NULL MERGE this to 5.1

Apply the following InnoDB snapshots:
innodb-5.0-ss1319
innodb-5.0-ss1331
innodb-5.0-ss1333
innodb-5.0-ss1341

Fixes:
- Bug #21409: Incorrect result returned when in READ-COMMITTED with query_cache ON
  At low transaction isolation levels we let each consistent read set
  its own snapshot.
- Bug #23666: strange Innodb_row_lock_time_% values in show status; also millisecs wrong
  On Windows ut_usectime returns secs and usecs relative to the UNIX
  epoch (which is Jan, 1 1970).

- Bug #25494: LATEST DEADLOCK INFORMATION is not always cleared
  lock_deadlock_recursive(): When the search depth or length is exceeded,
  rewind lock_latest_err_file and display the two transactions at the
  point of aborting the search.

- Bug #25927: Foreign key with ON DELETE SET NULL on NOT NULL can crash server
  Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns for which
  there is a foreign key constraint ON ... SET NULL.

- Bug #26835: Repeatable corruption of utf8-enabled tables inside InnoDB
  The bug could be reproduced as follows:

  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.

  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.

  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.


innobase/dict/dict0dict.c:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1317:
  branches/5.0: Port r1316 from trunk:
  
  Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns for which
  there is a foreign key constraint ON ... SET NULL.  (Bug #25927)
  
  dict_foreign_find_index(): Add paramettter check_null.
  
  dict_foreign_add_to_cache(): Do not allow ON DELETE SET NULL
  or ON UPDATE SET NULL if any of the referencing columns are declared NOT NULL.
innobase/include/rem0rec.ic:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1339:
  branches/5.0: Merge r1338 from trunk:
  
  rec_offs_nth_size(): Treat n==0 as a special case.  (Bug #26835)
innobase/include/sync0sync.ic:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1293:
  branches/5.0: Fixed inline asm code, it didn't work with GCC > ver 3.x.
innobase/lock/lock0lock.c:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1331:
  branches/5.0: Merge r1330 from trunk:
  
  lock_deadlock_recursive(): When the search depth or length is exceeded,
  rewind lock_latest_err_file and display the two transactions at the
  point of aborting the search.  (Bug #25494)
  
  
  Revision r1333:
  branches/5.0: Merge r1332 from trunk:
  
  lock_deadlock_recursive(): When aborting the search, display a note
  regardless of start->undo_no.  Otherwise, aborted searches may show
  up as genuine deadlocks.  This mistake was made in r1330.
innobase/srv/srv0srv.c:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1261:
  branches/5.0: Fix for Bug# 23666. On Windows ut_usectime returns secs 
  and usecs relative to the UNIX epoch (which is Jan, 1 1970).
innobase/ut/ut0ut.c:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1261:
  branches/5.0: Fix for Bug# 23666. On Windows ut_usectime returns secs 
  and usecs relative to the UNIX epoch (which is Jan, 1 1970).
mysql-test/r/innodb.result:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1319:
  branches/5.0: Port r1318 from trunk:
  
  Add a test case for r1316 (Bug #25927).
  
  
  Revision r1328:
  branches/5.0: mysql-test: Merge changes from MySQL AB.
  
  
  Revision r1341:
  branches/5.0: Merge r1340 from trunk:
  
  innodb.test, innodb.result: Add test case for Bug #26835.
  The bug could be reproduced as follows:
  
  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.
  
  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.
  
  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.
  
