WT-2494: review calls to __wt_free, plus minor bug in an error path.

Remove checks for "pointer != NULL" before calling __wt_free(), they're
not needed.

In __wt_async_op_init(), don't bother clearing the pointer values after
calling __wt_free(), they get cleared by __wt_free().

In __lsm_tree_set_name(), don't leave the tree without a name, by freeing
the name and then failing to allocate room for the new one.

In __ckpt_last_name(), don't free the wrong pointer in the error path.

13 files changed, 27 insertions, 45 deletions

diff --git a/src/async/async_op.c b/src/async/async_op.c
index 130c704757b..970c33c3360 100644
--- a/src/async/async_op.c
+++ b/src/async/async_op.c
@@ -349,14 +349,8 @@ __wt_async_op_init(WT_SESSION_IMPL *session)
 		WT_ERR(__async_op_init(conn, op, i));
 	}
 	return (0);
-err:
-	if (async->async_ops != NULL) {
-		__wt_free(session, async->async_ops);
-		async->async_ops = NULL;
-	}
-	if (async->async_queue != NULL) {
-		__wt_free(session, async->async_queue);
-		async->async_queue = NULL;
-	}
+
+err:	__wt_free(session, async->async_ops);
+	__wt_free(session, async->async_queue);
 	return (ret);
 }
diff --git a/src/btree/bt_discard.c b/src/btree/bt_discard.c
index 795111d53f9..1f739c9572e 100644
--- a/src/btree/bt_discard.c
+++ b/src/btree/bt_discard.c
@@ -337,8 +337,7 @@ __free_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page)
 		copy = WT_ROW_KEY_COPY(rip);
 		(void)__wt_row_leaf_key_info(
 		    page, copy, &ikey, NULL, NULL, NULL);
-		if (ikey != NULL)
-			__wt_free(session, ikey);
+		__wt_free(session, ikey);
 	}
 
 	/*
diff --git a/src/btree/bt_read.c b/src/btree/bt_read.c
index f80eb09153c..5cf6a9bf2bc 100644
--- a/src/btree/bt_read.c
+++ b/src/btree/bt_read.c
@@ -281,10 +281,8 @@ err:	WT_TRET(__wt_las_cursor_close(session, &cursor, session_flags));
 	 * On error, upd points to a single unlinked WT_UPDATE structure,
 	 * first_upd points to a list.
 	 */
-	if (upd != NULL)
-		__wt_free(session, upd);
-	if (first_upd != NULL)
-		__wt_free_update_list(session, first_upd);
+	__wt_free(session, upd);
+	__wt_free_update_list(session, first_upd);
 
 	__wt_scr_free(session, &current_key);
 	__wt_scr_free(session, &las_addr);
diff --git a/src/btree/bt_slvg.c b/src/btree/bt_slvg.c
index 8d78bda79fb..0e064d306b6 100644
--- a/src/btree/bt_slvg.c
+++ b/src/btree/bt_slvg.c
@@ -1206,8 +1206,7 @@ __slvg_col_build_internal(
 	__wt_root_ref_init(&ss->root_ref, page, true);
 
 	if (0) {
-err:		if (addr != NULL)
-			__wt_free(session, addr);
+err:		__wt_free(session, addr);
 		__wt_page_out(session, &page);
 	}
 	return (ret);
@@ -1868,8 +1867,7 @@ __slvg_row_build_internal(
 	__wt_root_ref_init(&ss->root_ref, page, false);
 
 	if (0) {
-err:		if (addr != NULL)
-			__wt_free(session, addr);
+err:		__wt_free(session, addr);
 		__wt_page_out(session, &page);
 	}
 	return (ret);
diff --git a/src/btree/bt_split.c b/src/btree/bt_split.c
index 3dea03316ce..4f16a290958 100644
--- a/src/btree/bt_split.c
+++ b/src/btree/bt_split.c
@@ -151,8 +151,7 @@ __wt_split_stash_discard_all(
 	for (i = 0, stash = session->split_stash;
 	    i < session->split_stash_cnt;
 	    ++i, ++stash)
-		if (stash->p != NULL)
-			__wt_free(session_safe, stash->p);
+		__wt_free(session_safe, stash->p);
 
 	__wt_free(session_safe, session->split_stash);
 	session->split_stash_cnt = session->split_stash_alloc = 0;
diff --git a/src/conn/conn_open.c b/src/conn/conn_open.c
index 58577b4587d..aff422654d7 100644
--- a/src/conn/conn_open.c
+++ b/src/conn/conn_open.c
@@ -210,10 +210,8 @@ __wt_connection_close(WT_CONNECTION_IMPL *conn)
 			/*
 			 * If hash arrays were allocated, free them now.
 			 */
-			if (s->dhhash != NULL)
-				__wt_free(session, s->dhhash);
-			if (s->tablehash != NULL)
-				__wt_free(session, s->tablehash);
+			__wt_free(session, s->dhhash);
+			__wt_free(session, s->tablehash);
 			__wt_free(session, s->hazard);
 		}
 
diff --git a/src/cursor/cur_join.c b/src/cursor/cur_join.c
index 8f69f748f9d..33e4f2580b6 100644
--- a/src/cursor/cur_join.c
+++ b/src/cursor/cur_join.c
@@ -1127,8 +1127,7 @@ __wt_curjoin_join(WT_SESSION_IMPL *session, WT_CURSOR_JOIN *cjoin,
 		    cindex->iface.key_format);
 	}
 
