row_srch.c b/src/third_party/wiredtiger/src/btree/row_srch.c
index a3f05a2700f..38921471d74 100644
--- a/src/third_party/wiredtiger/src/btree/row_srch.c
+++ b/src/third_party/wiredtiger/src/btree/row_srch.c
@@ -432,7 +432,7 @@ append:			if (__wt_split_descent_race(
 		}
 
 descend:	/* Encourage races. */
-		__wt_timing_stress(session, WT_TIMING_STRESS_SPLIT_9);
+		WT_DIAGNOSTIC_YIELD;
 
 		/*
 		 * Swap the current page for the child page. If the page splits
diff --git a/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c b/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
index 01740dcd953..f09c15be450 100644
--- a/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
+++ b/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
@@ -26,9 +26,10 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include "wt_internal.h"
+#include <inttypes.h>
+#include <stddef.h>
 
-#if defined(__linux__) && defined(HAVE_CRC32_HARDWARE)
+#if defined(__linux__)
 #include <asm/hwcap.h>
 #include <sys/auxv.h>
 
@@ -84,23 +85,28 @@ __wt_checksum_hw(const void *chunk, size_t len)
 }
 #endif
 
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
+#if defined(__GNUC__)
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
+    __attribute__((visibility("default")));
+#else
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
+#endif
+
 /*
- * __wt_checksum_init --
- *	WiredTiger: detect CRC hardware and set the checksum function.
+ * wiredtiger_crc32c_func --
+ *	WiredTiger: detect CRC hardware and return the checksum function.
  */
-void
-__wt_checksum_init(void)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
+uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
-#if defined(__linux__) && defined(HAVE_CRC32_HARDWARE)
+#if defined(__linux__)
 	unsigned long caps = getauxval(AT_HWCAP);
 
 	if (caps & HWCAP_CRC32)
-		__wt_process.checksum = __wt_checksum_hw;
-	else
-		__wt_process.checksum = __wt_checksum_sw;
+		return (__wt_checksum_hw);
+	return (__wt_checksum_sw);
 
 #else
-	__wt_process.checksum = __wt_checksum_sw;
+	return (__wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/checksum/power8/crc32_wrapper.c b/src/third_party/wiredtiger/src/checksum/power8/crc32_wrapper.c
index 8626fa42136..cb427ea7a67 100644
--- a/src/third_party/wiredtiger/src/checksum/power8/crc32_wrapper.c
+++ b/src/third_party/wiredtiger/src/checksum/power8/crc32_wrapper.c
@@ -1,5 +1,6 @@
 #if defined(__powerpc64__)
-#include "wt_internal.h"
+#include <inttypes.h>
+#include <stddef.h>
 
 #define CRC_TABLE
 #include "crc32_constants.h"
@@ -80,17 +81,23 @@ __wt_checksum_hw(const void *chunk, size_t len)
 	return (crc32_vpmsum(0, chunk, len));
 }
 
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
+#if defined(__GNUC__)
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
+    __attribute__((visibility("default")));
+#else
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
+#endif
+
 /*
- * __wt_checksum_init --
- *	WiredTiger: detect CRC hardware and set the checksum function.
+ * wiredtiger_crc32c_func --
+ *	WiredTiger: detect CRC hardware and return the checksum function.
  */
-void
-__wt_checksum_init(void)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
+uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
-#if defined(HAVE_CRC32_HARDWARE)
-	__wt_process.checksum = __wt_checksum_hw;
+#if defined(__powerpc64__)
+	return (__wt_checksum_hw);
 #else
-	__wt_process.checksum = __wt_checksum_sw;
+	return (__wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/checksum/software/checksum.c b/src/third_party/wiredtiger/src/checksum/software/checksum.c
index 1228c9a0ce1..4d93f8bf1ea 100644
--- a/src/third_party/wiredtiger/src/checksum/software/checksum.c
+++ b/src/third_party/wiredtiger/src/checksum/software/checksum.c
@@ -38,7 +38,8 @@
  * little endian.
  */
 
-#include "wt_internal.h"
+#include <inttypes.h>
+#include <stddef.h>
 
 /*
  * The CRC slicing tables.
@@ -1095,13 +1096,14 @@ static const uint32_t g_crc_slicing[8][256] = {
 #endif
 };
 
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
+
 /*
  * __wt_checksum_sw --
  *	Return a checksum for a chunk of memory, computed in software.
  */
 uint32_t
 __wt_checksum_sw(const void *chunk, size_t len)
-    WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
 	uint32_t crc, next;
 	size_t nqwords;
diff --git a/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c b/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
index 73199018a7d..2ff237f883e 100644
--- a/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
+++ b/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
@@ -26,9 +26,9 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include "wt_internal.h"
+#include <inttypes.h>
+#include <stddef.h>
 
-#if defined(HAVE_CRC32_HARDWARE)
 #if (defined(__amd64) || defined(__x86_64))
 /*
  * __wt_checksum_hw --
@@ -116,17 +116,21 @@ __wt_checksum_hw(const void *chunk, size_t len)
 	return (~crc);
 }
 #endif
-#endif /* HAVE_CRC32_HARDWARE */
+
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
+#if defined(__GNUC__)
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
+    __attribute__((visibility("default")));
+#else
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
+#endif
 
 /*
- * __wt_checksum_init --
- *	WiredTiger: detect CRC hardware and set the checksum function.
+ * wiredtiger_crc32c_func --
+ *	WiredTiger: detect CRC hardware and return the checksum function.
  */
-void
-__wt_checksum_init(void)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
+uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
-#if defined(HAVE_CRC32_HARDWARE)
 #if (defined(__amd64) || defined(__x86_64))
 	unsigned int eax, ebx, ecx, edx;
 
@@ -137,9 +141,8 @@ __wt_checksum_init(void)
 
 #define	CPUID_ECX_HAS_SSE42	(1 << 20)
 	if (ecx & CPUID_ECX_HAS_SSE42)
-		__wt_process.checksum = __wt_checksum_hw;
-	else
-		__wt_process.checksum = __wt_checksum_sw;
+		return (__wt_checksum_hw);
+	return (__wt_checksum_sw);
 
 #elif defined(_M_AMD64)
 	int cpuInfo[4];
@@ -148,14 +151,10 @@ __wt_checksum_init(void)
 
 #define	CPUID_ECX_HAS_SSE42	(1 << 20)
 	if (cpuInfo[2] & CPUID_ECX_HAS_SSE42)
-		__wt_process.checksum = __wt_checksum_hw;
-	else
-		__wt_process.checksum = __wt_checksum_sw;
+		return (__wt_checksum_hw);
+	return (__wt_checksum_sw);
+
 #else
-	__wt_process.checksum = __wt_checksum_sw;
+	return (__wt_checksum_sw);
 #endif
-
-#else /* !HAVE_CRC32_HARDWARE */
-	__wt_process.checksum = __wt_checksum_sw;
-#endif /* HAVE_CRC32_HARDWARE */
 }
diff --git a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
index ec7adb02cba..72117d7509d 100644
--- a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
+++ b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
@@ -6,12 +6,13 @@
  * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  *
  */
-#include "wt_internal.h"
 
 #include <sys/types.h>
 #include <endian.h>
+#include <inttypes.h>
+#include <stddef.h>
 
-#if defined(__linux__) && defined(HAVE_CRC32_HARDWARE)
+#if defined(__linux__)
 #include <sys/auxv.h>
 
 /* RHEL 7 has kernel support, but does not define this constant in the lib c headers. */
@@ -92,23 +93,29 @@ __wt_checksum_hw(const void *chunk, size_t len)
 
 #endif
 
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
+#if defined(__GNUC__)
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
+    __attribute__((visibility("default")));
+#else
+extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
+#endif
+
 /*
- * __wt_checksum_init --
- *      WiredTiger: detect CRC hardware and set the checksum function.
+ * wiredtiger_crc32c_func --
+ *	WiredTiger: detect CRC hardware and return the checksum function.
  */
-void
-__wt_checksum_init(void)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
+uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
-#if defined(__linux__) && defined(HAVE_CRC32_HARDWARE)
+#if defined(__linux__)
 	unsigned long caps = getauxval(AT_HWCAP);
 
 	if (caps & HWCAP_S390_VX)
-		__wt_process.checksum = __wt_checksum_hw;
+		return (__wt_checksum_hw);
 	else
-		__wt_process.checksum = __wt_checksum_sw;
+		return (__wt_checksum_sw);
 
 #else
-	__wt_process.checksum = __wt_checksum_sw;
+	return (__wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/config/config_def.c b/src/third_party/wiredtiger/src/config/config_def.c
index 0945d768ce2..abbea9b1bb9 100644
--- a/src/third_party/wiredtiger/src/config/config_def.c
+++ b/src/third_party/wiredtiger/src/config/config_def.c
@@ -190,17 +190,18 @@ static const WT_CONFIG_CHECK confchk_WT_CONNECTION_reconfigure[] = {
 	{ "timing_stress_for_test", "list",
 	    NULL, "choices=[\"checkpoint_slow\",\"lookaside_sweep_race\","
 	    "\"split_1\",\"split_2\",\"split_3\",\"split_4\",\"split_5\","
-	    "\"split_6\",\"split_7\",\"split_8\",\"split_9\"]",
+	    "\"split_6\",\"split_7\",\"split_8\"]",
 	    NULL, 0 },
 	{ "verbose", "list",
 	    NULL, "choices=[\"api\",\"block\",\"checkpoint\","
-	    "\"checkpoint_progress\",\"compact\",\"evict\",\"evict_stuck\","
-	    "\"evictserver\",\"fileops\",\"handleops\",\"log\",\"lookaside\","
-	    "\"lookaside_activity\",\"lsm\",\"lsm_manager\",\"metadata\","
-	    "\"mutex\",\"overflow\",\"read\",\"rebalance\",\"reconcile\","
-	    "\"recovery\",\"recovery_progress\",\"salvage\",\"shared_cache\","
-	    "\"split\",\"temporary\",\"thread_group\",\"timestamp\","
-	    "\"transaction\",\"verify\",\"version\",\"write\"]",
+	    "\"checkpoint_progress\",\"compact\",\"error_returns\",\"evict\","
+	    "\"evict_stuck\",\"evictserver\",\"fileops\",\"handleops\","
+	    "\"log\",\"lookaside\",\"lookaside_activity\",\"lsm\","
+	    "\"lsm_manager\",\"metadata\",\"mutex\",\"overflow\",\"read\","
+	    "\"rebalance\",\"reconcile\",\"recovery\",\"recovery_progress\","
+	    "\"salvage\",\"shared_cache\",\"split\",\"temporary\","
+	    "\"thread_group\",\"timestamp\",\"transaction\",\"verify\","
+	    "\"version\",\"write\"]",
 	    NULL, 0 },
 	{ NULL, NULL, NULL, NULL, NULL, 0 }
 };
@@ -774,7 +775,7 @@ static const WT_CONFIG_CHECK
 	{ "path", "string", NULL, NULL, NULL, 0 },
 	{ "prealloc", "boolean", NULL, NULL, NULL, 0 },
 	{ "recover", "string",
-	    NULL, "choices=[\"error\",\"on\"]",
+	    NULL, "choices=[\"error\",\"on\",\"salvage\"]",
 	    NULL, 0 },
 	{ "zero_fill", "boolean", NULL, NULL, NULL, 0 },
 	{ NULL, NULL, NULL, NULL, NULL, 0 }
@@ -881,7 +882,7 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open[] = {
 	{ "timing_stress_for_test", "list",
 	    NULL, "choices=[\"checkpoint_slow\",\"lookaside_sweep_race\","
 	    "\"split_1\",\"split_2\",\"split_3\",\"split_4\",\"split_5\","
-	    "\"split_6\",\"split_7\",\"split_8\",\"split_9\"]",
+	    "\"split_6\",\"split_7\",\"split_8\"]",
 	    NULL, 0 },
 	{ "transaction_sync", "category",
 	    NULL, NULL,
@@ -890,13 +891,14 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open[] = {
 	{ "use_environment_priv", "boolean", NULL, NULL, NULL, 0 },
 	{ "verbose", "list",
 	    NULL, "choices=[\"api\",\"block\",\"checkpoint\","
-	    "\"checkpoint_progress\",\"compact\",\"evict\",\"evict_stuck\","
-	    "\"evictserver\",\"fileops\",\"handleops\",\"log\",\"lookaside\","
-	    "\"lookaside_activity\",\"lsm\",\"lsm_manager\",\"metadata\","
-	    "\"mutex\",\"overflow\",\"read\",\"rebalance\",\"reconcile\","
-	    "\"recovery\",\"recovery_progress\",\"salvage\",\"shared_cache\","
-	    "\"split\",\"temporary\",\"thread_group\",\"timestamp\","
-	    "\"transaction\",\"verify\",\"version\",\"write\"]",
+	    "\"checkpoint_progress\",\"compact\",\"error_returns\",\"evict\","
+	    "\"evict_stuck\",\"evictserver\",\"fileops\",\"handleops\","
+	    "\"log\",\"lookaside\",\"lookaside_activity\",\"lsm\","
+	    "\"lsm_manager\",\"metadata\",\"mutex\",\"overflow\",\"read\","
+	    "\"rebalance\",\"reconcile\",\"recovery\",\"recovery_progress\","
+	    "\"salvage\",\"shared_cache\",\"split\",\"temporary\","
+	    "\"thread_group\",\"timestamp\",\"transaction\",\"verify\","
+	    "\"version\",\"write\"]",
 	    NULL, 0 },
 	{ "write_through", "list",
 	    NULL, "choices=[\"data\",\"log\"]",
@@ -985,7 +987,7 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open_all[] = {
 	{ "timing_stress_for_test", "list",
 	    NULL, "choices=[\"checkpoint_slow\",\"lookaside_sweep_race\","
 	    "\"split_1\",\"split_2\",\"split_3\",\"split_4\",\"split_5\","
-	    "\"split_6\",\"split_7\",\"split_8\",\"split_9\"]",
+	    "\"split_6\",\"split_7\",\"split_8\"]",
 	    NULL, 0 },
 	{ "transaction_sync", "category",
 	    NULL, NULL,
@@ -994,13 +996,14 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open_all[] = {
 	{ "use_environment_priv", "boolean", NULL, NULL, NULL, 0 },
 	{ "verbose", "list",
 	    NULL, "choices=[\"api\",\"block\",\"checkpoint\","
-	    "\"checkpoint_progress\",\"compact\",\"evict\",\"evict_stuck\","
-	    "\"evictserver\",\"fileops\",\"handleops\",\"log\",\"lookaside\","
-	    "\"lookaside_activity\",\"lsm\",\"lsm_manager\",\"metadata\","
-	    "\"mutex\",\"overflow\",\"read\",\"rebalance\",\"reconcile\","
-	    "\"recovery\",\"recovery_progress\",\"salvage\",\"shared_cache\","
-	    "\"split\",\"temporary\",\"thread_group\",\"timestamp\","
-	    "\"transaction\",\"verify\",\"version\",\"write\"]",
+	    "\"checkpoint_progress\",\"compact\",\"error_returns\",\"evict\","
+	    "\"evict_stuck\",\"evictserver\",\"fileops\",\"handleops\","
+	    "\"log\",\"lookaside\",\"lookaside_activity\",\"lsm\","
+	    "\"lsm_manager\",\"metadata\",\"mutex\",\"overflow\",\"read\","
+	    "\"rebalance\",\"reconcile\",\"recovery\",\"recovery_progress\","
+	    "\"salvage\",\"shared_cache\",\"split\",\"temporary\","
+	    "\"thread_group\",\"timestamp\",\"transaction\",\"verify\","
+	    "\"version\",\"write\"]",
 	    NULL, 0 },
 	{ "version", "string", NULL, NULL, NULL, 0 },
 	{ "write_through", "list",
@@ -1086,20 +1089,21 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open_basecfg[] = {
 	{ "timing_stress_for_test", "list",
 	    NULL, "choices=[\"checkpoint_slow\",\"lookaside_sweep_race\","
 	    "\"split_1\",\"split_2\",\"split_3\",\"split_4\",\"split_5\","
-	    "\"split_6\",\"split_7\",\"split_8\",\"split_9\"]",
+	    "\"split_6\",\"split_7\",\"split_8\"]",
 	    NULL, 0 },
 	{ "transaction_sync", "category",
 	    NULL, NULL,
 	    confchk_wiredtiger_open_transaction_sync_subconfigs, 2 },
 	{ "verbose", "list",
 	    NULL, "choices=[\"api\",\"block\",\"checkpoint\","
-	    "\"checkpoint_progress\",\"compact\",\"evict\",\"evict_stuck\","
-	    "\"evictserver\",\"fileops\",\"handleops\",\"log\",\"lookaside\","
-	    "\"lookaside_activity\",\"lsm\",\"lsm_manager\",\"metadata\","
-	    "\"mutex\",\"overflow\",\"read\",\"rebalance\",\"reconcile\","
-	    "\"recovery\",\"recovery_progress\",\"salvage\",\"shared_cache\","
-	    "\"split\",\"temporary\",\"thread_group\",\"timestamp\","
-	    "\"transaction\",\"verify\",\"version\",\"write\"]",
+	    "\"checkpoint_progress\",\"compact\",\"error_returns\",\"evict\","
+	    "\"evict_stuck\",\"evictserver\",\"fileops\",\"handleops\","
+	    "\"log\",\"lookaside\",\"lookaside_activity\",\"lsm\","
+	    "\"lsm_manager\",\"metadata\",\"mutex\",\"overflow\",\"read\","
+	    "\"rebalance\",\"reconcile\",\"recovery\",\"recovery_progress\","
+	    "\"salvage\",\"shared_cache\",\"split\",\"temporary\","
+	    "\"thread_group\",\"timestamp\",\"transaction\",\"verify\","
+	    "\"version\",\"write\"]",
 	    NULL, 0 },
 	{ "version", "string", NULL, NULL, NULL, 0 },
 	{ "write_through", "list",
@@ -1185,20 +1189,21 @@ static const WT_CONFIG_CHECK confchk_wiredtiger_open_usercfg[] = {
 	{ "timing_stress_for_test", "list",
 	    NULL, "choices=[\"checkpoint_slow\",\"lookaside_sweep_race\","
 	    "\"split_1\",\"split_2\",\"split_3\",\"split_4\",\"split_5\","
-	    "\"split_6\",\"split_7\",\"split_8\",\"split_9\"]",
+	    "\"split_6\",\"split_7\",\"split_8\"]",
 	    NULL, 0 },
 	{ "transaction_sync", "category",
 	    NULL, NULL,
 	    confchk_wiredtiger_open_transaction_sync_subconfigs, 2 },
 	{ "verbose", "list",
 	    NULL, "choices=[\"api\",\"block\",\"checkpoint\","
-	    "\"checkpoint_progress\",\"compact\",\"evict\",\"evict_stuck\","
-	    "\"evictserver\",\"fileops\",\"handleops\",\"log\",\"lookaside\","
-	    "\"lookaside_activity\",\"lsm\",\"lsm_manager\",\"metadata\","
-	    "\"mutex\",\"overflow\",\"read\",\"rebalance\",\"reconcile\","
-	    "\"recovery\",\"recovery_progress\",\"salvage\",\"shared_cache\","
-	    "\"split\",\"temporary\",\"thread_group\",\"timestamp\","
-	    "\"transaction\",\"verify\",\"version\",\"write\"]",
+	    "\"checkpoint_progress\",\"compact\",\"error_returns\",\"evict\","
+	    "\"evict_stuck\",\"evictserver\",\"fileops\",\"handleops\","
+	    "\"log\",\"lookaside\",\"lookaside_activity\",\"lsm\","
+	    "\"lsm_manager\",\"metadata\",\"mutex\",\"overflow\",\"read\","
+	    "\"rebalance\",\"reconcile\",\"recovery\",\"recovery_progress\","
+	    "\"salvage\",\"shared_cache\",\"split\",\"temporary\","
+	    "\"thread_group\",\"timestamp\",\"transaction\",\"verify\","
+	    "\"version\",\"write\"]",
 	    NULL, 0 },
 	{ "write_through", "list",
 	    NULL, "choices=[\"data\",\"log\"]",
diff --git a/src/third_party/wiredtiger/src/conn/conn_api.c b/src/third_party/wiredtiger/src/conn/conn_api.c
index 589560acc88..47ab622a7f4 100644
--- a/src/third_party/wiredtiger/src/conn/conn_api.c
+++ b/src/third_party/wiredtiger/src/conn/conn_api.c
@@ -1832,6 +1832,7 @@ __wt_verbose_config(WT_SESSION_IMPL *session, const char *cfg[])
 		{ "checkpoint",		WT_VERB_CHECKPOINT },
 		{ "checkpoint_progress",WT_VERB_CHECKPOINT_PROGRESS },
 		{ "compact",		WT_VERB_COMPACT },
+		{ "error_returns",      WT_VERB_ERROR_RETURNS },
 		{ "evict",		WT_VERB_EVICT },
 		{ "evict_stuck",	WT_VERB_EVICT_STUCK },
 		{ "evictserver",	WT_VERB_EVICTSERVER },
@@ -2025,7 +2026,6 @@ __wt_timing_stress_config(WT_SESSION_IMPL *session, const char *cfg[])
 		{ "split_6",		WT_TIMING_STRESS_SPLIT_6 },
 		{ "split_7",		WT_TIMING_STRESS_SPLIT_7 },
 		{ "split_8",		WT_TIMING_STRESS_SPLIT_8 },
-		{ "split_9",		WT_TIMING_STRESS_SPLIT_9 },
 		{ NULL, 0 }
 	};
 	WT_CONFIG_ITEM cval, sval;
@@ -2750,15 +2750,3 @@ err:	/* Discard the scratch buffers. */
 