  Revision r1284:
  Merge changes from MySQL AB:
  
  ChangeSet
    2007/01/24 14:49:36+04:00 holyfoot@mysql.com 
    bug #22682 Test fails --without-geometry
    geometry dependent parts moved to proper .test files
  
  mysql-test/r/innodb.result
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +0 -2
    result fixed
  
  mysql-test/r/innodb_gis.result
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +2 -0
    result fixed
  
  mysql-test/t/innodb.test
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +0 -6
    HAVE_GEOMETRY dependent part moved to innodb_gis.test
  
  mysql-test/t/innodb_gis.test
    2007/01/24 14:49:35+04:00 holyfoot@mysql.com +6 -0
    HAVE_GEOMETRY dependent part moved here from innodb.test
  
  
  Revision r1186:
  dict_load_foreign(): Use a local variable instead of the 10-bit field
  foreign->n_fields in order to preserve ON UPDATE CASCADE and
  ON DELETE CASCADE flags.  For some reason, gcc does not warn about
  shifting a 10-bit field to right by 24 bits.  (Bug #24741)
  
  This bug was introduced while reducing the memory footprint of the
  InnoDB data dictionary (Bug #20877).
  
  innodb.test, innodb.result: Add a test case.
  
  
  Revision r1318:
  Add a test case for r1316 (Bug #25927).
  
  
  Revision r1340:
  innodb.test, innodb.result: Add test case for Bug #26835.
  The bug could be reproduced as follows:
  
  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.
  
  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.
  
  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.
mysql-test/t/innodb.test:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1279:
  branches/5.0: Merge changes from MySQL AB:
  
  ChangeSet
    2006/11/20 22:42:06+02:00 monty@mysql.com 
    Remove compiler warnings
    (Mostly in DBUG_PRINT() and unused arguments)
    Fixed bug in query cache when used with traceing (--with-debug)
    Fixed memory leak in mysqldump
    Removed warnings from mysqltest scripts (replaced -- with #)
  
  mysql-test/t/innodb.test
    2006/11/20 22:41:41+02:00 monty@mysql.com +1 -1
    Remove mysqltest warnings
  
  sql/ha_innodb.cc
    2006/11/20 22:41:51+02:00 monty@mysql.com +2 -2
    Fixed compiler warning
  
  
  Revision r1319:
  branches/5.0: Port r1318 from trunk:
  
  Add a test case for r1316 (Bug #25927).
  
  
  Revision r1328:
  branches/5.0: mysql-test: Merge changes from MySQL AB.
  
  
  Revision r1341:
  branches/5.0: Merge r1340 from trunk:
  
  innodb.test, innodb.result: Add test case for Bug #26835.
  The bug could be reproduced as follows:
  
  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.
  
  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.
  
  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.
  
  Revision r1284:
  Merge changes from MySQL AB:
  
  ChangeSet
    2007/01/24 14:49:36+04:00 holyfoot@mysql.com 
    bug #22682 Test fails --without-geometry
    geometry dependent parts moved to proper .test files
  
  mysql-test/r/innodb.result
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +0 -2
    result fixed
  
  mysql-test/r/innodb_gis.result
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +2 -0
    result fixed
  
  mysql-test/t/innodb.test
    2007/01/24 14:49:34+04:00 holyfoot@mysql.com +0 -6
    HAVE_GEOMETRY dependent part moved to innodb_gis.test
  
  mysql-test/t/innodb_gis.test
    2007/01/24 14:49:35+04:00 holyfoot@mysql.com +6 -0
    HAVE_GEOMETRY dependent part moved here from innodb.test
  
  
  Revision r1283:
  Merge changes from MySQL AB:
  
  ChangeSet
    2007/01/22 18:42:52+02:00 monty@mysql.com 
    Give warnings for unused objects
    Changed error message to be compatible with old error file
    Added new error message for new DUP_ENTRY syntax
  
  mysql-test/t/innodb.test
    2007/01/22 18:42:49+02:00 monty@mysql.com +14 -14
    Changed to use new error message
  
  
  Revision r1186:
  dict_load_foreign(): Use a local variable instead of the 10-bit field
  foreign->n_fields in order to preserve ON UPDATE CASCADE and
  ON DELETE CASCADE flags.  For some reason, gcc does not warn about
  shifting a 10-bit field to right by 24 bits.  (Bug #24741)
  
  This bug was introduced while reducing the memory footprint of the
  InnoDB data dictionary (Bug #20877).
  
  innodb.test, innodb.result: Add a test case.
  