-err:	if (main_uri != NULL)
-		__wt_free(session, main_uri);
+err:	__wt_free(session, main_uri);
 	return (ret);
 }
 
diff --git a/src/log/log.c b/src/log/log.c
index 0b47308cfd8..e41073299a8 100644
--- a/src/log/log.c
+++ b/src/log/log.c
@@ -1252,10 +1252,8 @@ __log_has_hole(WT_SESSION_IMPL *session, WT_FH *fh, wt_off_t offset, bool *hole)
 		}
 	}
 
-err:	if (buf != NULL)
-		__wt_free(session, buf);
-	if (zerobuf != NULL)
-		__wt_free(session, zerobuf);
+err:	__wt_free(session, buf);
+	__wt_free(session, zerobuf);
 	return (ret);
 }
 
diff --git a/src/lsm/lsm_tree.c b/src/lsm/lsm_tree.c
index 45994bae42b..70ac912f333 100644
--- a/src/lsm/lsm_tree.c
+++ b/src/lsm/lsm_tree.c
@@ -157,9 +157,12 @@ static int
 __lsm_tree_set_name(WT_SESSION_IMPL *session,
     WT_LSM_TREE *lsm_tree, const char *uri)
 {
-	if (lsm_tree->name != NULL)
-		__wt_free(session, lsm_tree->name);
-	WT_RET(__wt_strdup(session, uri, &lsm_tree->name));
+	void *p;
+
+	WT_RET(__wt_strdup(session, uri, &p));
+
+	__wt_free(session, lsm_tree->name);
+	lsm_tree->name = p;
 	lsm_tree->filename = lsm_tree->name + strlen("lsm:");
 	return (0);
 }
@@ -950,8 +953,8 @@ __wt_lsm_tree_rename(WT_SESSION_IMPL *session,
 
 err:	if (locked)
 		WT_TRET(__wt_lsm_tree_writeunlock(session, lsm_tree));
-	if (old != NULL)
-		__wt_free(session, old);
+	__wt_free(session, old);
+
 	/*
 	 * Discard this LSM tree structure. The first operation on the renamed
 	 * tree will create a new one.
diff --git a/src/meta/meta_ckpt.c b/src/meta/meta_ckpt.c
index df4cd2cb4d6..0a864432daf 100644
--- a/src/meta/meta_ckpt.c
+++ b/src/meta/meta_ckpt.c
@@ -212,8 +212,7 @@ __ckpt_last_name(
 		if (found && a.val < found)
 			continue;
 
-		if (*namep != NULL)
-			__wt_free(session, *namep);
+		__wt_free(session, *namep);
 		WT_ERR(__wt_strndup(session, k.str, k.len, namep));
 		found = a.val;
 	}
@@ -221,7 +220,7 @@ __ckpt_last_name(
 		ret = WT_NOTFOUND;
 
 	if (0) {
-err:		__wt_free(session, namep);
+err:		__wt_free(session, *namep);
 	}
 	return (ret);
 }
diff --git a/src/os_posix/os_stdio.c b/src/os_posix/os_stdio.c
index 7ab107eda1e..65a0f40a659 100644
--- a/src/os_posix/os_stdio.c
+++ b/src/os_posix/os_stdio.c
@@ -46,8 +46,7 @@ __wt_fopen(WT_SESSION_IMPL *session,
 	if (*fpp == NULL)
 		ret = __wt_errno();
 
-	if (pathbuf != NULL)
-		__wt_free(session, pathbuf);
+	__wt_free(session, pathbuf);
 
 	if (ret == 0)
 		return (0);
diff --git a/src/packing/pack_stream.c b/src/packing/pack_stream.c
index 5716c31a9c2..1393eb9a9c1 100644
--- a/src/packing/pack_stream.c
+++ b/src/packing/pack_stream.c
@@ -65,8 +65,7 @@ wiredtiger_pack_close(WT_PACK_STREAM *ps, size_t *usedp)
 	if (usedp != NULL)
 		*usedp = WT_PTRDIFF(ps->p, ps->start);
 
-	if (ps != NULL)
-		__wt_free(ps->pack.session, ps);
+	__wt_free(ps->pack.session, ps);
 
 	return (0);
 }
diff --git a/src/schema/schema_open.c b/src/schema/schema_open.c
index 49318f80959..e7ce4e42498 100644
--- a/src/schema/schema_open.c
+++ b/src/schema/schema_open.c
@@ -109,8 +109,7 @@ __wt_schema_open_colgroups(WT_SESSION_IMPL *session, WT_TABLE *table)
 
 err:	__wt_scr_free(session, &buf);
 	__wt_schema_destroy_colgroup(session, &colgroup);
-	if (cgconfig != NULL)
-		__wt_free(session, cgconfig);
+	__wt_free(session, cgconfig);
 	return (ret);
 }