 	return (ret);
 }
-
-/*
- * wiredtiger_checksum_crc32c --
- *	CRC32C checksum function entry point.
- */
-uint32_t
-wiredtiger_checksum_crc32c(const void *buffer, size_t len)
-{
-	if (__wt_process.checksum == NULL)
-		__wt_checksum_init();
-	return (__wt_process.checksum(buffer, len));
-}
diff --git a/src/third_party/wiredtiger/src/conn/conn_dhandle.c b/src/third_party/wiredtiger/src/conn/conn_dhandle.c
index 7c24f3c126f..7013ade0f27 100644
--- a/src/third_party/wiredtiger/src/conn/conn_dhandle.c
+++ b/src/third_party/wiredtiger/src/conn/conn_dhandle.c
@@ -47,7 +47,7 @@ __conn_dhandle_config_set(WT_SESSION_IMPL *session)
 	if ((ret =
 	    __wt_metadata_search(session, dhandle->name, &metaconf)) != 0) {
 		if (ret == WT_NOTFOUND)
-			ret = ENOENT;
+			ret = __wt_set_return(session, ENOENT);
 		WT_RET(ret);
 	}
 
@@ -703,7 +703,7 @@ __conn_dhandle_remove(WT_SESSION_IMPL *session, bool final)
 	/* Check if the handle was reacquired by a session while we waited. */
 	if (!final &&
 	    (dhandle->session_inuse != 0 || dhandle->session_ref != 0))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	WT_CONN_DHANDLE_REMOVE(conn, dhandle, bucket);
 	return (0);
diff --git a/src/third_party/wiredtiger/src/conn/conn_log.c b/src/third_party/wiredtiger/src/conn/conn_log.c
index d8eb095d6d2..34570fdd0be 100644
--- a/src/third_party/wiredtiger/src/conn/conn_log.c
+++ b/src/third_party/wiredtiger/src/conn/conn_log.c
@@ -299,6 +299,13 @@ __logmgr_config(
 		    session, cfg, "log.recover", 0, &cval));
 		if (WT_STRING_MATCH("error", cval.str, cval.len))
 			FLD_SET(conn->log_flags, WT_CONN_LOG_RECOVER_ERR);
+		else if (WT_STRING_MATCH("salvage", cval.str, cval.len)) {
+			if (F_ISSET(conn, WT_CONN_READONLY))
+				WT_RET_MSG(session, EINVAL,
+				    "Readonly configuration incompatible with "
+				    "log=(recover=salvage)");
+			FLD_SET(conn->log_flags, WT_CONN_LOG_RECOVER_SALVAGE);
+		}
 	}
 
 	WT_RET(__wt_config_gets(session, cfg, "log.zero_fill", &cval));
diff --git a/src/third_party/wiredtiger/src/docs/config-strings.dox b/src/third_party/wiredtiger/src/docs/config-strings.dox
index a583573214f..d6291d5b4ba 100644
--- a/src/third_party/wiredtiger/src/docs/config-strings.dox
+++ b/src/third_party/wiredtiger/src/docs/config-strings.dox
@@ -44,7 +44,7 @@ columns in a table, values are nested using parentheses.  For example:
 
 All types of parentheses are treated equivalently by the parser.
 
-When an integer values is expected, the value may have multiplier characters
+When an integer value is expected, the value may have multiplier characters
 appended, as follows:
 
 <table>
diff --git a/src/third_party/wiredtiger/src/docs/top/main.dox b/src/third_party/wiredtiger/src/docs/top/main.dox
index e4de22ff042..d802443a9d8 100644
--- a/src/third_party/wiredtiger/src/docs/top/main.dox
+++ b/src/third_party/wiredtiger/src/docs/top/main.dox
@@ -6,12 +6,12 @@ WiredTiger is an high performance, scalable, production quality, NoSQL,
 @section releases Releases
 
 <table>
-@row{<b>WiredTiger 3.0.0</b> (current),
+@row{<b>WiredTiger 3.1.0</b> (current),
+	<a href="releases/wiredtiger-3.1.0.tar.bz2"><b>[Release package]</b></a>,
+	<a href="3.1.0/index.html"><b>[Documentation]</b></a>}
+@row{<b>WiredTiger 3.0.0</b> (previous),
 	<a href="releases/wiredtiger-3.0.0.tar.bz2"><b>[Release package]</b></a>,
 	<a href="3.0.0/index.html"><b>[Documentation]</b></a>}
-@row{<b>WiredTiger 2.9.3</b> (previous),
-	<a href="releases/wiredtiger-2.9.3.tar.bz2"><b>[Release package]</b></a>,
-	<a href="2.9.3/index.html"><b>[Documentation]</b></a>}
 @row{<b>Development branch</b>,
 	<a href="https://github.com/wiredtiger/wiredtiger"><b>[Source code]</b></a>,
 	<a href="develop/index.html"><b>[Documentation]</b></a>}
diff --git a/src/third_party/wiredtiger/src/docs/upgrading.dox b/src/third_party/wiredtiger/src/docs/upgrading.dox
index 2e4990e8a33..7e89d23230f 100644
--- a/src/third_party/wiredtiger/src/docs/upgrading.dox
+++ b/src/third_party/wiredtiger/src/docs/upgrading.dox
@@ -1,5 +1,61 @@
 /*! @page upgrading Upgrading WiredTiger applications
+@section version_310 Upgrading to Version 3.1.0
+<dl>
+
+<dt>WiredTiger on-disk log file format change</dt>
+<dd>
+The WiredTiger on-disk file format for write-ahead log files has changed
+as the log file version number was incremented. See
+<a href=https://jira.mongodb.org/browse/WT-4029>WT-4029</a> for details.
+</dd>
+
+<dt>::wiredtiger_open compatibility configuration changes</dt>
+<dd>
+The compatibility setting now takes additional options that can define
+the minimum or maximum required version of existing data files. See
+<a href=https://jira.mongodb.org/browse/WT-4056>WT-4056</a> and
+<a href=https://jira.mongodb.org/browse/WT-4098>WT-4098</a> for details.
+</dd>
 
+<dt>::wiredtiger_open cache configuration changes</dt>
+<dd>
+The cache configuration options \c eviction_checkpoint_target, \c
+eviction_dirty_target, \c eviction_dirty_trigger, \c eviction_target and \c
+eviction_trigger have changed. The options can now take an absolute size. It would
+be a percentage of the cache size if the value is within the range of 0 to 100
+or an absolute size when greater than 100. This API change is compatible with
+existing usage. See <a href=https://jira.mongodb.org/browse/WT-3632>WT-3632</a>
+for details.
+</dd>
+
+<dt>Changed transaction semantics around schema operations</dt>
+<dd>
+WiredTiger does not offer fully transactional create and drop operations.
+We have made some changes to how create and drop are implemented
+if done within the scope of an explicit transaction. If an application
+is relying on particular visibility/atomicity guarantees around table
+create or drop, care should be taken when upgrading. See
+<a href=https://jira.mongodb.org/browse/WT-3964>WT-3964</a> for details.
+</dd>
+
+<dt>On-disk format change for metadata</dt>
+<dd>
+There was a change to the content stored in the WiredTiger owned metadata
+files, which means metadata created or updated by this version of WiredTiger
+is not compatible with earlier versions. See
+<a href=https://jira.mongodb.org/browse/WT-3905>WT-3905</a> for details.
+</dd>
+
+<dt>Implement a per-session cursor cache</dt>
+<dd>
+WiredTiger now holds a cache of recently closed cursors in each
+session. This improves performance for applications that open and
+close cursors frequently, but increases memory overhead. The cache
+is enabled by default, but can be disabled. See
+<a href=https://jira.mongodb.org/browse/WT-1228>WT-1228</a> for details.
+</dd>
+
+</dl><hr>
 @section version_300 Upgrading to Version 3.0.0
 <dl>
 
@@ -28,16 +84,6 @@ The performance visualization tool \c wtstats has been removed and is
 no longer supported.
 </dd>
 
-<dt>::wiredtiger_open cache configuration changes</dt>
-<dd>
-The cache configuration options \c eviction_checkpoint_target, \c
-eviction_dirty_target, \c eviction_dirty_trigger, \c eviction_target and \c
-eviction_trigger have changed. The options can now take absolute size. It would
-be a percentage of the cache size if the value is within the range of 0 to 100
-or an absolute size when greater than 100. This API change is compatible with
-existing usage.
-</dd>
-
 </dl><hr>
 @section version_292 Upgrading to Version 2.9.2
 <dl>
diff --git a/src/third_party/wiredtiger/src/evict/evict_lru.c b/src/third_party/wiredtiger/src/evict/evict_lru.c
index 05397843fc7..13b5dfc4c8d 100644
--- a/src/third_party/wiredtiger/src/evict/evict_lru.c
+++ b/src/third_party/wiredtiger/src/evict/evict_lru.c
@@ -451,7 +451,7 @@ __evict_server(WT_SESSION_IMPL *session, bool *did_work)
 		    "Cache stuck for too long, giving up");
 		WT_RET(__wt_verbose_dump_txn(session));
 		WT_RET(__wt_verbose_dump_cache(session));
-		return (ETIMEDOUT);
+		return (__wt_set_return(session, ETIMEDOUT));
 #else
 		if (WT_VERBOSE_ISSET(session, WT_VERB_EVICT_STUCK)) {
 			WT_RET(__wt_verbose_dump_txn(session));
diff --git a/src/third_party/wiredtiger/src/evict/evict_page.c b/src/third_party/wiredtiger/src/evict/evict_page.c
index 0daccdf5b1c..71e084773d0 100644
--- a/src/third_party/wiredtiger/src/evict/evict_page.c
+++ b/src/third_party/wiredtiger/src/evict/evict_page.c
@@ -42,7 +42,7 @@ __evict_exclusive(WT_SESSION_IMPL *session, WT_REF *ref)
 
 	WT_STAT_DATA_INCR(session, cache_eviction_hazard);
 	WT_STAT_CONN_INCR(session, cache_eviction_hazard);
-	return (EBUSY);
+	return (__wt_set_return(session, EBUSY));
 }
 
 /*
@@ -453,7 +453,7 @@ __evict_child_check(WT_SESSION_IMPL *session, WT_REF *parent)
 			 * page.
 			 */
 			if (__wt_page_del_active(session, child, true))
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 			break;
 		case WT_REF_LOOKASIDE:
 			/*
@@ -461,10 +461,10 @@ __evict_child_check(WT_SESSION_IMPL *session, WT_REF *parent)
 			 * can be ignored.
 			 */
 			if (__wt_page_las_active(session, child))
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 			break;
 		default:
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		}
 	} WT_INTL_FOREACH_END;
 
@@ -528,7 +528,7 @@ __evict_review(
 	 * should be uncommon - we don't add clean pages to the queue.
 	 */
 	if (F_ISSET(conn, WT_CONN_IN_MEMORY) && !modified && !closing)
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/* Check if the page can be evicted. */
 	if (!closing) {
@@ -541,7 +541,7 @@ __evict_review(
 			    session, WT_TXN_OLDEST_STRICT));
 
 		if (!__wt_page_can_evict(session, ref, inmem_splitp))
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 
 		/*
 		 * Check for an append-only workload needing an in-memory
@@ -563,7 +563,7 @@ __evict_review(
 	 * eviction that writes to lookaside), give up.
 	 */
 	if (F_ISSET(session, WT_SESSION_NO_RECONCILE))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * If the page is dirty, reconcile it to decide if we can evict it.
@@ -636,7 +636,7 @@ __evict_review(
 	if (WT_SESSION_IS_CHECKPOINT(session) && !__wt_page_is_modified(page) &&
 	    !__wt_txn_visible_all(session, page->modify->rec_max_txn,
 	    WT_TIMESTAMP_NULL(&page->modify->rec_max_timestamp)))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * If reconciliation fails but reports it might succeed if we use the
@@ -663,7 +663,7 @@ __evict_review(
 	 */
 	if (WT_SESSION_IS_CHECKPOINT(session) &&
 	    page->modify->rec_result == WT_PM_REC_MULTIBLOCK)
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * Success: assert the page is clean or reconciliation was configured
diff --git a/src/third_party/wiredtiger/src/include/btree.i b/src/third_party/wiredtiger/src/include/btree.i
index 7813f1299fd..ed3480a40d0 100644
--- a/src/third_party/wiredtiger/src/include/btree.i
+++ b/src/third_party/wiredtiger/src/include/btree.i
@@ -1357,13 +1357,12 @@ __wt_page_evict_retry(WT_SESSION_IMPL *session, WT_PAGE *page)
 		return (true);
 
 #ifdef HAVE_TIMESTAMPS
-	if (!__wt_timestamp_iszero(&mod->last_eviction_timestamp)) {
-		__wt_txn_pinned_timestamp(session, &pinned_ts);
-		if (__wt_timestamp_cmp(
-		    &mod->last_eviction_timestamp,
-		    &txn_global->pinned_timestamp) != 0)
-			return (true);
-	}
+	if (__wt_timestamp_iszero(&mod->last_eviction_timestamp))
+		return (true);
+
+	__wt_txn_pinned_timestamp(session, &pinned_ts);
+	if (__wt_timestamp_cmp(&pinned_ts, &mod->last_eviction_timestamp) > 0)
+		return (true);
 #endif
 
 	return (false);
diff --git a/src/third_party/wiredtiger/src/include/cache.i b/src/third_party/wiredtiger/src/include/cache.i
index 7f12949e162..2e3700f6287 100644
--- a/src/third_party/wiredtiger/src/include/cache.i
+++ b/src/third_party/wiredtiger/src/include/cache.i
@@ -220,9 +220,9 @@ __wt_cache_update_lookaside_score(
 	global_score = cache->evict_lookaside_score;
 
 	if (score > global_score && global_score < 100)
-		__wt_atomic_addi32(&cache->evict_lookaside_score, 1);
+		(void)__wt_atomic_addi32(&cache->evict_lookaside_score, 1);
 	else if (score < global_score && global_score > 0)
-		__wt_atomic_subi32(&cache->evict_lookaside_score, 1);
+		(void)__wt_atomic_subi32(&cache->evict_lookaside_score, 1);
 }
 