  
  Revision r1318:
  Add a test case for r1316 (Bug #25927).
  
  
  Revision r1329:
  Merge changes from MySQL AB to mysql-test directives.
  The results are not affected.
  
  
  Revision r1340:
  innodb.test, innodb.result: Add test case for Bug #26835.
  The bug could be reproduced as follows:
  
  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.
  
  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.
  
  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.
sql/ha_innodb.cc:
  NULL MERGE this to 5.1
  
  Apply the following InnoDB snapshots:
  innodb-5.0-ss1319
  innodb-5.0-ss1331
  innodb-5.0-ss1333
  innodb-5.0-ss1341
  
  Revision r1279:
  branches/5.0: Merge changes from MySQL AB:
  
  ChangeSet
    2006/11/20 22:42:06+02:00 monty@mysql.com 
    Remove compiler warnings
    (Mostly in DBUG_PRINT() and unused arguments)
    Fixed bug in query cache when used with traceing (--with-debug)
    Fixed memory leak in mysqldump
    Removed warnings from mysqltest scripts (replaced -- with #)
  
  mysql-test/t/innodb.test
    2006/11/20 22:41:41+02:00 monty@mysql.com +1 -1
    Remove mysqltest warnings
  
  sql/ha_innodb.cc
    2006/11/20 22:41:51+02:00 monty@mysql.com +2 -2
    Fixed compiler warning
  
  
  Revision r1280:
  branches/5.0: Merge a change from MySQL AB:
  
  ChangeSet
    2006/11/30 18:25:05+02:00 monty@mysql.com 
    Fixed portability issue in my_thr_init.c (was added in my last push)
    
    Fixed compiler warnings (detected by VC++):
    - Removed not used variables
    - Added casts
    - Fixed wrong assignments to bool
    - Fixed wrong calls with bool arguments
    - Added missing argument to store(longlong), which caused wrong store
    method to be called.
  
  sql/ha_innodb.cc
    2006/11/30 18:24:53+02:00 monty@mysql.com +0 -1
    Removed not used variable
  
  
  Revision r1260:
  branches/5.0: Fix for Bug# 21409. At low transaction isolation levels
  we let each consistent read set its own snapshot.
  
  
  Revision r1326:
  branches/5.0: Merge code from MySQL AB:
  
  ChangeSet@1.2417.3.1  2007-02-22 16:59:57+02:00  monty@mysql.fi
  
  Fixed compiler warnings (for linux and win32 and win64)

9 files changed, 172 insertions, 54 deletions

diff --git a/innobase/dict/dict0dict.c b/innobase/dict/dict0dict.c
index df48a8a4b5a..33aebb25071 100644
--- a/innobase/dict/dict0dict.c
+++ b/innobase/dict/dict0dict.c
@@ -2139,9 +2139,12 @@ dict_foreign_find_index(
 	ulint		n_cols,	/* in: number of columns */
 	dict_index_t*	types_idx, /* in: NULL or an index to whose types the
 				   column types must match */
-	ibool		check_charsets)	/* in: whether to check charsets.
+	ibool		check_charsets,	/* in: whether to check charsets.
 					only has an effect if types_idx !=
 					NULL. */
+	ulint		check_null)
+				/* in: nonzero if none of the columns must
+				be declared NOT NULL */
 {
 #ifndef UNIV_HOTBACKUP
 	dict_index_t*	index;
@@ -2154,10 +2157,11 @@ dict_foreign_find_index(
 		if (dict_index_get_n_fields(index) >= n_cols) {
 
 			for (i = 0; i < n_cols; i++) {
-				col_name = dict_index_get_nth_field(index, i)
-							->col->name;
-				if (dict_index_get_nth_field(index, i)
-						->prefix_len != 0) {
+				dict_field_t*	field
+					= dict_index_get_nth_field(index, i);
+
+				col_name = field->col->name;
+				if (field->prefix_len != 0) {
 					/* We do not accept column prefix
 					indexes here */
 					