 /*
diff --git a/src/third_party/wiredtiger/src/include/connection.h b/src/third_party/wiredtiger/src/include/connection.h
index 22459b0072c..19bb21ce2f1 100644
--- a/src/third_party/wiredtiger/src/include/connection.h
+++ b/src/third_party/wiredtiger/src/include/connection.h
@@ -322,7 +322,8 @@ struct __wt_connection_impl {
 #define	WT_CONN_LOG_RECOVER_DIRTY	0x020u	/* Recovering unclean */
 #define	WT_CONN_LOG_RECOVER_DONE	0x040u	/* Recovery completed */
 #define	WT_CONN_LOG_RECOVER_ERR		0x080u	/* Error if recovery required */
-#define	WT_CONN_LOG_ZERO_FILL		0x100u	/* Manually zero files */
+#define	WT_CONN_LOG_RECOVER_SALVAGE	0x100u	/* Salvage log files */
+#define	WT_CONN_LOG_ZERO_FILL		0x200u	/* Manually zero files */
 /* AUTOMATIC FLAG VALUE GENERATION STOP */
 	uint32_t	 log_flags;	/* Global logging configuration */
 	WT_CONDVAR	*log_cond;	/* Log server wait mutex */
@@ -413,34 +414,35 @@ struct __wt_connection_impl {
 #define	WT_VERB_CHECKPOINT		0x000000004u
 #define	WT_VERB_CHECKPOINT_PROGRESS	0x000000008u
 #define	WT_VERB_COMPACT			0x000000010u
-#define	WT_VERB_EVICT			0x000000020u
-#define	WT_VERB_EVICTSERVER		0x000000040u
-#define	WT_VERB_EVICT_STUCK		0x000000080u
-#define	WT_VERB_FILEOPS			0x000000100u
-#define	WT_VERB_HANDLEOPS		0x000000200u
-#define	WT_VERB_LOG			0x000000400u
-#define	WT_VERB_LOOKASIDE		0x000000800u
-#define	WT_VERB_LOOKASIDE_ACTIVITY	0x000001000u
-#define	WT_VERB_LSM			0x000002000u
-#define	WT_VERB_LSM_MANAGER		0x000004000u
-#define	WT_VERB_METADATA		0x000008000u
-#define	WT_VERB_MUTEX			0x000010000u
-#define	WT_VERB_OVERFLOW		0x000020000u
-#define	WT_VERB_READ			0x000040000u
-#define	WT_VERB_REBALANCE		0x000080000u
-#define	WT_VERB_RECONCILE		0x000100000u
-#define	WT_VERB_RECOVERY		0x000200000u
-#define	WT_VERB_RECOVERY_PROGRESS	0x000400000u
-#define	WT_VERB_SALVAGE			0x000800000u
-#define	WT_VERB_SHARED_CACHE		0x001000000u
-#define	WT_VERB_SPLIT			0x002000000u
-#define	WT_VERB_TEMPORARY		0x004000000u
-#define	WT_VERB_THREAD_GROUP		0x008000000u
-#define	WT_VERB_TIMESTAMP		0x010000000u
-#define	WT_VERB_TRANSACTION		0x020000000u
-#define	WT_VERB_VERIFY			0x040000000u
-#define	WT_VERB_VERSION			0x080000000u
-#define	WT_VERB_WRITE			0x100000000u
+#define	WT_VERB_ERROR_RETURNS		0x000000020u
+#define	WT_VERB_EVICT			0x000000040u
+#define	WT_VERB_EVICTSERVER		0x000000080u
+#define	WT_VERB_EVICT_STUCK		0x000000100u
+#define	WT_VERB_FILEOPS			0x000000200u
+#define	WT_VERB_HANDLEOPS		0x000000400u
+#define	WT_VERB_LOG			0x000000800u
+#define	WT_VERB_LOOKASIDE		0x000001000u
+#define	WT_VERB_LOOKASIDE_ACTIVITY	0x000002000u
+#define	WT_VERB_LSM			0x000004000u
+#define	WT_VERB_LSM_MANAGER		0x000008000u
+#define	WT_VERB_METADATA		0x000010000u
+#define	WT_VERB_MUTEX			0x000020000u
+#define	WT_VERB_OVERFLOW		0x000040000u
+#define	WT_VERB_READ			0x000080000u
+#define	WT_VERB_REBALANCE		0x000100000u
+#define	WT_VERB_RECONCILE		0x000200000u
+#define	WT_VERB_RECOVERY		0x000400000u
+#define	WT_VERB_RECOVERY_PROGRESS	0x000800000u
+#define	WT_VERB_SALVAGE			0x001000000u
+#define	WT_VERB_SHARED_CACHE		0x002000000u
+#define	WT_VERB_SPLIT			0x004000000u
+#define	WT_VERB_TEMPORARY		0x008000000u
+#define	WT_VERB_THREAD_GROUP		0x010000000u
+#define	WT_VERB_TIMESTAMP		0x020000000u
+#define	WT_VERB_TRANSACTION		0x040000000u
+#define	WT_VERB_VERIFY			0x080000000u
+#define	WT_VERB_VERSION			0x100000000u
+#define	WT_VERB_WRITE			0x200000000u
 /* AUTOMATIC FLAG VALUE GENERATION STOP */
 	uint64_t verbose;
 
@@ -459,7 +461,6 @@ struct __wt_connection_impl {
 #define	WT_TIMING_STRESS_SPLIT_6		0x080u
 #define	WT_TIMING_STRESS_SPLIT_7		0x100u
 #define	WT_TIMING_STRESS_SPLIT_8		0x200u
-#define	WT_TIMING_STRESS_SPLIT_9		0x400u
 /* AUTOMATIC FLAG VALUE GENERATION STOP */
 	uint64_t timing_stress_flags;
 
diff --git a/src/third_party/wiredtiger/src/include/error.h b/src/third_party/wiredtiger/src/include/error.h
index f94c3d7b880..c85f67e6f0b 100644
--- a/src/third_party/wiredtiger/src/include/error.h
+++ b/src/third_party/wiredtiger/src/include/error.h
@@ -19,6 +19,13 @@
 #define	WT_DIAGNOSTIC_YIELD
 #endif
 
+#define	__wt_err(session, error, ...)					\
+	__wt_err_func(session, error, __func__, __LINE__, __VA_ARGS__)
+#define	__wt_errx(session, ...)						\
+	__wt_errx_func(session, __func__, __LINE__, __VA_ARGS__)
+#define	__wt_set_return(session, error)					\
+	__wt_set_return_func(session, __func__, __LINE__, error)
+
 /* Set "ret" and branch-to-err-label tests. */
 #define	WT_ERR(a) do {							\
 	if ((ret = (a)) != 0)						\
@@ -125,8 +132,10 @@
  */
 #ifdef HAVE_DIAGNOSTIC
 #define	WT_ASSERT(session, exp) do {					\
-	if (!(exp))							\
-		__wt_assert(session, 0, __func__, __LINE__, "%s", #exp);\
+	if (!(exp)) {							\
+		__wt_errx(session, "%s", #exp);				\
+		__wt_abort(session);					\
+	}								\
 } while (0)
 #else
 #define	WT_ASSERT(session, exp)						\
diff --git a/src/third_party/wiredtiger/src/include/extern.h b/src/third_party/wiredtiger/src/include/extern.h
index 24e16adefd1..6df9da759c3 100644
--- a/src/third_party/wiredtiger/src/include/extern.h
+++ b/src/third_party/wiredtiger/src/include/extern.h
@@ -215,8 +215,7 @@ extern int __wt_las_cursor_position(WT_CURSOR *cursor, uint64_t pageid) WT_GCC_F
 extern int __wt_las_remove_block(WT_SESSION_IMPL *session, uint64_t pageid, bool lock_wait) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_las_save_dropped(WT_SESSION_IMPL *session) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_las_sweep(WT_SESSION_IMPL *session) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
-extern uint32_t __wt_checksum_sw(const void *chunk, size_t len) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
-extern void __wt_checksum_init(void) WT_GCC_FUNC_DECL_ATTRIBUTE((cold));
+extern uint32_t __wt_checksum_sw(const void *chunk, size_t len);
 extern void __wt_config_initn(WT_SESSION_IMPL *session, WT_CONFIG *conf, const char *str, size_t len);
 extern void __wt_config_init(WT_SESSION_IMPL *session, WT_CONFIG *conf, const char *str);
 extern void __wt_config_subinit(WT_SESSION_IMPL *session, WT_CONFIG *conf, WT_CONFIG_ITEM *item);
@@ -549,7 +548,7 @@ extern int __wt_nfilename(WT_SESSION_IMPL *session, const char *name, size_t nam
 extern int __wt_filename_construct(WT_SESSION_IMPL *session, const char *path, const char *file_prefix, uintmax_t id_1, uint32_t id_2, WT_ITEM *buf) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_remove_if_exists(WT_SESSION_IMPL *session, const char *name, bool durable) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_copy_and_sync(WT_SESSION *wt_session, const char *from, const char *to) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default"))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
-extern void __wt_abort(WT_SESSION_IMPL *session) WT_GCC_FUNC_DECL_ATTRIBUTE((noreturn));
+extern void __wt_abort(WT_SESSION_IMPL *session) WT_GCC_FUNC_DECL_ATTRIBUTE((noreturn)) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
 extern int __wt_calloc(WT_SESSION_IMPL *session, size_t number, size_t size, void *retp) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default"))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_malloc(WT_SESSION_IMPL *session, size_t bytes_to_allocate, void *retp) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_realloc(WT_SESSION_IMPL *session, size_t *bytes_allocated_ret, size_t bytes_to_allocate, void *retp) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
@@ -676,23 +675,15 @@ extern int __wt_decrypt(WT_SESSION_IMPL *session, WT_ENCRYPTOR *encryptor, size_
 extern int __wt_encrypt(WT_SESSION_IMPL *session, WT_KEYED_ENCRYPTOR *kencryptor, size_t skip, WT_ITEM *in, WT_ITEM *out) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern void __wt_encrypt_size(WT_SESSION_IMPL *session, WT_KEYED_ENCRYPTOR *kencryptor, size_t incoming_size, size_t *sizep);
 extern void __wt_event_handler_set(WT_SESSION_IMPL *session, WT_EVENT_HANDLER *handler);
-extern void __wt_err(WT_SESSION_IMPL *session, int error, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 3, 4))) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
-extern void __wt_errx(WT_SESSION_IMPL *session, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 2, 3)));
+extern void __wt_err_func(WT_SESSION_IMPL *session, int error, const char *func_name, int line_number, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 5, 6))) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
+extern void __wt_errx_func(WT_SESSION_IMPL *session, const char *func_name, int line_number, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 4, 5))) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
+extern int __wt_set_return_func(WT_SESSION_IMPL *session, const char*func, int line, int err) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_ext_err_printf(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 3, 4))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern void __wt_verbose_worker(WT_SESSION_IMPL *session, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 2, 3))) WT_GCC_FUNC_DECL_ATTRIBUTE((cold));
 extern int __wt_msg(WT_SESSION_IMPL *session, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 2, 3))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_ext_msg_printf(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, const char *fmt, ...) WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 3, 4))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern const char *__wt_ext_strerror(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, int error);
 extern int __wt_progress(WT_SESSION_IMPL *session, const char *s, uint64_t v) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
-extern void
-__wt_assert(WT_SESSION_IMPL *session,
- int error, const char *file_name, int line_number, const char *fmt, ...)
- WT_GCC_FUNC_DECL_ATTRIBUTE((cold))
- WT_GCC_FUNC_DECL_ATTRIBUTE((format (printf, 5, 6)))
-#ifdef HAVE_DIAGNOSTIC
- WT_GCC_FUNC_DECL_ATTRIBUTE((noreturn))
-#endif
- WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default")));
 extern int __wt_panic(WT_SESSION_IMPL *session) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default"))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_illegal_value_func(WT_SESSION_IMPL *session, const char *tag, const char *file, int line) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((visibility("default"))) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_inmem_unsupported_op(WT_SESSION_IMPL *session, const char *tag) WT_GCC_FUNC_DECL_ATTRIBUTE((cold)) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
@@ -724,6 +715,7 @@ extern int __wt_hazard_clear(WT_SESSION_IMPL *session, WT_REF *ref) WT_GCC_FUNC_
 extern void __wt_hazard_close(WT_SESSION_IMPL *session);
 extern WT_HAZARD *__wt_hazard_check(WT_SESSION_IMPL *session, WT_REF *ref);
 extern u_int __wt_hazard_count(WT_SESSION_IMPL *session, WT_REF *ref);
+extern bool __wt_hazard_check_assert(WT_SESSION_IMPL *session, void *ref, bool waitfor) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern void __wt_fill_hex(const uint8_t *src, size_t src_max, uint8_t *dest, size_t dest_max, size_t *lenp);
 extern int __wt_raw_to_hex(WT_SESSION_IMPL *session, const uint8_t *from, size_t size, WT_ITEM *to) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 extern int __wt_raw_to_esc_hex(WT_SESSION_IMPL *session, const uint8_t *from, size_t size, WT_ITEM *to) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
diff --git a/src/third_party/wiredtiger/src/include/misc.h b/src/third_party/wiredtiger/src/include/misc.h
index 7060e6cea23..c56dea0a074 100644
--- a/src/third_party/wiredtiger/src/include/misc.h
+++ b/src/third_party/wiredtiger/src/include/misc.h
@@ -338,3 +338,50 @@ union __wt_rand_state {
 			continue;					\
 		}
 #define	WT_TAILQ_SAFE_REMOVE_END }
+
+/*
+ * WT_VA_ARGS_BUF_FORMAT --
+ *	Format into a scratch buffer, extending it as necessary. This is a
+ * macro because we need to repeatedly call va_start/va_end and there's no
+ * way to do that inside a function call.
+ */
+#define	WT_VA_ARGS_BUF_FORMAT(session, buf, fmt, concatenate) do {	\
+	size_t __len, __space;						\
+	va_list __ap;							\
+	int __ret_xx;		/* __ret already used by WT_RET */	\
+	char *__p;							\
+									\
+	/*								\
+	 * This macro is used to both initialize and concatenate into a	\
+	 * buffer. If not concatenating, clear the size so we don't use	\
+	 * any existing contents.					\
+	 */								\
+	if (!concatenate)						\
+		(buf)->size = 0;					\
+	for (;;) {							\
+		WT_ASSERT(session, (buf)->memsize >= (buf)->size);	\
+		__p = (char *)((uint8_t *)(buf)->mem + (buf)->size);	\
+		__space = (buf)->memsize - (buf)->size;			\
+									\
+		/* Format into the buffer. */				\
+		va_start(__ap, fmt);					\
+		__ret_xx = __wt_vsnprintf_len_set(			\
+		    __p, __space, &__len, fmt, __ap);			\
+		va_end(__ap);						\
+		WT_RET(__ret_xx);					\
+									\
+		/* Check if there was enough space. */			\
+		if (__len < __space) {					\
+			(buf)->data = (buf)->mem;			\
+			(buf)->size += __len;				\
+			break;						\
+		}							\
+									\
+		/*							\
+		 * If not, double the size of the buffer: we're dealing	\
+		 * with strings, we don't expect the size to get huge.	\
+		 */							\
+		WT_RET(__wt_buf_extend(					\
+		    session, buf, (buf)->size + __len + 1));		\
+	}								\
+} while (0)
diff --git a/src/third_party/wiredtiger/src/include/misc.i b/src/third_party/wiredtiger/src/include/misc.i
index 2c380e95ade..5c9f95bc08a 100644
--- a/src/third_party/wiredtiger/src/include/misc.i
+++ b/src/third_party/wiredtiger/src/include/misc.i
@@ -259,15 +259,26 @@ __wt_spin_backoff(uint64_t *yield_count, uint64_t *sleep_usecs)
 static inline void
 __wt_timing_stress(WT_SESSION_IMPL *session, u_int flag)
 {
-	WT_CONNECTION_IMPL *conn;
-	uint64_t sleep_usecs;
+	uint64_t i;
 
-	conn = S2C(session);
-
-	/* Only sleep when the specified configuration flag is set. */
-	if (!FLD_ISSET(conn->timing_stress_flags, flag))
+	/* Optionally only sleep when a specified configuration flag is set. */
+	if (flag != 0 && !FLD_ISSET(S2C(session)->timing_stress_flags, flag))
 		return;
 
-	sleep_usecs = __wt_random(&session->rnd) % WT_TIMING_STRESS_MAX_DELAY;
-	__wt_sleep(0, sleep_usecs);
+	/*
+	 * We need a fast way to choose a sleep time. We want to sleep a short
+	 * period most of the time, but occasionally wait longer. Divide the
+	 * maximum period of time into 10 buckets (where bucket 0 doesn't sleep
+	 * at all), and roll dice, advancing to the next bucket 50% of the time.
+	 * That means we'll hit the maximum roughly every 1K calls.
+	 */
+	for (i = 0;;)
+		if (__wt_random(&session->rnd) & 0x1 || ++i > 9)
+			break;
+
+	if (i == 0)
+		__wt_yield();
+	else
+		/* The default maximum delay is 1/10th of a second. */
+		__wt_sleep(0, i * (WT_TIMING_STRESS_MAX_DELAY / 10));
 }
diff --git a/src/third_party/wiredtiger/src/include/os_fhandle.i b/src/third_party/wiredtiger/src/include/os_fhandle.i
index 7c09a83132c..78d01abca4b 100644
--- a/src/third_party/wiredtiger/src/include/os_fhandle.i
+++ b/src/third_party/wiredtiger/src/include/os_fhandle.i
@@ -72,7 +72,7 @@ __wt_fextend(WT_SESSION_IMPL *session, WT_FH *fh, wt_off_t offset)
 	if (handle->fh_extend != NULL)
 		return (handle->fh_extend(
 		    handle, (WT_SESSION *)session, offset));
-	return (ENOTSUP);
+	return (__wt_set_return(session, ENOTSUP));
 }
 
 /*
@@ -157,7 +157,7 @@ __wt_ftruncate(WT_SESSION_IMPL *session, WT_FH *fh, wt_off_t offset)
 	if (handle->fh_truncate != NULL)
 		return (handle->fh_truncate(
 		    handle, (WT_SESSION *)session, offset));
-	return (ENOTSUP);
+	return (__wt_set_return(session, ENOTSUP));
 }
 
 /*
diff --git a/src/third_party/wiredtiger/src/include/wiredtiger.in b/src/third_party/wiredtiger/src/include/wiredtiger.in
index a4ba834d5ef..2dcf65319b8 100644
--- a/src/third_party/wiredtiger/src/include/wiredtiger.in
+++ b/src/third_party/wiredtiger/src/include/wiredtiger.in
@@ -2334,15 +2334,15 @@ struct __wt_connection {
 	 * given as a list\, such as
 	 * <code>"verbose=[evictserver\,read]"</code>., a list\, with values
 	 * chosen from the following options: \c "api"\, \c "block"\, \c
-	 * "checkpoint"\, \c "checkpoint_progress"\, \c "compact"\, \c "evict"\,
-	 * \c "evict_stuck"\, \c "evictserver"\, \c "fileops"\, \c "handleops"\,
-	 * \c "log"\, \c "lookaside"\, \c "lookaside_activity"\, \c "lsm"\, \c
-	 * "lsm_manager"\, \c "metadata"\, \c "mutex"\, \c "overflow"\, \c
-	 * "read"\, \c "rebalance"\, \c "reconcile"\, \c "recovery"\, \c
-	 * "recovery_progress"\, \c "salvage"\, \c "shared_cache"\, \c "split"\,
-	 * \c "temporary"\, \c "thread_group"\, \c "timestamp"\, \c
-	 * "transaction"\, \c "verify"\, \c "version"\, \c "write"; default
-	 * empty.}
+	 * "checkpoint"\, \c "checkpoint_progress"\, \c "compact"\, \c
+	 * "error_returns"\, \c "evict"\, \c "evict_stuck"\, \c "evictserver"\,
+	 * \c "fileops"\, \c "handleops"\, \c "log"\, \c "lookaside"\, \c
+	 * "lookaside_activity"\, \c "lsm"\, \c "lsm_manager"\, \c "metadata"\,
+	 * \c "mutex"\, \c "overflow"\, \c "read"\, \c "rebalance"\, \c
+	 * "reconcile"\, \c "recovery"\, \c "recovery_progress"\, \c "salvage"\,
+	 * \c "shared_cache"\, \c "split"\, \c "temporary"\, \c "thread_group"\,
+	 * \c "timestamp"\, \c "transaction"\, \c "verify"\, \c "version"\, \c
+	 * "write"; default empty.}
 	 * @configend
 	 * @errors
 	 */
@@ -2902,9 +2902,10 @@ struct __wt_connection {
  * flag; default \c true.}
  * @config{&nbsp;&nbsp;&nbsp;&nbsp;recover, run recovery
  * or error if recovery needs to run after an unclean shutdown., a string\,
- * chosen from the following options: \c "error"\, \c "on"; default \c on.}
- * @config{&nbsp;&nbsp;&nbsp;&nbsp;zero_fill, manually write zeroes into log
- * files., a boolean flag; default \c false.}
+ * chosen from the following options: \c "error"\, \c "on"\, \c "salvage";
+ * default \c on.}
+ * @config{&nbsp;&nbsp;&nbsp;&nbsp;zero_fill, manually write
+ * zeroes into log files., a boolean flag; default \c false.}
  * @config{ ),,}
  * @config{lsm_manager = (, configure database wide options for LSM tree
  * management.  The LSM manager is started automatically the first time an LSM
@@ -3017,14 +3018,14 @@ struct __wt_connection {
  * @config{verbose, enable messages for various events.  Options are given as a
  * list\, such as <code>"verbose=[evictserver\,read]"</code>., a list\, with
  * values chosen from the following options: \c "api"\, \c "block"\, \c
- * "checkpoint"\, \c "checkpoint_progress"\, \c "compact"\, \c "evict"\, \c
- * "evict_stuck"\, \c "evictserver"\, \c "fileops"\, \c "handleops"\, \c "log"\,
- * \c "lookaside"\, \c "lookaside_activity"\, \c "lsm"\, \c "lsm_manager"\, \c
- * "metadata"\, \c "mutex"\, \c "overflow"\, \c "read"\, \c "rebalance"\, \c
- * "reconcile"\, \c "recovery"\, \c "recovery_progress"\, \c "salvage"\, \c
- * "shared_cache"\, \c "split"\, \c "temporary"\, \c "thread_group"\, \c
- * "timestamp"\, \c "transaction"\, \c "verify"\, \c "version"\, \c "write";
- * default empty.}
+ * "checkpoint"\, \c "checkpoint_progress"\, \c "compact"\, \c "error_returns"\,
+ * \c "evict"\, \c "evict_stuck"\, \c "evictserver"\, \c "fileops"\, \c
+ * "handleops"\, \c "log"\, \c "lookaside"\, \c "lookaside_activity"\, \c
+ * "lsm"\, \c "lsm_manager"\, \c "metadata"\, \c "mutex"\, \c "overflow"\, \c
+ * "read"\, \c "rebalance"\, \c "reconcile"\, \c "recovery"\, \c
+ * "recovery_progress"\, \c "salvage"\, \c "shared_cache"\, \c "split"\, \c
+ * "temporary"\, \c "thread_group"\, \c "timestamp"\, \c "transaction"\, \c
+ * "verify"\, \c "version"\, \c "write"; default empty.}
  * @config{write_through, Use \c FILE_FLAG_WRITE_THROUGH on Windows to write to
  * files.  Ignored on non-Windows systems.  Options are given as a list\, such
  * as <code>"write_through=[data]"</code>. Configuring \c write_through requires
@@ -3549,18 +3550,17 @@ struct __wt_config_parser {
  */
 
 /*!
- * Return a buffer's CRC32C checksum.
+ * Return a pointer to a function that calculates a CRC32C checksum.
  *
  * The WiredTiger library CRC32C checksum function uses hardware support where
  * available, else it falls back to a software implementation.
  *
  * @snippet ex_all.c Checksum a buffer
  *
- * @param buffer a pointer to a buffer
- * @param len the number of valid bytes in the buffer
- * @returns the buffer's CRC32C checksum
+ * @returns a pointer to a function that takes a buffer and length and returns
+ * the CRC32C checksum
  */
-uint32_t wiredtiger_checksum_crc32c(const void *buffer, size_t len)
+uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
     WT_ATTRIBUTE_LIBRARY_VISIBLE;
 
 /*! @} */
diff --git a/src/third_party/wiredtiger/src/log/log.c b/src/third_party/wiredtiger/src/log/log.c
index 6ce26e03c5d..243af64cb18 100644
--- a/src/third_party/wiredtiger/src/log/log.c
+++ b/src/third_party/wiredtiger/src/log/log.c
@@ -10,6 +10,7 @@
 
 static int __log_newfile(WT_SESSION_IMPL *, bool, bool *);
 static int __log_openfile(WT_SESSION_IMPL *, uint32_t, uint32_t, WT_FH **);
+static int __log_truncate(WT_SESSION_IMPL *, WT_LSN *, bool, bool);
 static int __log_write_internal(
 	WT_SESSION_IMPL *, WT_ITEM *, WT_LSN *, uint32_t);
 
@@ -926,7 +927,7 @@ err:	__wt_scr_free(session, &buf);
  */
 static int
 __log_open_verify(WT_SESSION_IMPL *session, uint32_t id, WT_FH **fhp,
-    WT_LSN *lsnp, uint16_t *versionp)
+    WT_LSN *lsnp, uint16_t *versionp, bool *need_salvagep)
 {
 	WT_CONNECTION_IMPL *conn;
 	WT_DECL_ITEM(buf);
@@ -937,11 +938,15 @@ __log_open_verify(WT_SESSION_IMPL *session, uint32_t id, WT_FH **fhp,
 	WT_LOG_RECORD *logrec;
 	uint32_t allocsize, rectype;
 	const uint8_t *end, *p;
+	bool need_salvage, salvage_mode;
 
 	conn = S2C(session);
+	fh = NULL;
 	log = conn->log;
+	need_salvage = false;
 	WT_RET(__wt_scr_alloc(session, 0, &buf));
-	WT_ERR(__log_openfile(session, id, 0, &fh));
+	salvage_mode = (need_salvagep != NULL &&
+	    FLD_ISSET(conn->log_flags, WT_CONN_LOG_RECOVER_SALVAGE));
 
 	if (log == NULL)
 		allocsize = WT_LOG_ALIGN;
@@ -953,17 +958,30 @@ __log_open_verify(WT_SESSION_IMPL *session, uint32_t id, WT_FH **fhp,
 	memset(buf->mem, 0, allocsize);
 
 	/*
+	 * Any operation that fails from here on out indicates corruption
+	 * that could be salvaged.
+	 */
+	need_salvage = true;
+
+	/*
 	 * Read in the log file header and verify it.
 	 */
+	WT_ERR(__log_openfile(session, id, 0, &fh));
 	WT_ERR(__wt_read(session, fh, 0, allocsize, buf->mem));
 	logrec = (WT_LOG_RECORD *)buf->mem;
 	__wt_log_record_byteswap(logrec);
 	desc = (WT_LOG_DESC *)logrec->record;
 	__wt_log_desc_byteswap(desc);
-	if (desc->log_magic != WT_LOG_MAGIC)
-		WT_PANIC_RET(session, WT_ERROR,
-		    "log file %s corrupted: Bad magic number %" PRIu32,
-		    fh->name, desc->log_magic);
+	if (desc->log_magic != WT_LOG_MAGIC) {
+		if (salvage_mode)
+			WT_ERR_MSG(session, WT_ERROR,
+			    "log file %s corrupted: Bad magic number %" PRIu32,
+			    fh->name, desc->log_magic);
+		else
+			WT_PANIC_RET(session, WT_ERROR,
+			    "log file %s corrupted: Bad magic number %" PRIu32,
+			    fh->name, desc->log_magic);
+	}
 	/*
 	 * We cannot read future log file formats.
 	 */
@@ -1043,7 +1061,14 @@ err:	__wt_scr_free(session, &buf);
 	 */
 	if (fhp != NULL && ret == 0)
 		*fhp = fh;
-	else
+	else if (ret != 0 && need_salvage && salvage_mode) {
+		/* Let the caller know this file must be salvaged. */
+		ret = 0;
+		WT_TRET(__wt_close(session, &fh));
+		if (fhp != NULL)
+			*fhp = NULL;
+		*need_salvagep = true;
+	} else
 		WT_TRET(__wt_close(session, &fh));
 
 	return (ret);
@@ -1131,7 +1156,7 @@ __log_newfile(WT_SESSION_IMPL *session, bool conn_open, bool *created)
 		WT_STAT_CONN_INCR(session, log_close_yields);
 		__wt_log_wrlsn(session, NULL);
 		if (++yield_cnt > 10000)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		__wt_yield();
 	}
 	/*
@@ -1200,7 +1225,8 @@ __log_newfile(WT_SESSION_IMPL *session, bool conn_open, bool *created)
 	 * we must pass in a local file handle.  Otherwise there is a wide
 	 * window where another thread could see a NULL log file handle.
 	 */
-	WT_RET(__log_open_verify(session, log->fileid, &log_fh, NULL, NULL));
+	WT_RET(__log_open_verify(session, log->fileid, &log_fh, NULL, NULL,
+	    NULL));
 	/*
 	 * Write the LSN at the end of the last record in the previous log file
 	 * as the first record in this log file.
@@ -1412,25 +1438,31 @@ __log_truncate_file(WT_SESSION_IMPL *session, WT_FH *log_fh, wt_off_t offset)
  *	it will truncate between the given LSN and the trunc_lsn.  That is,
  *	since we pre-allocate log files, it will free that space and allow the
  *	log to be traversed.  We use the trunc_lsn because logging has already
- *	opened the new/next log file before recovery ran.  This function assumes
- *	we are in recovery or other dedicated time and not during live running.
+ *	opened the new/next log file before recovery ran.  If salvage_mode is
+ *	set, we verify headers of log files visited and recreate them if they
+ *	are damaged.  This function assumes we are in recovery or other
+ *	dedicated time and not during live running.
  */
 static int
-__log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, bool this_log)
+__log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, bool this_log,
+    bool salvage_mode)
 {
 	WT_CONNECTION_IMPL *conn;
 	WT_DECL_RET;
 	WT_FH *log_fh;
 	WT_LOG *log;
-	uint32_t lognum;
+	uint32_t lognum, salvage_first, salvage_last;
 	u_int i, logcount;
 	char **logfiles;
+	bool need_salvage, opened;
 
 	conn = S2C(session);
 	log = conn->log;
 	log_fh = NULL;
 	logcount = 0;
 	logfiles = NULL;
+	salvage_first = salvage_last = 0;
+	need_salvage = false;
 
 	/*
 	 * Truncate the log file to the given LSN.
@@ -1446,6 +1478,10 @@ __log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, bool this_log)
 	WT_ERR(__wt_fsync(session, log_fh, true));
 	WT_ERR(__wt_close(session, &log_fh));
 
+	if (salvage_mode)
+		WT_ERR(__wt_msg(session,
+		    "salvage: log file %" PRIu32 " truncated", lsn->l.file));
+
 	/*
 	 * If we just want to truncate the current log, return and skip
 	 * looking for intervening logs.
@@ -1456,7 +1492,32 @@ __log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, bool this_log)
 	for (i = 0; i < logcount; i++) {
 		WT_ERR(__wt_log_extract_lognum(session, logfiles[i], &lognum));
 		if (lognum > lsn->l.file && lognum < log->trunc_lsn.l.file) {
-			WT_ERR(__log_openfile(session, lognum, 0, &log_fh));
+			opened = false;
+			if (salvage_mode) {
+				/*
+				 * When salvaging, we verify that the
+				 * header of the log file is valid.
+				 * If not, create a new, empty one.
+				 */
+				need_salvage = false;
+				WT_ERR(__log_open_verify(session, lognum,
+				    &log_fh, NULL, NULL, &need_salvage));
+				if (need_salvage) {
+					WT_ASSERT(session, log_fh == NULL);
+					WT_ERR(__wt_log_remove(session,
+					    WT_LOG_FILENAME, lognum));
+					WT_ERR(__wt_log_allocfile(session,
+					    lognum, WT_LOG_FILENAME));
+				} else
+					opened = true;
+
+				if (salvage_first == 0)
+					salvage_first = lognum;
+				salvage_last = lognum;
+			}
+			if (!opened)
+				WT_ERR(__log_openfile(session, lognum, 0,
+				    &log_fh));
 			/*
 			 * If there are intervening files pre-allocated,
 			 * truncate them to the end of the log file header.
@@ -1469,6 +1530,17 @@ __log_truncate(WT_SESSION_IMPL *session, WT_LSN *lsn, bool this_log)
 	}
 err:	WT_TRET(__wt_close(session, &log_fh));
 	WT_TRET(__wt_fs_directory_list_free(session, &logfiles, logcount));
+	if (salvage_first != 0) {
+		if (salvage_last > salvage_first)
+			WT_TRET(__wt_msg(session,
+			    "salvage: log files %" PRIu32 "-%" PRIu32
+			    " truncated at beginning", salvage_first,
+			    salvage_last));
+		else
+			WT_TRET(__wt_msg(session,
+			    "salvage: log file %" PRIu32
+			    " truncated at beginning", salvage_first));
+	}
 	return (ret);
 }
 
@@ -1566,13 +1638,12 @@ __wt_log_open(WT_SESSION_IMPL *session)
 	uint16_t version;
 	u_int i, logcount;
 	char **logfiles;
+	bool need_salvage;
 
 	conn = S2C(session);
 	log = conn->log;
 	logfiles = NULL;
 	logcount = 0;
-	lastlog = 0;
-	firstlog = UINT32_MAX;
 
 	/*
 	 * Open up a file handle to the log directory if we haven't.
@@ -1587,9 +1658,14 @@ __wt_log_open(WT_SESSION_IMPL *session)
 	if (!F_ISSET(conn, WT_CONN_READONLY))
 		WT_ERR(__log_prealloc_remove(session));
 
+again:
 	/*
 	 * Now look at the log files and set our LSNs.
 	 */
+	lastlog = 0;
+	firstlog = UINT32_MAX;
+	need_salvage = false;
+
 	WT_ERR(__log_get_files(session, WT_LOG_FILENAME, &logfiles, &logcount));
 	for (i = 0; i < logcount; i++) {
 		WT_ERR(__wt_log_extract_lognum(session, logfiles[i], &lognum));
@@ -1610,8 +1686,23 @@ __wt_log_open(WT_SESSION_IMPL *session)
 		 * we create a new log file so that we can detect an unsupported
 		 * version before modifying the file space.
 		 */
-		WT_ERR(__log_open_verify(session,
-		    lastlog, NULL, NULL, &version));
+		WT_ERR(__log_open_verify(session, lastlog, NULL, NULL,
+		    &version, &need_salvage));
+
+		/*
+		 * If we were asked to salvage and the last log file was
+		 * indeed corrupt, remove it and try all over again.
+		 */
+		if (need_salvage) {
+			WT_ERR(__wt_log_remove(
+			    session, WT_LOG_FILENAME, lastlog));
+			WT_ERR(__wt_msg(session,
+			    "salvage: log file %" PRIu32 " removed", lastlog));
+			WT_ERR(__wt_fs_directory_list_free(session, &logfiles,
+			    logcount));
+			logfiles = NULL;
+			goto again;
+		}
 	}
 