@@ -2169,6 +2173,13 @@ dict_foreign_find_index(
 				  	break;
 				}
 
+				if (check_null
+				    && (field->col->type.prtype
+					& DATA_NOT_NULL)) {
+
+					return(NULL);
+				}
+
 				if (types_idx && !cmp_types_are_equal(
 				     dict_index_get_nth_type(index, i),
 				     dict_index_get_nth_type(types_idx, i),
@@ -2290,7 +2301,7 @@ dict_foreign_add_to_cache(
 		index = dict_foreign_find_index(ref_table,
 			(const char**) for_in_cache->referenced_col_names,
 			for_in_cache->n_fields,
-			for_in_cache->foreign_index, check_charsets);
+			for_in_cache->foreign_index, check_charsets, FALSE);
 
 		if (index == NULL) {
 			dict_foreign_error_report(ef, for_in_cache,
@@ -2317,13 +2328,17 @@ dict_foreign_add_to_cache(
 		index = dict_foreign_find_index(for_table,
 			(const char**) for_in_cache->foreign_col_names,
 			for_in_cache->n_fields,
-			for_in_cache->referenced_index, check_charsets);
+			for_in_cache->referenced_index, check_charsets,
+			for_in_cache->type
+			& (DICT_FOREIGN_ON_DELETE_SET_NULL
+			   | DICT_FOREIGN_ON_UPDATE_SET_NULL));
 
 		if (index == NULL) {
 			dict_foreign_error_report(ef, for_in_cache,
 "there is no index in the table which would contain\n"
 "the columns as the first columns, or the data types in the\n"
-"table do not match to the ones in the referenced table.");
+"table do not match to the ones in the referenced table\n"
+"or one of the ON ... SET NULL columns is declared NOT NULL.");
 
 			if (for_in_cache == foreign) {
 				if (added_to_referenced_list) {
@@ -3125,7 +3140,8 @@ col_loop1:
 	/* Try to find an index which contains the columns
 	as the first fields and in the right order */
 
-	index = dict_foreign_find_index(table, column_names, i, NULL, TRUE);
+	index = dict_foreign_find_index(table, column_names, i,
+					NULL, TRUE, FALSE);
 
 	if (!index) {
 		mutex_enter(&dict_foreign_err_mutex);
@@ -3390,7 +3406,7 @@ try_find_index:
 
 	if (referenced_table) {
 		index = dict_foreign_find_index(referenced_table,
-			column_names, i, foreign->foreign_index, TRUE);
+			column_names, i, foreign->foreign_index, TRUE, FALSE);
 		if (!index) {
 			dict_foreign_free(foreign);
 			mutex_enter(&dict_foreign_err_mutex);
diff --git a/innobase/include/rem0rec.ic b/innobase/include/rem0rec.ic
index 9c24f385f4f..1abbb503bab 100644
--- a/innobase/include/rem0rec.ic
+++ b/innobase/include/rem0rec.ic
@@ -982,6 +982,9 @@ rec_offs_nth_size(
 {
 	ut_ad(rec_offs_validate(NULL, NULL, offsets));
 	ut_ad(n < rec_offs_n_fields(offsets));
+	if (!n) {
+		return(rec_offs_base(offsets)[1 + n] & REC_OFFS_MASK);
+	}
 	return((rec_offs_base(offsets)[1 + n] - rec_offs_base(offsets)[n])
 			& REC_OFFS_MASK);
 }
diff --git a/innobase/include/sync0sync.ic b/innobase/include/sync0sync.ic
index a32a82d6e8b..e5c6f56d8ba 100644
--- a/innobase/include/sync0sync.ic
+++ b/innobase/include/sync0sync.ic
@@ -6,6 +6,16 @@ Mutex, the basic synchronization primitive
 Created 9/5/1995 Heikki Tuuri
 *******************************************************/
 