 	/*
@@ -1641,7 +1732,7 @@ __wt_log_open(WT_SESSION_IMPL *session)
 				 * have to close the file.
 				 */
 				WT_ERR(__log_open_verify(session,
-				    lognum, NULL, NULL, &version));
+				    lognum, NULL, NULL, &version, NULL));
 				/*
 				 * If we find any log file at the wrong version
 				 * set the flag and we're done.
@@ -1957,7 +2048,7 @@ __wt_log_scan(WT_SESSION_IMPL *session, WT_LSN *lsnp, uint32_t flags,
 	u_int i, logcount;
 	int firstrecord;
 	char **logfiles;
-	bool eol, partial_record;
+	bool eol, need_salvage, partial_record;
 
 	conn = S2C(session);
 	log = conn->log;
@@ -1966,6 +2057,7 @@ __wt_log_scan(WT_SESSION_IMPL *session, WT_LSN *lsnp, uint32_t flags,
 	logfiles = NULL;
 	eol = false;
 	firstrecord = 1;
+	need_salvage = false;
 
 	/*
 	 * If the caller did not give us a callback function there is nothing
@@ -2064,8 +2156,9 @@ __wt_log_scan(WT_SESSION_IMPL *session, WT_LSN *lsnp, uint32_t flags,
 		if (!WT_IS_INIT_LSN(lsnp))
 			start_lsn = *lsnp;
 	}
-	WT_ERR(__log_open_verify(session,
-	    start_lsn.l.file, &log_fh, &prev_lsn, NULL));
+	WT_ERR(__log_open_verify(session, start_lsn.l.file, &log_fh, &prev_lsn,
+	    NULL, &need_salvage));
+	WT_ERR_TEST(need_salvage, WT_ERROR);
 	WT_ERR(__wt_filesize(session, log_fh, &log_size));
 	rd_lsn = start_lsn;
 	if (LF_ISSET(WT_LOGSCAN_RECOVER))
@@ -2103,7 +2196,8 @@ advance:
 				__wt_verbose(session, WT_VERB_LOG,
 				    "Truncate end of log %" PRIu32 "/%" PRIu32,
 				    rd_lsn.l.file, rd_lsn.l.offset);
-				WT_ERR(__log_truncate(session, &rd_lsn, true));
+				WT_ERR(__log_truncate(session, &rd_lsn, true,
+				    false));
 			}
 			/*
 			 * If we had a partial record, we'll want to break
@@ -2128,7 +2222,9 @@ advance:
 				    " through %" PRIu32,
 				    rd_lsn.l.file, end_lsn.l.file);
 			WT_ERR(__log_open_verify(session,
-			    rd_lsn.l.file, &log_fh, &prev_lsn, &version));
+			    rd_lsn.l.file, &log_fh, &prev_lsn, &version,
+			    &need_salvage));
+			WT_ERR_TEST(need_salvage, WT_ERROR);
 			/*
 			 * Opening the log file reads with verify sets up the
 			 * previous LSN from the first record.  This detects
@@ -2161,10 +2257,15 @@ advance:
 		}
 		/*
 		 * Read the minimum allocation size a record could be.
+		 * Conditionally set the need_salvage flag so that if the
+		 * read fails, we know this is an situation we can salvage.
 		 */
 		WT_ASSERT(session, buf->memsize >= allocsize);
+		need_salvage = FLD_ISSET(conn->log_flags,
+		    WT_CONN_LOG_RECOVER_SALVAGE);
 		WT_ERR(__wt_read(session,
 		    log_fh, rd_lsn.l.offset, (size_t)allocsize, buf->mem));
+		need_salvage = false;
 		/*
 		 * See if we need to read more than the allocation size. We
 		 * expect that we rarely will have to read more. Most log
@@ -2215,7 +2316,9 @@ advance:
 			WT_STAT_CONN_INCR(session, log_scan_rereads);
 		}
 		/*
-		 * We read in the record, verify checksum.
+		 * We read in the record, verify checksum. A failed checksum
+		 * does not imply corruption, it may be the result of a
+		 * partial write.
 		 *
 		 * Handle little- and big-endian objects. Objects are written
 		 * in little-endian format: save the header checksum, and
@@ -2291,11 +2394,22 @@ advance:
 		__wt_verbose(session, WT_VERB_LOG,
 		    "End of recovery truncate end of log %" PRIu32 "/%" PRIu32,
 		    rd_lsn.l.file, rd_lsn.l.offset);
-		WT_ERR(__log_truncate(session, &rd_lsn, false));
+		WT_ERR(__log_truncate(session, &rd_lsn, false, false));
 	}
 
 err:	WT_STAT_CONN_INCR(session, log_scans);
 	/*
+	 * If we are salvaging and failed a salvageable operation, then
+	 * truncate the log at the fail point.
+	 */
+	if (ret != 0 && need_salvage) {
+		WT_TRET(__wt_close(session, &log_fh));
+		log_fh = NULL;
+		WT_TRET(__log_truncate(session, &rd_lsn, false, true));
+		ret = 0;
+	}
+
+	/*
 	 * If the first attempt to read a log record results in
 	 * an error recovery is likely going to fail.  Try to provide
 	 * a helpful failure message.
diff --git a/src/third_party/wiredtiger/src/log/log_slot.c b/src/third_party/wiredtiger/src/log/log_slot.c
index 8deda5e242f..c75181d0687 100644
--- a/src/third_party/wiredtiger/src/log/log_slot.c
+++ b/src/third_party/wiredtiger/src/log/log_slot.c
@@ -119,7 +119,7 @@ retry:
 	 * decide if retrying is necessary or not.
 	 */
 	if (forced && WT_LOG_SLOT_INPROGRESS(old_state))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 	/*
 	 * If someone else is switching out this slot we lost.  Nothing to
 	 * do but return.  Return WT_NOTFOUND anytime the given slot was
diff --git a/src/third_party/wiredtiger/src/lsm/lsm_tree.c b/src/third_party/wiredtiger/src/lsm/lsm_tree.c
index 16b28a1aecc..03feafe3c8c 100644
--- a/src/third_party/wiredtiger/src/lsm/lsm_tree.c
+++ b/src/third_party/wiredtiger/src/lsm/lsm_tree.c
@@ -419,7 +419,8 @@ __lsm_tree_find(WT_SESSION_IMPL *session,
 				 */
 				if (!__wt_atomic_cas_ptr(
 				    &lsm_tree->excl_session, NULL, session))
-					return (EBUSY);
+					return (__wt_set_return(
+					    session, EBUSY));
 
 				/*
 				 * Drain the work queue before checking for
@@ -431,7 +432,8 @@ __lsm_tree_find(WT_SESSION_IMPL *session,
 				if (lsm_tree->refcnt != 1) {
 					__wt_lsm_tree_release(
 					    session, lsm_tree);
-					return (EBUSY);
+					return (__wt_set_return(
+					    session, EBUSY));
 				}
 			} else {
 				(void)__wt_atomic_add32(&lsm_tree->refcnt, 1);
@@ -445,7 +447,8 @@ __lsm_tree_find(WT_SESSION_IMPL *session,
 					    lsm_tree->refcnt > 0);
 					__wt_lsm_tree_release(
 					    session, lsm_tree);
-					return (EBUSY);
+					return (__wt_set_return(
+					    session, EBUSY));
 				}
 			}
 
diff --git a/src/third_party/wiredtiger/src/os_common/os_abort.c b/src/third_party/wiredtiger/src/os_common/os_abort.c
index 85dcc741855..54cae3e61aa 100644
--- a/src/third_party/wiredtiger/src/os_common/os_abort.c
+++ b/src/third_party/wiredtiger/src/os_common/os_abort.c
@@ -15,6 +15,7 @@
 void
 __wt_abort(WT_SESSION_IMPL *session)
     WT_GCC_FUNC_ATTRIBUTE((noreturn))
+    WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
 #ifdef HAVE_ATTACH
 	u_int i;
diff --git a/src/third_party/wiredtiger/src/os_common/os_fs_inmemory.c b/src/third_party/wiredtiger/src/os_common/os_fs_inmemory.c
index cb7a05e05d9..182f89cc5e1 100644
--- a/src/third_party/wiredtiger/src/os_common/os_fs_inmemory.c
+++ b/src/third_party/wiredtiger/src/os_common/os_fs_inmemory.c
@@ -63,7 +63,7 @@ __im_handle_remove(WT_SESSION_IMPL *session,
 	if (im_fh->ref != 0) {
 		__wt_err(session, EBUSY, "%s: file-remove", im_fh->iface.name);
 		if (!force)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 	}
 
 	bucket = im_fh->name_hash % WT_HASH_ARRAY_SIZE;
@@ -272,7 +272,7 @@ __im_fs_size(WT_FILE_SYSTEM *file_system,
 
 	/* Search for the handle, then get its size. */
 	if ((im_fh = __im_handle_search(file_system, name)) == NULL)
-		ret = ENOENT;
+		ret = __wt_set_return(session, ENOENT);
 	else
 		*sizep = (wt_off_t)im_fh->buf.size;
 
diff --git a/src/third_party/wiredtiger/src/os_posix/os_dir.c b/src/third_party/wiredtiger/src/os_posix/os_dir.c
index 2c2cb084a91..54614d67649 100644
--- a/src/third_party/wiredtiger/src/os_posix/os_dir.c
+++ b/src/third_party/wiredtiger/src/os_posix/os_dir.c
@@ -41,11 +41,12 @@ __directory_list_worker(WT_FILE_SYSTEM *file_system,
 	 * but various static analysis programs remain unconvinced, check both.
 	 */
 	WT_SYSCALL_RETRY(((dirp = opendir(directory)) == NULL ? -1 : 0), ret);
-	if (dirp == NULL && ret == 0)
-		ret = EINVAL;
-	if (ret != 0)
+	if (dirp == NULL || ret != 0) {
+		if (ret == 0)
+			ret = EINVAL;
 		WT_RET_MSG(session, ret,
 		    "%s: directory-list: opendir", directory);
+	}
 
 	for (count = 0; (dp = readdir(dirp)) != NULL;) {
 		/*
diff --git a/src/third_party/wiredtiger/src/os_posix/os_fallocate.c b/src/third_party/wiredtiger/src/os_posix/os_fallocate.c
index 6f6e6a6bdc2..cde6adfe780 100644
--- a/src/third_party/wiredtiger/src/os_posix/os_fallocate.c
+++ b/src/third_party/wiredtiger/src/os_posix/os_fallocate.c
@@ -33,9 +33,9 @@ __posix_std_fallocate(
 	return (ret);
 #else
 	WT_UNUSED(file_handle);
-	WT_UNUSED(wt_session);
 	WT_UNUSED(offset);
-	return (ENOTSUP);
+
+	return (__wt_set_return((WT_SESSION_IMPL *)wt_session, ENOTSUP));
 #endif
 }
 
@@ -66,9 +66,9 @@ __posix_sys_fallocate(
 	return (ret);
 #else
 	WT_UNUSED(file_handle);
-	WT_UNUSED(wt_session);
 	WT_UNUSED(offset);
-	return (ENOTSUP);
+
+	return (__wt_set_return((WT_SESSION_IMPL *)wt_session, ENOTSUP));
 #endif
 }
 
@@ -92,9 +92,9 @@ __posix_posix_fallocate(
 	return (ret);
 #else
 	WT_UNUSED(file_handle);
-	WT_UNUSED(wt_session);
 	WT_UNUSED(offset);
-	return (ENOTSUP);
+
+	return (__wt_set_return((WT_SESSION_IMPL *)wt_session, ENOTSUP));
 #endif
 }
 
diff --git a/src/third_party/wiredtiger/src/os_posix/os_fs.c b/src/third_party/wiredtiger/src/os_posix/os_fs.c
index 0af67ad38c5..42e6e411440 100644
--- a/src/third_party/wiredtiger/src/os_posix/os_fs.c
+++ b/src/third_party/wiredtiger/src/os_posix/os_fs.c
@@ -338,7 +338,7 @@ __posix_file_advise(WT_FILE_HANDLE *file_handle, WT_SESSION *wt_session,
 	 */
 	if (ret == EINVAL) {
 		file_handle->fh_advise = NULL;
-		return (ENOTSUP);
+		return (__wt_set_return(session, ENOTSUP));
 	}
 
 	WT_RET_MSG(session, ret,
diff --git a/src/third_party/wiredtiger/src/os_posix/os_map.c b/src/third_party/wiredtiger/src/os_posix/os_map.c
index b9ec284e124..f04a966c468 100644
--- a/src/third_party/wiredtiger/src/os_posix/os_map.c
+++ b/src/third_party/wiredtiger/src/os_posix/os_map.c
@@ -33,7 +33,7 @@ __wt_posix_map(WT_FILE_HANDLE *fh, WT_SESSION *wt_session,
 	 * mmap(2) of files with direct I/O to the same files.
 	 */
 	if (pfh->direct_io)
-		return (ENOTSUP);
+		return (__wt_set_return(session, ENOTSUP));
 
 	/*
 	 * There's no locking here to prevent the underlying file from changing
diff --git a/src/third_party/wiredtiger/src/os_win/os_fs.c b/src/third_party/wiredtiger/src/os_win/os_fs.c
index 66f4de87299..c75e8365116 100644
--- a/src/third_party/wiredtiger/src/os_win/os_fs.c
+++ b/src/third_party/wiredtiger/src/os_win/os_fs.c
@@ -393,7 +393,7 @@ __win_file_set_end(
 
 	if (SetEndOfFile(win_fh->filehandle_secondary) == FALSE) {
 		if (GetLastError() == ERROR_USER_MAPPED_FILE)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		windows_error = __wt_getlasterror();
 		ret = __wt_map_windows_error(windows_error);
 		__wt_err(session, ret,
diff --git a/src/third_party/wiredtiger/src/reconcile/rec_write.c b/src/third_party/wiredtiger/src/reconcile/rec_write.c
index 2ec28e31201..7faf19734a5 100644
--- a/src/third_party/wiredtiger/src/reconcile/rec_write.c
+++ b/src/third_party/wiredtiger/src/reconcile/rec_write.c
@@ -420,7 +420,7 @@ __wt_reconcile(WT_SESSION_IMPL *session, WT_REF *ref,
 	if (LF_ISSET(WT_REC_EVICT) &&
 	    !__wt_page_can_evict(session, ref, NULL)) {
 		WT_PAGE_UNLOCK(session, page);
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 	}
 
 	/* Initialize the reconciliation structure for each new run. */
@@ -442,8 +442,9 @@ __wt_reconcile(WT_SESSION_IMPL *session, WT_REF *ref,
 	if (LF_ISSET(WT_REC_EVICT)) {
 		mod->last_eviction_id = oldest_id;
 #ifdef HAVE_TIMESTAMPS
-		__wt_txn_pinned_timestamp(
-		    session, &mod->last_eviction_timestamp);
+		if (S2C(session)->txn_global.has_pinned_timestamp)
+			__wt_txn_pinned_timestamp(
+			    session, &mod->last_eviction_timestamp);
 #endif
 		mod->last_evict_pass_gen = S2C(session)->cache->evict_pass_gen;
 	}
@@ -651,7 +652,7 @@ __rec_write_check_complete(
 		return (0);
 
 	*lookaside_retryp = true;
-	return (EBUSY);
+	return (__wt_set_return(session, EBUSY));
 }
 
 /*
@@ -1397,7 +1398,7 @@ __rec_txn_read(WT_SESSION_IMPL *session, WT_RECONCILE *r,
 			if (F_ISSET(r, WT_REC_UPDATE_RESTORE) &&
 			    *updp != NULL && uncommitted) {
 				r->leave_dirty = true;
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 			}
 
 			if (upd->type == WT_UPDATE_BIRTHMARK)
@@ -1517,9 +1518,9 @@ __rec_txn_read(WT_SESSION_IMPL *session, WT_RECONCILE *r,
 	 * the WT_REC_LOOKASIDE flag.
 	 */
 	if (!F_ISSET(r, WT_REC_LOOKASIDE | WT_REC_UPDATE_RESTORE))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 	if (uncommitted && !F_ISSET(r, WT_REC_UPDATE_RESTORE))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	WT_ASSERT(session, r->max_txn != WT_TXN_NONE);
 
@@ -1704,7 +1705,7 @@ __rec_child_deleted(WT_SESSION_IMPL *session,
 	 * the original page and which should see the deleted page).
 	 */
 	if (F_ISSET(r, WT_REC_EVICT))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * If there are deleted child pages we can't discard immediately, keep
@@ -1789,7 +1790,7 @@ __rec_child_modify(WT_SESSION_IMPL *session,
 			 */
 			WT_ASSERT(session, !F_ISSET(r, WT_REC_EVICT));
 			if (F_ISSET(r, WT_REC_EVICT))
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 
 			/*
 			 * If called during checkpoint, the child is being
@@ -1817,7 +1818,7 @@ __rec_child_modify(WT_SESSION_IMPL *session,
 			if (F_ISSET(r, WT_REC_EVICT) &&
 			    __wt_page_las_active(session, ref)) {
 				WT_ASSERT(session, false);
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 			}
 
 			/*
@@ -1842,7 +1843,7 @@ __rec_child_modify(WT_SESSION_IMPL *session,
 			 */
 			WT_ASSERT(session, !F_ISSET(r, WT_REC_EVICT));
 			if (F_ISSET(r, WT_REC_EVICT))
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 
 			/*
 			 * If called during checkpoint, acquire a hazard pointer
@@ -1877,7 +1878,7 @@ __rec_child_modify(WT_SESSION_IMPL *session,
 			 */
 			WT_ASSERT(session, !F_ISSET(r, WT_REC_EVICT));
 			if (F_ISSET(r, WT_REC_EVICT))
-				return (EBUSY);
+				return (__wt_set_return(session, EBUSY));
 			goto done;
 
 		case WT_REF_SPLIT:
@@ -1894,7 +1895,7 @@ __rec_child_modify(WT_SESSION_IMPL *session,
 			 * for checkpoint.
 			 */
 			WT_ASSERT(session, WT_REF_SPLIT != WT_REF_SPLIT);
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 
 		WT_ILLEGAL_VALUE(session);
 		}
@@ -3704,7 +3705,7 @@ __rec_split_write(WT_SESSION_IMPL *session, WT_RECONCILE *r,
 		 * allocate a zero-length array.
 		 */
 		if (r->page->type != WT_PAGE_ROW_LEAF && chunk->entries == 0)
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 
 		if (F_ISSET(r, WT_REC_LOOKASIDE)) {
 			r->cache_write_lookaside = true;
diff --git a/src/third_party/wiredtiger/src/schema/schema_alter.c b/src/third_party/wiredtiger/src/schema/schema_alter.c
index e880cb415c8..aba708f0e0b 100644
--- a/src/third_party/wiredtiger/src/schema/schema_alter.c
+++ b/src/third_party/wiredtiger/src/schema/schema_alter.c
@@ -53,7 +53,7 @@ err:	__wt_free(session, config);
 	 * there was no metadata entry.
 	 */
 	if (ret == WT_NOTFOUND)
-		ret = ENOENT;
+		ret = __wt_set_return(session, ENOENT);
 
 	return (ret);
 }
diff --git a/src/third_party/wiredtiger/src/schema/schema_list.c b/src/third_party/wiredtiger/src/schema/schema_list.c
index 0f8806dd462..990f2636bf9 100644
--- a/src/third_party/wiredtiger/src/schema/schema_list.c
+++ b/src/third_party/wiredtiger/src/schema/schema_list.c
@@ -28,7 +28,7 @@ __wt_schema_get_table_uri(WT_SESSION_IMPL *session,
 	WT_ERR(__wt_session_get_dhandle(session, uri, NULL, NULL, flags));
 	table = (WT_TABLE *)session->dhandle;
 	if (!ok_incomplete && !table->cg_complete) {
-		ret = EINVAL;
+		ret = __wt_set_return(session, EINVAL);
 		WT_TRET(__wt_session_release_dhandle(session));
 		WT_ERR_MSG(session, ret, "'%s' cannot be used "
 		    "until all column groups are created",
diff --git a/src/third_party/wiredtiger/src/schema/schema_plan.c b/src/third_party/wiredtiger/src/schema/schema_plan.c
index abe76013e12..7fb2a391784 100644
--- a/src/third_party/wiredtiger/src/schema/schema_plan.c
+++ b/src/third_party/wiredtiger/src/schema/schema_plan.c
@@ -298,7 +298,7 @@ __find_column_format(WT_SESSION_IMPL *session, WT_TABLE *table,
 		if (k.len == colname->len &&
 		    strncmp(colname->str, k.str, k.len) == 0) {
 			if (value_only && inkey)
-				return (EINVAL);
+				return (__wt_set_return(session, EINVAL));
 			return (0);
 		}
 	}
diff --git a/src/third_party/wiredtiger/src/schema/schema_util.c b/src/third_party/wiredtiger/src/schema/schema_util.c
index ceec6db6cb5..a281ec3fe12 100644
--- a/src/third_party/wiredtiger/src/schema/schema_util.c
+++ b/src/third_party/wiredtiger/src/schema/schema_util.c
@@ -39,7 +39,7 @@ __wt_schema_backup_check(WT_SESSION_IMPL *session, const char *name)
 	}
 	for (i = 0; backup_list[i] != NULL; ++i) {
 		if (strcmp(backup_list[i], name) == 0) {
-			ret = EBUSY;
+			ret = __wt_set_return(session, EBUSY);
 			break;
 		}
 	}
diff --git a/src/third_party/wiredtiger/src/session/session_dhandle.c b/src/third_party/wiredtiger/src/session/session_dhandle.c
index caa775686cf..30399cafd22 100644
--- a/src/third_party/wiredtiger/src/session/session_dhandle.c
+++ b/src/third_party/wiredtiger/src/session/session_dhandle.c
@@ -140,7 +140,7 @@ __wt_session_lock_dhandle(
 		if (!LF_ISSET(WT_DHANDLE_LOCK_ONLY) &&
 		    (!F_ISSET(dhandle, WT_DHANDLE_OPEN) ||
 		    (btree != NULL && F_ISSET(btree, WT_BTREE_SPECIAL_FLAGS))))
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 		++dhandle->excl_ref;
 		return (0);
 	}
@@ -167,7 +167,7 @@ __wt_session_lock_dhandle(
 		 * give up.
 		 */
 		if (btree != NULL && F_ISSET(btree, WT_BTREE_SPECIAL_FLAGS))
-			return (EBUSY);
+			return (__wt_set_return(session, EBUSY));
 
 		/*
 		 * If the handle is open, get a read lock and recheck.
diff --git a/src/third_party/wiredtiger/src/support/err.c b/src/third_party/wiredtiger/src/support/err.c
index 0569d0545e6..6010b310ba1 100644
--- a/src/third_party/wiredtiger/src/support/err.c
+++ b/src/third_party/wiredtiger/src/support/err.c
@@ -174,7 +174,7 @@ __wt_event_handler_set(WT_SESSION_IMPL *session, WT_EVENT_HANDLER *handler)
  */
 static int
 __eventv(WT_SESSION_IMPL *session, bool msg_event, int error,
-    const char *file_name, int line_number, const char *fmt, va_list ap)
+    const char *func_name, int line_number, const char *fmt, va_list ap)
     WT_GCC_FUNC_ATTRIBUTE((cold))
 {
 	struct timespec ts;
@@ -231,8 +231,8 @@ __eventv(WT_SESSION_IMPL *session, bool msg_event, int error,
 		WT_ERROR_APPEND(p, remain, ", %s", prefix);
 	WT_ERROR_APPEND(p, remain, ": ");
 
-	if (file_name != NULL)
-		WT_ERROR_APPEND(p, remain, "%s, %d: ", file_name, line_number);
+	if (func_name != NULL)
+		WT_ERROR_APPEND(p, remain, "%s, %d: ", func_name, line_number);
 
 	WT_ERROR_APPEND_AP(p, remain, fmt, ap);
 
@@ -309,13 +309,14 @@ err:		if (fprintf(stderr,
 }
 
 /*
- * __wt_err --
+ * __wt_err_func --
  * 	Report an error.
  */
 void
-__wt_err(WT_SESSION_IMPL *session, int error, const char *fmt, ...)
+__wt_err_func(WT_SESSION_IMPL *session,
+    int error, const char *func_name, int line_number, const char *fmt, ...)
     WT_GCC_FUNC_ATTRIBUTE((cold))
-    WT_GCC_FUNC_ATTRIBUTE((format (printf, 3, 4)))
+    WT_GCC_FUNC_ATTRIBUTE((format (printf, 5, 6)))
     WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
 	va_list ap;
@@ -325,18 +326,21 @@ __wt_err(WT_SESSION_IMPL *session, int error, const char *fmt, ...)
 	 * an error value to return.
 	 */
 	va_start(ap, fmt);
-	WT_IGNORE_RET(__eventv(session, false, error, NULL, 0, fmt, ap));
+	WT_IGNORE_RET(__eventv(session,
+	    false, error, func_name, line_number, fmt, ap));
 	va_end(ap);
 }
 
 /*
- * __wt_errx --
+ * __wt_errx_func --
  * 	Report an error with no error code.
  */
 void
-__wt_errx(WT_SESSION_IMPL *session, const char *fmt, ...)
+__wt_errx_func(WT_SESSION_IMPL *session,
+    const char *func_name, int line_number, const char *fmt, ...)
     WT_GCC_FUNC_ATTRIBUTE((cold))
-    WT_GCC_FUNC_ATTRIBUTE((format (printf, 2, 3)))
+    WT_GCC_FUNC_ATTRIBUTE((format (printf, 4, 5)))
+    WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
 	va_list ap;
 
@@ -345,11 +349,25 @@ __wt_errx(WT_SESSION_IMPL *session, const char *fmt, ...)
 	 * an error value to return.
 	 */
 	va_start(ap, fmt);
-	WT_IGNORE_RET(__eventv(session, false, 0, NULL, 0, fmt, ap));
+	WT_IGNORE_RET(__eventv(session,
+	    false, 0, func_name, line_number, fmt, ap));
 	va_end(ap);
 }
 
 /*
+ * __wt_set_return_func --
+ * 	Conditionally log the source of an error code and return the error.
+ */
+int
+__wt_set_return_func(
+    WT_SESSION_IMPL *session, const char* func, int line, int err)
+{
+	__wt_verbose(session,
+	    WT_VERB_ERROR_RETURNS, "%s: %d Error: %d", func, line, err);
+	return (err);
+}
+
+/*
  * __wt_ext_err_printf --
  *	Extension API call to print to the error stream.
  */
@@ -388,44 +406,28 @@ __wt_verbose_worker(WT_SESSION_IMPL *session, const char *fmt, ...)
 }
 
 /*
- * info_msg --
+ * __wt_msg --
  * 	Informational message.
  */
-static int
-info_msg(WT_SESSION_IMPL *session, const char *fmt, va_list ap)
+int
+__wt_msg(WT_SESSION_IMPL *session, const char *fmt, ...)
+    WT_GCC_FUNC_ATTRIBUTE((cold))
+    WT_GCC_FUNC_ATTRIBUTE((format (printf, 2, 3)))
 {
+	WT_DECL_ITEM(buf);
+	WT_DECL_RET;
 	WT_EVENT_HANDLER *handler;
 	WT_SESSION *wt_session;
 
-	/*
-	 * !!!
-	 * SECURITY:
-	 * Buffer placed at the end of the stack in case snprintf overflows.
-	 */
-	char s[2048];
+	WT_RET(__wt_scr_alloc(session, 0, &buf));
 
-	WT_RET(__wt_vsnprintf(s, sizeof(s), fmt, ap));
+	WT_VA_ARGS_BUF_FORMAT(session, buf, fmt, false);
 
 	wt_session = (WT_SESSION *)session;
 	handler = session->event_handler;
-	return (handler->handle_message(handler, wt_session, s));
-}
+	ret = handler->handle_message(handler, wt_session, buf->data);
 
-/*
- * __wt_msg --
- * 	Informational message.
- */
-int
-__wt_msg(WT_SESSION_IMPL *session, const char *fmt, ...)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
-    WT_GCC_FUNC_ATTRIBUTE((format (printf, 2, 3)))
-{
-	WT_DECL_RET;
-	va_list ap;
-
-	va_start(ap, fmt);
-	ret = info_msg(session, fmt, ap);
-	va_end(ap);
+	__wt_scr_free(session, &buf);
 
 	return (ret);
 }
@@ -439,16 +441,24 @@ __wt_ext_msg_printf(
     WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, const char *fmt, ...)
     WT_GCC_FUNC_ATTRIBUTE((format (printf, 3, 4)))
 {
+	WT_DECL_ITEM(buf);
 	WT_DECL_RET;
+	WT_EVENT_HANDLER *handler;
 	WT_SESSION_IMPL *session;
-	va_list ap;
 
 	if ((session = (WT_SESSION_IMPL *)wt_session) == NULL)
 		session = ((WT_CONNECTION_IMPL *)wt_api->conn)->default_session;
 
-	va_start(ap, fmt);
-	ret = info_msg(session, fmt, ap);
-	va_end(ap);
+	WT_RET(__wt_scr_alloc(session, 0, &buf));
+
+	WT_VA_ARGS_BUF_FORMAT(session, buf, fmt, false);
+
+	wt_session = (WT_SESSION *)session;
+	handler = session->event_handler;
+	ret = handler->handle_message(handler, wt_session, buf->data);
+
+	__wt_scr_free(session, &buf);
+
 	return (ret);
 }
 
@@ -487,34 +497,6 @@ __wt_progress(WT_SESSION_IMPL *session, const char *s, uint64_t v)
 }
 
 /*
- * __wt_assert --
- *	Assert and other unexpected failures, includes file/line information
- * for debugging.
- */
-void
-__wt_assert(WT_SESSION_IMPL *session,
-    int error, const char *file_name, int line_number, const char *fmt, ...)
-    WT_GCC_FUNC_ATTRIBUTE((cold))
-    WT_GCC_FUNC_ATTRIBUTE((format (printf, 5, 6)))
-#ifdef HAVE_DIAGNOSTIC
-    WT_GCC_FUNC_ATTRIBUTE((noreturn))
-#endif
-    WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
-{
-	va_list ap;
-
-	va_start(ap, fmt);
-	WT_IGNORE_RET(__eventv(
-	    session, false, error, file_name, line_number, fmt, ap));
-	va_end(ap);
-
-#ifdef HAVE_DIAGNOSTIC
-	__wt_abort(session);			/* Drop core if testing. */
-	/* NOTREACHED */
-#endif
-}
-
-/*
  * __wt_panic --
  *	A standard error message when we panic.
  */
diff --git a/src/third_party/wiredtiger/src/support/global.c b/src/third_party/wiredtiger/src/support/global.c
index d1271e0d427..f71f91a4daa 100644
--- a/src/third_party/wiredtiger/src/support/global.c
+++ b/src/third_party/wiredtiger/src/support/global.c
@@ -117,7 +117,7 @@ __wt_global_once(void)
 		return;
 	}
 
-	__wt_checksum_init();
+	__wt_process.checksum = wiredtiger_crc32c_func();
 	__global_calibrate_ticks();
 
 	TAILQ_INIT(&__wt_process.connqh);
diff --git a/src/third_party/wiredtiger/src/support/hazard.c b/src/third_party/wiredtiger/src/support/hazard.c
index 815c876f444..4116638e31c 100644
--- a/src/third_party/wiredtiger/src/support/hazard.c
+++ b/src/third_party/wiredtiger/src/support/hazard.c
@@ -401,6 +401,29 @@ __wt_hazard_count(WT_SESSION_IMPL *session, WT_REF *ref)
 
 #ifdef HAVE_DIAGNOSTIC
 /*
+ * __wt_hazard_check_assert --
+ *	Assert there's no hazard pointer to the page.
+ */
+bool
+__wt_hazard_check_assert(WT_SESSION_IMPL *session, void *ref, bool waitfor)
+{
+	WT_HAZARD *hp;
+	int i;
+
+	for (i = 0;;) {
+		if ((hp = __wt_hazard_check(session, ref)) == NULL)
+			return (true);
+		if (!waitfor || ++i > 100)
+			break;
+		__wt_sleep(0, 10000);
+	}
+	__wt_errx(session,
+	    "hazard pointer reference to discarded object: (%p: %s, line %d)",
+	    (void *)hp->ref, hp->file, hp->line);
+	return (false);
+}
+
+/*
  * __hazard_dump --
  *	Display the list of hazard pointers.
  */
diff --git a/src/third_party/wiredtiger/src/support/mtx_rw.c b/src/third_party/wiredtiger/src/support/mtx_rw.c
index fd66a1a40bb..959405dee50 100644
--- a/src/third_party/wiredtiger/src/support/mtx_rw.c
+++ b/src/third_party/wiredtiger/src/support/mtx_rw.c
@@ -137,7 +137,7 @@ __wt_try_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *l)
 
 	/* This read lock can only be granted if there are no active writers. */
 	if (old.u.s.current != old.u.s.next)
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * The replacement lock value is a result of adding an active reader.
@@ -146,7 +146,7 @@ __wt_try_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *l)
 	 */
 	new.u.v = old.u.v;
 	if (++new.u.s.readers_active == 0)
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/* We rely on this atomic operation to provide a barrier. */
 	return (__wt_atomic_casv64(&l->u.v, old.u.v, new.u.v) ? 0 : EBUSY);
@@ -331,7 +331,7 @@ __wt_try_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *l)
 	 */
 	old.u.v = l->u.v;
 	if (old.u.s.current != old.u.s.next || old.u.s.readers_active != 0)
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * We've checked above that there is no writer active (since
diff --git a/src/third_party/wiredtiger/src/support/scratch.c b/src/third_party/wiredtiger/src/support/scratch.c
index 2ead79a1c1c..72e312da325 100644
--- a/src/third_party/wiredtiger/src/support/scratch.c
+++ b/src/third_party/wiredtiger/src/support/scratch.c
@@ -71,30 +71,9 @@ __wt_buf_fmt(WT_SESSION_IMPL *session, WT_ITEM *buf, const char *fmt, ...)
     WT_GCC_FUNC_ATTRIBUTE((format (printf, 3, 4)))
     WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
-	WT_DECL_RET;
-	size_t len;
-	va_list ap;
-
-	for (;;) {
-		va_start(ap, fmt);
-		ret = __wt_vsnprintf_len_set(
-		    buf->mem, buf->memsize, &len, fmt, ap);
-		va_end(ap);
-		WT_RET(ret);
-
-		/* Check if there was enough space. */
-		if (len < buf->memsize) {
-			buf->data = buf->mem;
-			buf->size = len;
-			return (0);
-		}
+	WT_VA_ARGS_BUF_FORMAT(session, buf, fmt, false);
 