+#if defined(not_defined) && defined(__GNUC__) && defined(UNIV_INTEL_X86)
+/* %z0: Use the size of operand %0 which in our case is *m to determine
+instruction size, it should end up as xchgl. "1" in the input constraint,
+says that "in" has to go in the same place as "out".*/
+#define TAS(m, in, out) \
+	asm volatile ("xchg%z0 %2, %0" \
+	: "=g" (*(m)), "=r" (out) \
+	: "1" (in))	/* Note: "1" here refers to "=r" (out) */
+#endif
+
 /**********************************************************************
 Sets the waiters field in a mutex. */
 
@@ -85,20 +95,10 @@ mutex_test_and_set(
 
 	return(res);
 #elif defined(not_defined) && defined(__GNUC__) && defined(UNIV_INTEL_X86)
-	ulint*	lw;
 	ulint	res;
 
-	lw = &(mutex->lock_word);
-
-	/* In assembly we use the so-called AT & T syntax where
-	the order of operands is inverted compared to the ordinary Intel
-	syntax. The 'l' after the mnemonics denotes a 32-bit operation.
-	The line after the code tells which values come out of the asm
-	code, and the second line tells the input to the asm code. */
+	TAS(&mutex->lock_word, 1, res);
 
-	asm volatile("movl $1, %%eax; xchgl (%%ecx), %%eax" :
-	              "=eax" (res), "=m" (*lw) :
-	              "ecx" (lw));
 	return(res);
 #else
 	ibool	ret;
@@ -137,20 +137,9 @@ mutex_reset_lock_word(
         __asm   MOV     ECX, lw
         __asm   XCHG    EDX, DWORD PTR [ECX]                    
 #elif defined(not_defined) && defined(__GNUC__) && defined(UNIV_INTEL_X86)
-	ulint*	lw;
-
-	lw = &(mutex->lock_word);
-
-	/* In assembly we use the so-called AT & T syntax where
-	the order of operands is inverted compared to the ordinary Intel
-	syntax. The 'l' after the mnemonics denotes a 32-bit operation. */
+	ulint	res;
 
-	asm volatile("movl $0, %%eax; xchgl (%%ecx), %%eax" :
-	              "=m" (*lw) :
-	              "ecx" (lw) :
-		      "eax");	/* gcc does not seem to understand
-				that our asm code resets eax: tell it
-				explicitly that after the third ':' */
+	TAS(&mutex->lock_word, 0, res);
 #else
 	mutex->lock_word = 0;
 
diff --git a/innobase/lock/lock0lock.c b/innobase/lock/lock0lock.c
index 06475c8ef7e..77dfca5fdf4 100644
--- a/innobase/lock/lock0lock.c
+++ b/innobase/lock/lock0lock.c
@@ -3259,12 +3259,6 @@ lock_deadlock_recursive(
 
 	*cost = *cost + 1;
 
-	if ((depth > LOCK_MAX_DEPTH_IN_DEADLOCK_CHECK)
-		|| (*cost > LOCK_MAX_N_STEPS_IN_DEADLOCK_CHECK)) {
-
-		return(LOCK_VICTIM_IS_START);
-	}
-
 	lock = wait_lock;
 
 	if (lock_get_type(wait_lock) == LOCK_REC) {
@@ -3296,11 +3290,18 @@ lock_deadlock_recursive(
 
 		if (lock_has_to_wait(wait_lock, lock)) {
 
+			ibool	too_far
+				= depth > LOCK_MAX_DEPTH_IN_DEADLOCK_CHECK
+				|| *cost > LOCK_MAX_N_STEPS_IN_DEADLOCK_CHECK;
+
 			lock_trx = lock->trx;
 