-		/*
-		 * If not, double the size of the buffer: we're dealing with
-		 * strings, and we don't expect these numbers to get huge.
-		 */
-		WT_RET(__wt_buf_extend(session, buf, len + 1));
-	}
+	return (0);
 }
 
 /*
@@ -106,11 +85,6 @@ __wt_buf_catfmt(WT_SESSION_IMPL *session, WT_ITEM *buf, const char *fmt, ...)
     WT_GCC_FUNC_ATTRIBUTE((format (printf, 3, 4)))
     WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
 {
-	WT_DECL_RET;
-	size_t len, space;
-	char *p;
-	va_list ap;
-
 	/*
 	 * If we're appending data to an existing buffer, any data field should
 	 * point into the allocated memory.  (It wouldn't be insane to copy any
@@ -119,27 +93,9 @@ __wt_buf_catfmt(WT_SESSION_IMPL *session, WT_ITEM *buf, const char *fmt, ...)
 	 */
 	WT_ASSERT(session, buf->data == NULL || WT_DATA_IN_ITEM(buf));
 
-	for (;;) {
-		va_start(ap, fmt);
-		p = (char *)((uint8_t *)buf->mem + buf->size);
-		WT_ASSERT(session, buf->memsize >= buf->size);
-		space = buf->memsize - buf->size;
-		ret = __wt_vsnprintf_len_set(p, space, &len, fmt, ap);
-		va_end(ap);
-		WT_RET(ret);
-
-		/* Check if there was enough space. */
-		if (len < space) {
-			buf->size += len;
-			return (0);
-		}
+	WT_VA_ARGS_BUF_FORMAT(session, buf, fmt, true);
 
-		/*
-		 * If not, double the size of the buffer: we're dealing with
-		 * strings, and we don't expect these numbers to get huge.
-		 */
-		WT_RET(__wt_buf_extend(session, buf, buf->size + len + 1));
-	}
+	return (0);
 }
 
 /*
@@ -400,16 +356,19 @@ __wt_scr_discard(WT_SESSION_IMPL *session)
 		if (*bufp == NULL)
 			continue;
 		if (F_ISSET(*bufp, WT_ITEM_INUSE))
+#ifdef HAVE_DIAGNOSTIC
 			__wt_errx(session,
 			    "scratch buffer allocated and never discarded"
-#ifdef HAVE_DIAGNOSTIC
 			    ": %s: %d",
 			    session->
 			    scratch_track[bufp - session->scratch].file,
 			    session->
 			    scratch_track[bufp - session->scratch].line
-#endif
 			    );
+#else
+			__wt_errx(session,
+			    "scratch buffer allocated and never discarded");
+#endif
 
 		__wt_buf_free(session, *bufp);
 		__wt_free(session, *bufp);
diff --git a/src/third_party/wiredtiger/src/txn/txn_ckpt.c b/src/third_party/wiredtiger/src/txn/txn_ckpt.c
index ad8351923a0..59d9fa2e7c1 100644
--- a/src/third_party/wiredtiger/src/txn/txn_ckpt.c
+++ b/src/third_party/wiredtiger/src/txn/txn_ckpt.c
@@ -1896,7 +1896,7 @@ __wt_checkpoint_close(WT_SESSION_IMPL *session, bool final)
 	if (btree->modified && !bulk &&
 	    S2C(session)->txn_global.has_stable_timestamp &&
 	    !__wt_btree_immediately_durable(session))
-		return (EBUSY);
+		return (__wt_set_return(session, EBUSY));
 
 	/*
 	 * Turn on metadata tracking if:
diff --git a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
index e01db53fda9..ba00198adbe 100644
--- a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
+++ b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
@@ -466,7 +466,8 @@ __wt_txn_rollback_to_stable(WT_SESSION_IMPL *session, const char *cfg[])
 	 * trees in cache populates a list that is used to check which
 	 * lookaside records should be removed.
 	 */
-	WT_ERR(__txn_rollback_to_stable_lookaside_fixup(session));
+	if (!F_ISSET(conn, WT_CONN_IN_MEMORY))
+		WT_ERR(__txn_rollback_to_stable_lookaside_fixup(session));
 
 err:	F_CLR(conn, WT_CONN_EVICTION_NO_LOOKASIDE);
 	__wt_free(session, conn->stable_rollback_bitstring);
diff --git a/src/third_party/wiredtiger/src/utilities/util_main.c b/src/third_party/wiredtiger/src/utilities/util_main.c
index 2d08c4c5274..7042736e2a2 100644
--- a/src/third_party/wiredtiger/src/utilities/util_main.c
+++ b/src/third_party/wiredtiger/src/utilities/util_main.c
@@ -11,7 +11,7 @@
 const char *home = ".";				/* Home directory */
 const char *progname;				/* Program name */
 						/* Global arguments */
-const char *usage_prefix = "[-LRVv] [-C config] [-E secretkey] [-h home]";
+const char *usage_prefix = "[-LRSVv] [-C config] [-E secretkey] [-h home]";
 bool verbose = false;				/* Verbose flag */
 
 static const char *command;			/* Command name */
@@ -19,6 +19,7 @@ static const char *command;			/* Command name */
 #define	REC_ERROR	"log=(recover=error)"
 #define	REC_LOGOFF	"log=(enabled=false)"
 #define	REC_RECOVER	"log=(recover=on)"
+#define	REC_SALVAGE	"log=(recover=salvage)"
 
 static void
 usage(void)
@@ -70,7 +71,7 @@ main(int argc, char *argv[])
 	int ch, major_v, minor_v, tret, (*func)(WT_SESSION *, int, char *[]);
 	const char *cmd_config, *config, *p1, *p2, *p3, *rec_config;
 	char *p, *secretkey;
-	bool logoff, needconn, recover;
+	bool logoff, needconn, recover, salvage;
 
 	conn = NULL;
 	p = NULL;
@@ -105,9 +106,9 @@ main(int argc, char *argv[])
 	 * needed, the user can specify -R to run recovery.
 	 */
 	rec_config = REC_ERROR;
-	logoff = recover = false;
+	logoff = recover = salvage = false;
 	/* Check for standard options. */
-	while ((ch = __wt_getopt(progname, argc, argv, "C:E:h:LRVv")) != EOF)
+	while ((ch = __wt_getopt(progname, argc, argv, "C:E:h:LRSVv")) != EOF)
 		switch (ch) {
 		case 'C':			/* wiredtiger_open config */
 			cmd_config = __wt_optarg;
@@ -131,6 +132,10 @@ main(int argc, char *argv[])
 			rec_config = REC_RECOVER;
 			recover = true;
 			break;
+		case 'S':			/* salvage */
+			rec_config = REC_SALVAGE;
+			salvage = true;
+			break;
 		case 'V':			/* version */
 			printf("%s\n", wiredtiger_version(NULL, NULL, NULL));
 			goto done;
@@ -142,8 +147,9 @@ main(int argc, char *argv[])
 			usage();
 			goto err;
 		}
-	if (logoff && recover) {
-		fprintf(stderr, "Only one of -L and -R is allowed.\n");
+	if ((logoff && recover) || (logoff && salvage) ||
+	    (recover && salvage)) {
+		fprintf(stderr, "Only one of -L, -R, and -S is allowed.\n");
 		goto err;
 	}
 	argc -= __wt_optind;
diff --git a/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c b/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
index 8a1781eae45..11cabf4e9db 100644
--- a/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
+++ b/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
@@ -210,7 +210,7 @@ thread_ckpt_run(void *arg)
 		    session, "use_timestamp=true"));
 		testutil_check(td->conn->query_timestamp(
 		    td->conn, buf, "get=last_checkpoint"));
-		sscanf(buf, "%" SCNx64, &stable);
+		testutil_assert(sscanf(buf, "%" SCNx64, &stable) == 1);
 		printf("Checkpoint %d complete at stable %"
 		    PRIu64 ".\n", i, stable);
 		fflush(stdout);
@@ -728,7 +728,7 @@ main(int argc, char *argv[])
 	if (use_ts) {
 		testutil_check(
 		    conn->query_timestamp(conn, buf, "get=recovery"));
-		sscanf(buf, "%" SCNx64, &stable_val);
+		testutil_assert(sscanf(buf, "%" SCNx64, &stable_val) == 1);
 		printf("Got stable_val %" PRIu64 "\n", stable_val);
 	}
 
diff --git a/src/third_party/wiredtiger/test/csuite/wt4117_checksum/main.c b/src/third_party/wiredtiger/test/csuite/wt4117_checksum/main.c
index 9a786e5d222..fff7b55bbf9 100644
--- a/src/third_party/wiredtiger/test/csuite/wt4117_checksum/main.c
+++ b/src/third_party/wiredtiger/test/csuite/wt4117_checksum/main.c
@@ -44,65 +44,51 @@ static void
 run(void)
 {
 	size_t len;
-	uint32_t crc32c;
+	uint32_t crc32c, (*func)(const void *, size_t);
 	uint8_t *data;
 
 	/* Allocate aligned memory for the data. */
 	data = dcalloc(100, sizeof(uint8_t));
 
+	/* Get a pointer to the CRC32C function. */
+	func = wiredtiger_crc32c_func();
+
 	/*
 	 * Some simple known checksums.
 	 */
 	len = 1;
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0x527d5351, len, "nul x1");
 
 	len = 2;
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0xf16177d2, len, "nul x2");
 
 	len = 3;
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0x6064a37a, len, "nul x3");
 
 	len = 4;
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0x48674bc7, len, "nul x4");
 
 	len = strlen("123456789");
 	memcpy(data, "123456789", len);
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0xe3069283, len, "known string #1");
 
 	len = strlen("The quick brown fox jumps over the lazy dog");
 	memcpy(data, "The quick brown fox jumps over the lazy dog", len);
-	crc32c = wiredtiger_checksum_crc32c(data, len);
+	crc32c = func(data, len);
 	check(crc32c, (uint32_t)0x22620404, len, "known string #2");
 
 	free(data);
 }
 
 int
-main(int argc, char *argv[])
+main(void)
 {
-	TEST_OPTS *opts, _opts;
-
-	opts = &_opts;
-	memset(opts, 0, sizeof(*opts));
-	testutil_check(testutil_parse_opts(argc, argv, opts));
-	testutil_make_work_dir(opts->home);
-
-	/*
-	 * The external API should work before the library configures itself,
-	 * run before and after calling wiredtiger_open().
-	 */
-	run();
-
-	testutil_check(
-	    wiredtiger_open(opts->home, NULL, "create", &opts->conn));
-
 	run();
 
-	testutil_cleanup(opts);
 	return (EXIT_SUCCESS);
 }
diff --git a/src/third_party/wiredtiger/test/format/config.h b/src/third_party/wiredtiger/test/format/config.h
index c398c1a96b2..70e8165e97d 100644
--- a/src/third_party/wiredtiger/test/format/config.h
+++ b/src/third_party/wiredtiger/test/format/config.h
@@ -370,10 +370,6 @@ static CONFIG c[] = {
 	  "stress splits (#8)",					/* 2% */
 	  C_BOOL, 2, 0, 0, &g.c_timing_stress_split_8, NULL },
 
-	{ "timing_stress_split_9",
-	  "stress splits (#9)",					/* 2% */
-	  C_BOOL, 2, 0, 0, &g.c_timing_stress_split_9, NULL },
-
 	{ "transaction_timestamps",				/* 10% */
 	  "enable transaction timestamp support",
 	  C_BOOL, 10, 0, 0, &g.c_txn_timestamps, NULL },
diff --git a/src/third_party/wiredtiger/test/format/format.h b/src/third_party/wiredtiger/test/format/format.h
index 1406d2b3fb5..83b75f70f26 100644
--- a/src/third_party/wiredtiger/test/format/format.h
+++ b/src/third_party/wiredtiger/test/format/format.h
@@ -222,7 +222,6 @@ typedef struct {
 	uint32_t c_timing_stress_split_6;
 	uint32_t c_timing_stress_split_7;
 	uint32_t c_timing_stress_split_8;
-	uint32_t c_timing_stress_split_9;
 	uint32_t c_truncate;
 	uint32_t c_txn_freq;
 	uint32_t c_txn_timestamps;
diff --git a/src/third_party/wiredtiger/test/format/wts.c b/src/third_party/wiredtiger/test/format/wts.c
index 8040142aa19..6452f74384d 100644
--- a/src/third_party/wiredtiger/test/format/wts.c
+++ b/src/third_party/wiredtiger/test/format/wts.c
@@ -264,8 +264,6 @@ wts_open(const char *home, bool set_api, WT_CONNECTION **connp)
 		CONFIG_APPEND(p, ",split_7");
 	if (g.c_timing_stress_split_8)
 		CONFIG_APPEND(p, ",split_8");
-	if (g.c_timing_stress_split_9)
-		CONFIG_APPEND(p, ",split_9");
 	CONFIG_APPEND(p, "]");
 
 	/* Extensions. */
diff --git a/src/third_party/wiredtiger/test/salvage/salvage.c b/src/third_party/wiredtiger/test/salvage/salvage.c
index 9c8a90d37b9..895a31620d9 100644
--- a/src/third_party/wiredtiger/test/salvage/salvage.c
+++ b/src/third_party/wiredtiger/test/salvage/salvage.c
@@ -670,7 +670,7 @@ empty(int cnt)
 
 	if (page_type == WT_PAGE_COL_FIX)
 		for (i = 0; i < cnt; ++i)
-			fputs("\\00\n", res_fp);
+			CHECK(fputs("\\00\n", res_fp));
 }
 
 /*
diff --git a/src/third_party/wiredtiger/test/suite/run.py b/src/third_party/wiredtiger/test/suite/run.py
index 6b668ad3e07..74fa259c3c4 100644
--- a/src/third_party/wiredtiger/test/suite/run.py
+++ b/src/third_party/wiredtiger/test/suite/run.py
@@ -238,7 +238,7 @@ if __name__ == '__main__':
     tests = unittest.TestSuite()
 
     # Turn numbers and ranges into test module names
-    preserve = timestamp = debug = dryRun = gdbSub = longtest = False
+    preserve = timestamp = debug = dryRun = gdbSub = lldbSub = longtest = False
     parallel = 0
     configfile = None
     configwrite = False
@@ -269,6 +269,9 @@ if __name__ == '__main__':
             if option == '-gdb' or option == 'g':
                 gdbSub = True
                 continue
+            if option == '-lldb':
+                lldbSub = True
+                continue
             if option == '-help' or option == 'h':
                 usage()
                 sys.exit(0)
@@ -323,7 +326,7 @@ if __name__ == '__main__':
 
     # All global variables should be set before any test classes are loaded.
     # That way, verbose printing can be done at the class definition level.
-    wttest.WiredTigerTestCase.globalSetup(preserve, timestamp, gdbSub,
+    wttest.WiredTigerTestCase.globalSetup(preserve, timestamp, gdbSub, lldbSub,
                                           verbose, wt_builddir, dirarg,
                                           longtest)
 
diff --git a/src/third_party/wiredtiger/test/suite/suite_subprocess.py b/src/third_party/wiredtiger/test/suite/suite_subprocess.py
index c2e9d99f691..4b0f6823e06 100644..100755
--- a/src/third_party/wiredtiger/test/suite/suite_subprocess.py
+++ b/src/third_party/wiredtiger/test/suite/suite_subprocess.py
@@ -26,7 +26,7 @@
 # ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 # OTHER DEALINGS IN THE SOFTWARE.
 
-import os, subprocess, sys
+import os, re, subprocess, sys
 from run import wt_builddir
 from wttest import WiredTigerTestCase
 
@@ -79,23 +79,51 @@ class suite_subprocess:
             print '********************************'
             self.fail('ERROR found in output file: ' + filename)
 
+    # If the string is of the form '/.../', then return just the embedded
+    # pattern, otherwise, return None
+    def convert_to_pattern(self, s):
+        if len(s) >= 2 and s[0] == '/' and s[-1] == '/':
+            return s[1:-1]
+        else:
+            return None
+
     def check_file_content(self, filename, expect):
         with open(filename, 'r') as f:
             got = f.read(len(expect) + 100)
             self.assertEqual(got, expect, filename + ': does not contain expected:\n\'' + expect + '\', but contains:\n\'' + got + '\'.')
 
-    def check_file_contains(self, filename, expect):
+    def check_file_contains_one_of(self, filename, expectlist):
         """
         Check that the file contains the expected string in the first 100K bytes
         """
         maxbytes = 1024*100
         with open(filename, 'r') as f:
             got = f.read(maxbytes)
-            if not (expect in got):
+            found = False
+            for expect in expectlist:
+                pat = self.convert_to_pattern(expect)
+                if pat == None:
+                    if expect in got:
+                        found = True
+                        break
+                else:
+                    if re.search(pat, got):
+                        found = True
+                        break
+            if not found:
+                if len(expectlist) == 1:
+                    expect = '\'' + expectlist[0] + '\''
+                else:
+                    expect = str(expectlist)
+                gotstr = '\'' + \
+                    (got if len(got) < 1000 else (got[0:1000] + '...')) + '\''
                 if len(got) >= maxbytes:
-                    self.fail(filename + ': does not contain expected \'' + expect + '\', or output is too large')
+                    self.fail(filename + ': does not contain expected ' + expect + ', or output is too large, got ' + gotstr)
                 else:
-                    self.fail(filename + ': does not contain expected \'' + expect + '\'')
+                    self.fail(filename + ': does not contain expected ' + expect + ', got ' + gotstr)
+
+    def check_file_contains(self, filename, expect):
+        self.check_file_contains_one_of(filename, [expect])
 
     def check_empty_file(self, filename):
         """
@@ -165,6 +193,8 @@ class suite_subprocess:
                 procargs = [ wtexe ]
                 if self._gdbSubprocess:
                     procargs = [ "gdb", "--args" ] + procargs
+                elif self._lldbSubprocess:
+                    procargs = [ "lldb", "--" ] + procargs
                 procargs.extend(args)
                 if self._gdbSubprocess:
                     infilepart = ""
@@ -177,6 +207,17 @@ class suite_subprocess:
                         ">" + wtoutname + " 2>" + wterrname
                     print "*********************************************"
                     returncode = subprocess.call(procargs)
+                elif self._lldbSubprocess:
+                    infilepart = ""
+                    if infilename != None:
+                        infilepart = "<" + infilename + " "
+                    print str(procargs)
+                    print "*********************************************"
+                    print "**** Run 'wt' via: run " + \
+                        " ".join(procargs[3:]) + infilepart + \
+                        ">" + wtoutname + " 2>" + wterrname
+                    print "*********************************************"
+                    returncode = subprocess.call(procargs)
                 elif infilename:
                     with open(infilename, "r") as wtin:
                         returncode = subprocess.call(
diff --git a/src/third_party/wiredtiger/test/suite/test_txn19.py b/src/third_party/wiredtiger/test/suite/test_txn19.py
new file mode 100755
index 00000000000..79b040a4cec
--- /dev/null
+++ b/src/third_party/wiredtiger/test/suite/test_txn19.py
@@ -0,0 +1,324 @@
+#!/usr/bin/env python
+#
+# Public Domain 2014-2018 MongoDB, Inc.
+# Public Domain 2008-2014 WiredTiger, Inc.
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+# test_txn19.py
+#   Transactions: test recovery with corrupted log files
+#
+
+import fnmatch, os, shutil, time
+from wtscenario import make_scenarios
+from suite_subprocess import suite_subprocess
+import wiredtiger, wttest
+
+# This test uses an artificially small log file limit, and creates
+# large records so two fit into a log file. This allows us to test
+# both the case when corruption happens at the beginning of a log file
+# (an even number of records have been created), and when corruption
+# happens in the middle of a log file (with an odd number of records).
+
+def corrupt(fname, truncate, offset, writeit):
+    with open(fname, 'r+') as log:
+        if truncate:
+            log.truncate()
+        if offset:
+            if offset < 0:  # Negative offset means seek to the end
+                log.seek(0, 2)
+            else:
+                log.seek(offset)
+        if writeit:
+            log.write(writeit)
+
+class test_txn19(wttest.WiredTigerTestCase, suite_subprocess):
+    base_config = 'log=(archive=false,enabled,file_max=100K),' + \
+                  'transaction_sync=(enabled,method=none)'
+    conn_config = base_config
+    corruption_type = [
+        ('removal', dict(kind='removal', f=lambda fname:
+            os.remove(fname))),
+        ('truncate', dict(kind='truncate', f=lambda fname:
+            corrupt(fname, True, 0, None))),
+        ('zero-begin', dict(kind='zero', f=lambda fname:
+            corrupt(fname, False, 0, '\0' * 4096))),
+        ('zero-trunc', dict(kind='zero', f=lambda fname:
+            corrupt(fname, True, 0, '\0' * 4096))),
+        ('zero-end', dict(kind='zero-end', f=lambda fname:
+            corrupt(fname, False, -1, '\0' * 4096))),
+        ('garbage-begin', dict(kind='garbage-begin', f=lambda fname:
+            corrupt(fname, False, 0, 'Bad!' * 1024))),
+        ('garbage-middle', dict(kind='garbage-middle', f=lambda fname:
+            corrupt(fname, False, 1024 * 25, 'Bad!' * 1024))),
+        ('garbage-end', dict(kind='garbage-end', f=lambda fname:
+            corrupt(fname, False, -1, 'Bad!' * 1024))),
+    ]
+    # The list comprehension below expands each entry in the integer tuple
+    # list to a scenario.  For example, (3, 4, 2) expands to:
+    # ('corrupt=[3,4],checkpoint=2', dict(corruptpos=3, corruptpos2=4, chkpt=2))
+    #
+    # Each number corresponds to a log file, so for this example, we have
+    # corruption in log file 3 (using the style of corruption from
+    # corruption_type), there is a second corruption in log file 4,
+    # and there is a checkpoint in log file 2.  A value of 0 means no
+    # corruption or checkpoint.
+    corruption_pos = [
+        ('corrupt=[' + str(x) + ',' + str(y) + '],checkpoint=' + str(z),
+           dict(corruptpos=x,corruptpos2=y,chkpt=z)) for (x,y,z) in (
+               (0, 0, 0), (0, 0, 2), (6, 0, 0), (6, 0, 3), (3, 0, 0),
+               (3, 0, 2), (3, 4, 2), (3, 5, 2), (3, 0, 4))]
+    nrecords = [('nrecords=10', dict(nrecords=10)),
+                ('nrecords=11', dict(nrecords=11))]
+
+    # This function prunes out unnecessary or problematic test cases
+    # from the list of scenarios.
+    def includeFunc(name, dictarg):
+        kind = dictarg['kind']
+        corruptpos = dictarg['corruptpos']
+        chkpt = dictarg['chkpt']
+
+        # corruptpos == 0 indicates there is no corruption.
+        # (i.e. corrupt log file 0, which doesn't exist)
+        # We do want to test the case of no corruption, but we don't
+        # need to try it against every type of corruption, only one.
+        if corruptpos == 0:
+            return kind == 'removal'
+
+        # NOTE:
+        # The removal or truncation of a middle log file (not first or last)
+        # that would be used in recovery is not currently handled gracefully.
+        if (kind == 'removal' or kind == 'truncate') and \
+           corruptpos != 6 and corruptpos > chkpt:
+            return False
+
+        # All the other cases are valid
+        return True
+
+    scenarios = make_scenarios(
+        corruption_type, corruption_pos, nrecords,
+        include=includeFunc, prune=20, prunelong=1000)
+
+    uri = 'table:test_txn19'
+    create_params = 'key_format=i,value_format=S'
+
+    # Return the log file number that contains the given record
+    # number.  In this test, two records fit into each log file, and
+    # after each even record is written, a new log file is created
+    # (having no records initially).  The last log file is this
+    # (nrecords/2 + 1), given that we start with log 1.
+    def record_to_logfile(self, recordnum):
+        return recordnum / 2 + 1
+
+    # Returns the first record number in a log file.
+    def logfile_to_record(self, logfile):
+        return (logfile - 1) * 2
+
+    # Return true if the log file is corrupted.
+    # If not corrupted, the log file will produce no errors,
+    # and all the records originally written should be recovered.
+    def corrupted(self):
+        # Corruptpos == 0 means to do no corruption in any log file
+        if self.corruptpos == 0:
+            return False
+
+        # Adding zeroes to the end of a log file is indistinguishable
+        # from having a log file that is preallocated that has not been
+        # totally filled. One might argue that if this does not occur
+        # in the final log file, it could/should have been truncated.
+        # At any rate, we consider this particular corruption to be benign.
+        if self.kind == 'zero-end':
+            return False
+
+        # NOTE:
+        # If garbage is added to an otherwise valid log file, the invalid
+        # portion is effectively 'skipped over'.
+        if self.kind == 'garbage-end':
+            return False
+        return True
+
+    def show_logs(self, homedir, msg):
+        loglist = []
+        for i in range(0, 10):
+            basename = 'WiredTigerLog.000000000' + str(i)
+            fullname = homedir + os.sep + basename
+            if os.path.isfile(fullname):
+                loglist.append(i)
+                if os.stat(fullname).st_size == 0:
+                    self.tty('LOGS ' + msg + ': ' + str(i) + ' is empty')
+        self.tty('LOGS ' + msg + ': ' + str(loglist))
+
+    def copy_for_crash_restart(self, olddir, newdir):
+        ''' Simulate a crash from olddir and restart in newdir. '''
+        # with the connection still open, copy files to new directory
+        shutil.rmtree(newdir, ignore_errors=True)
+        os.mkdir(newdir)
+        for fname in os.listdir(olddir):
+            fullname = os.path.join(olddir, fname)
+            # Skip lock file on Windows since it is locked
+            if os.path.isfile(fullname) and \
+                "WiredTiger.lock" not in fullname and \
+                "Tmplog" not in fullname and \
+                "Preplog" not in fullname:
+                shutil.copy(fullname, newdir)
+
+    # Generate a value that is a bit over half the size of the log file.
+    def valuegen(self, i):
+        return str(i) + 'A' * (1024 * 60)   # ~60K
+
+    # Insert a list of keys
+    def inserts(self, keylist):
+        c = self.session.open_cursor(self.uri)
+        for i in keylist:
+            if self.chkpt > 0 and self.logfile_to_record(self.chkpt) == i:
+                self.session.checkpoint()
+            c[i] = self.valuegen(i)
+        c.close()
+
+    def checks(self, expectlist):
+        c = self.session.open_cursor(self.uri, None, None)
+        gotlist = []
+        for key, value in c:
+            gotlist.append(key)
+            self.assertEqual(self.valuegen(key), value)
+        self.assertEqual(expectlist, gotlist)
+        c.close()
+
+    def log_number_to_file_name(self, homedir, n):
+        self.assertLess(n, 10)  # assuming 1 digit
+        return homedir + os.sep + 'WiredTigerLog.000000000' + str(n)
+
+    def corrupt_log(self, homedir):
+        if not self.corrupted():
+            return
+        self.f(self.log_number_to_file_name(homedir, self.corruptpos))
+
+        # Corrupt a second log file if needed
+        if self.corruptpos2 != 0:
+            self.f(self.log_number_to_file_name(homedir, self.corruptpos2))
+
+    # Return true iff the log has been damaged in a way that
+    # is not detected as a corruption.
+    # This includes:
+    #  - removal of the last log
+    #  - corruption in the middle of a log file.
+    def log_corrupt_but_valid(self):
+        # NOTE:
+        # Currently, corruption in the middle of a log file is not yet
+        # detected.
+        if self.kind == 'garbage-middle':
+            return True
+        if self.corruptpos == self.record_to_logfile(self.nrecords):
+            if self.kind == 'removal':
+                return True
+        return False
+
+    # For this test, at least, salvage identifies and fixes all
+    # recovery failures.
+    def expect_salvage_messages(self):
+        return self.expect_recovery_failure()
+
+    def expect_recovery_failure(self):
+        return self.corrupted() and \
+            self.corruptpos >= self.chkpt and \
+            not self.log_corrupt_but_valid()
+
+    def recovered_records(self):
+        if not self.corrupted() or self.chkpt > self.corruptpos:
+            return self.nrecords
+        return self.logfile_to_record(self.corruptpos)
+
+    def test_corrupt_log(self):
+        ''' Corrupt the log and restart with different kinds of recovery '''
+
+        # This test creates some data, then simulates a crash with corruption.
+        # Then does a restart with recovery, then starts again with salvage,
+        # and finally starts again with recovery (adding new records).
+
+        self.session.create(self.uri, self.create_params)
+        self.inserts([x for x in range(0, self.nrecords)])
+        newdir = "RESTART"
+        self.copy_for_crash_restart(self.home, newdir)
+        self.close_conn()
+        #self.show_logs(newdir, 'before corruption')
+        self.corrupt_log(newdir)
+        #self.show_logs(newdir, 'after corruption')
+        salvage_config = self.base_config + ',log=(recover=salvage)'
+        errfile = 'list.err'
+        outfile = 'list.out'
+        expect_fail = self.expect_recovery_failure()
+
+        # In cases of corruption, we cannot always call wiredtiger_open
+        # directly, because there may be a panic, and abort() is called
+        # in diagnostic mode which terminates the Python interpreter.
+        #
+        # Running any wt command externally to Python allows
+        # us to observe the failure or success safely.
+        # Use -R to force recover=on, which is the default for
+        # wiredtiger_open, (wt utilities normally have recover=error)
+        self.runWt(['-h', newdir, '-C', self.base_config, '-R', 'list'],
+            errfilename=errfile, outfilename=outfile, failure=expect_fail,
+            closeconn=False)
+
+        if expect_fail:
+            self.check_file_contains_one_of(errfile,
+            ['/log file.*corrupted/', 'WT_ERROR: non-specific WiredTiger error'])
+        else:
+            self.check_empty_file(errfile)
+            self.check_file_contains(outfile, self.uri)
+
+        found_records = self.recovered_records()
+        expect = [x for x in range(0, found_records)]
+
+        # If we are salvaging, expect an informational message
+        if self.expect_salvage_messages():
+            errpat = '.*'
+            # Possible messages:
+            #   salvage: log files x-y truncated at beginning
+            #   salvage: log file x truncated at beginning
+            #   salvage: log file x truncated
+            #   salvage: log file x removed
+            outpat = 'salvage: log file'
+        else:
+            errpat = '^$'
+            outpat = '^$'
+        with self.expectedStdoutPattern(outpat):
+            with self.expectedStderrPattern(errpat):
+                self.conn = self.wiredtiger_open(newdir, salvage_config)
+                self.session = self.setUpSessionOpen(self.conn)
+                self.checks(expect)
+
+        # Insert a couple more and simulate another crash.
+        newdir2 = "RESTART2"
+        self.inserts([self.nrecords, self.nrecords + 1])
+        expect.extend([self.nrecords, self.nrecords + 1])
+        self.copy_for_crash_restart(newdir, newdir2)
+        self.checks(expect)
+        self.reopen_conn(newdir)
+        self.checks(expect)
+        self.reopen_conn(newdir2, self.conn_config)
+        self.checks(expect)
+
+if __name__ == '__main__':
+    wttest.run()
diff --git a/src/third_party/wiredtiger/test/suite/wtscenario.py b/src/third_party/wiredtiger/test/suite/wtscenario.py
index 76824e428df..d953b7f627f 100644
--- a/src/third_party/wiredtiger/test/suite/wtscenario.py
+++ b/src/third_party/wiredtiger/test/suite/wtscenario.py
@@ -68,6 +68,9 @@ def make_scenarios(*args, **kwargs):
     """
     The standard way to create scenarios for WT tests.
     Scenarios can be combined by listing them all as arguments.
+    If some scenario combinations should not be included,
+    a include= argument function may be listed, which given a name and
+    dictionary argument, returns True if the scenario should be included.
     A final prune= and/or prunelong= argument may be given that
     forces the list of entries in the scenario to be pruned.
     The result is a (combined) scenario that has been checked
@@ -76,14 +79,19 @@ def make_scenarios(*args, **kwargs):
     scenes = multiply_scenarios('.', *args)
     pruneval = None
     prunelong = None
+    includefunc = None
     for key in kwargs:
         if key == 'prune':
             pruneval = kwargs[key]
         elif key == 'prunelong':
             prunelong = kwargs[key]
+        elif key == 'include':
+            includefunc = kwargs[key]
         else:
             raise AssertionError(
                 'make_scenarios: unexpected named arg: ' + key)
+    if includefunc:
+        scenes = [(name, d) for (name, d) in scenes if includefunc(name, d)]
     if pruneval != None or prunelong != None:
         pruneval = pruneval if pruneval != None else -1
         prunelong = prunelong if prunelong != None else -1
diff --git a/src/third_party/wiredtiger/test/suite/wttest.py b/src/third_party/wiredtiger/test/suite/wttest.py
index 8c0915bc9c7..1a2fddce031 100644
--- a/src/third_party/wiredtiger/test/suite/wttest.py
+++ b/src/third_party/wiredtiger/test/suite/wttest.py
@@ -101,7 +101,7 @@ class CapturedFd(object):
                                      ' unexpected ' + self.desc +
                                      ', contains:\n"' + contents + '"')
             testcase.fail('unexpected ' + self.desc + ', contains: "' +
-                      shortenWithEllipsis(contents,100) + '"')
+                      contents + '"')
         self.expectpos = filesize
 
     def checkAdditional(self, testcase, expect):
@@ -180,7 +180,7 @@ class WiredTigerTestCase(unittest.TestCase):
 
     @staticmethod
     def globalSetup(preserveFiles = False, useTimestamp = False,
-                    gdbSub = False, verbose = 1, builddir = None, dirarg = None,
+                    gdbSub = False, lldbSub = False, verbose = 1, builddir = None, dirarg = None,
                     longtest = False):
         WiredTigerTestCase._preserveFiles = preserveFiles
         d = 'WT_TEST' if dirarg == None else dirarg
@@ -194,6 +194,7 @@ class WiredTigerTestCase(unittest.TestCase):
         WiredTigerTestCase._origcwd = os.getcwd()
         WiredTigerTestCase._resultfile = open(os.path.join(d, 'results.txt'), "w", 0)  # unbuffered
         WiredTigerTestCase._gdbSubprocess = gdbSub
+        WiredTigerTestCase._lldbSubprocess = lldbSub
         WiredTigerTestCase._longtest = longtest
         WiredTigerTestCase._verbose = verbose
         WiredTigerTestCase._dupout = os.dup(sys.stdout.fileno())
@@ -339,20 +340,25 @@ class WiredTigerTestCase(unittest.TestCase):
             self.conn.close(config)
             self.conn = None
 
-    def open_conn(self, directory="."):
+    def open_conn(self, directory=".", config=None):
         """
         Open the connection if already closed.
         """
         if self.conn == None:
+            if config != None:
+                self._old_config = self.conn_config
+                self.conn_config = config
             self.conn = self.setUpConnectionOpen(directory)
+            if config != None:
+                self.conn_config = self._old_config
             self.session = self.setUpSessionOpen(self.conn)
 
-    def reopen_conn(self, directory="."):
+    def reopen_conn(self, directory=".", config=None):
         """
         Reopen the connection.
         """
         self.close_conn()
-        self.open_conn(directory)
+        self.open_conn(directory, config)
 
     def setUp(self):
         if not hasattr(self.__class__, 'wt_ntests'):