-			if (lock_trx == start) {
+			if (lock_trx == start || too_far) {
+
 				/* We came back to the recursion starting
-				point: a deadlock detected */
+				point: a deadlock detected; or we have
+				searched the waits-for graph too long */
+
 				FILE*	ef = lock_latest_err_file;
 				
 				rewind(ef);
@@ -3342,9 +3343,20 @@ lock_deadlock_recursive(
 				}
 #ifdef UNIV_DEBUG
 				if (lock_print_waits) {
-					fputs("Deadlock detected\n", stderr);
+					fputs("Deadlock detected"
+					      " or too long search\n",
+					      stderr);
 				}
 #endif /* UNIV_DEBUG */
+				if (too_far) {
+
+					fputs("TOO DEEP OR LONG SEARCH"
+					      " IN THE LOCK TABLE"
+					      " WAITS-FOR GRAPH\n", ef);
+
+					return(LOCK_VICTIM_IS_START);
+				}
+
 				if (ut_dulint_cmp(wait_lock->trx->undo_no,
 							start->undo_no) >= 0) {
 					/* Our recursion starting point
diff --git a/innobase/srv/srv0srv.c b/innobase/srv/srv0srv.c
index fe9e08d65be..96c0f05111b 100644
--- a/innobase/srv/srv0srv.c
+++ b/innobase/srv/srv0srv.c
@@ -1822,14 +1822,14 @@ srv_export_innodb_status(void)
         export_vars.innodb_pages_written= buf_pool->n_pages_written;
         export_vars.innodb_row_lock_waits= srv_n_lock_wait_count;
         export_vars.innodb_row_lock_current_waits= srv_n_lock_wait_current_count;
-        export_vars.innodb_row_lock_time= srv_n_lock_wait_time / 10000;
+        export_vars.innodb_row_lock_time= srv_n_lock_wait_time / 1000;
 	if (srv_n_lock_wait_count > 0) {
 		export_vars.innodb_row_lock_time_avg = (ulint)
-			(srv_n_lock_wait_time / 10000 / srv_n_lock_wait_count);
+			(srv_n_lock_wait_time / 1000 / srv_n_lock_wait_count);
 	} else {
 		export_vars.innodb_row_lock_time_avg = 0;
 	}
-        export_vars.innodb_row_lock_time_max= srv_n_lock_max_wait_time / 10000;
+        export_vars.innodb_row_lock_time_max= srv_n_lock_max_wait_time / 1000;
         export_vars.innodb_rows_read= srv_n_rows_read;
         export_vars.innodb_rows_inserted= srv_n_rows_inserted;
         export_vars.innodb_rows_updated= srv_n_rows_updated;
diff --git a/innobase/ut/ut0ut.c b/innobase/ut/ut0ut.c
index 1be5939303a..feb03269d91 100644
--- a/innobase/ut/ut0ut.c
+++ b/innobase/ut/ut0ut.c
@@ -20,6 +20,55 @@ Created 5/11/1994 Heikki Tuuri
 
 ibool	ut_always_false	= FALSE;
 
+#ifdef __WIN__
+/*********************************************************************
+NOTE: The Windows epoch starts from 1601/01/01 whereas the Unix
+epoch starts from 1970/1/1. For selection of constant see:
+http://support.microsoft.com/kb/167296/ */
+#define WIN_TO_UNIX_DELTA_USEC  ((ib_longlong) 11644473600000000ULL)
+
+
+/*********************************************************************
+This is the Windows version of gettimeofday(2).*/
+static
+int
+ut_gettimeofday(
+/*============*/
+				/* out: 0 if all OK else -1 */
+	struct timeval*	tv,	/* out: Values are relative to Unix epoch */
+	void*		tz)	/* in: not used */
+{
+	FILETIME	ft;
+	ib_longlong	tm;
+
+	if (!tv) {
+		errno = EINVAL;
+		return(-1);
+	}
+
+	GetSystemTimeAsFileTime(&ft);
+
+	tm = (ib_longlong) ft.dwHighDateTime << 32;
+	tm |= ft.dwLowDateTime;
+
+	ut_a(tm >= 0);	/* If tm wraps over to negative, the quotient / 10
+			does not work */
+
+	tm /= 10;	/* Convert from 100 nsec periods to usec */
+
+	/* If we don't convert to the Unix epoch the value for
+	struct timeval::tv_sec will overflow.*/
+	tm -= WIN_TO_UNIX_DELTA_USEC;
+
+	tv->tv_sec  = (long) (tm / 1000000L);
+	tv->tv_usec = (long) (tm % 1000000L);
+
+	return(0);
+}
+#else
+#define	ut_gettimeofday		gettimeofday
+#endif
+
 /*********************************************************************
 Get the quote character to be used in SQL identifiers.
 This definition must match the one in sql/ha_innodb.cc! */
@@ -82,17 +131,11 @@ ut_usectime(
 	ulint*	sec,	/* out: seconds since the Epoch */
 	ulint*	ms)	/* out: microseconds since the Epoch+*sec */
 {
-#ifdef __WIN__
-	SYSTEMTIME st;
-	GetLocalTime(&st);
-	*sec = (ulint) st.wSecond;
-	*ms  = (ulint) st.wMilliseconds;
-#else
 	struct timeval	tv;
-	gettimeofday(&tv,NULL);
+
+	ut_gettimeofday(&tv, NULL);
 	*sec = (ulint) tv.tv_sec;
 	*ms  = (ulint) tv.tv_usec;
-#endif
 }
 
 /**************************************************************
diff --git a/mysql-test/r/innodb.result b/mysql-test/r/innodb.result
index 99f0d4100ee..0638152ba42 100644
--- a/mysql-test/r/innodb.result
+++ b/mysql-test/r/innodb.result
@@ -2968,3 +2968,21 @@ a
 drop table t2, t1;
 create table t1 (g geometry not null, spatial gk(g)) engine=innodb;
 ERROR HY000: The used table type doesn't support SPATIAL indexes
+CREATE TABLE t1 (a INT, INDEX(a)) ENGINE=InnoDB;
+CREATE TABLE t2 (a INT, INDEX(a)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (1);
+ALTER TABLE t2 ADD FOREIGN KEY (a) REFERENCES t1 (a) ON DELETE SET NULL;
+ALTER TABLE t2 MODIFY a INT NOT NULL;
+ERROR HY000: Error on rename of '#sql-temporary' to './test/t2' (errno: 150)
+DELETE FROM t1;
+DROP TABLE t2,t1;
+CREATE TABLE t1 (a VARCHAR(5) COLLATE utf8_unicode_ci PRIMARY KEY)
+ENGINE=InnoDB;
+INSERT INTO t1 VALUES (0xEFBCA4EFBCA4EFBCA4);
+DELETE FROM t1;
+INSERT INTO t1 VALUES ('DDD');
+SELECT * FROM t1;
+a
+DDD
+DROP TABLE t1;
diff --git a/mysql-test/t/innodb.test b/mysql-test/t/innodb.test
index aa25677bd99..e762d740d66 100644
--- a/mysql-test/t/innodb.test
+++ b/mysql-test/t/innodb.test
@@ -1976,6 +1976,34 @@ drop table t2, t1;
 --error ER_TABLE_CANT_HANDLE_SPKEYS
 create table t1 (g geometry not null, spatial gk(g)) engine=innodb;
 
+#
+# Bug #25927: Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns
+# for which there is a foreign key constraint ON ... SET NULL.
+#
+
+CREATE TABLE t1 (a INT, INDEX(a)) ENGINE=InnoDB;
+CREATE TABLE t2 (a INT, INDEX(a)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (1);
+ALTER TABLE t2 ADD FOREIGN KEY (a) REFERENCES t1 (a) ON DELETE SET NULL;
+--replace_regex /'\.\/test\/#sql-[0-9a-f_]*'/'#sql-temporary'/
+--error 1025
+ALTER TABLE t2 MODIFY a INT NOT NULL;
+DELETE FROM t1;
+DROP TABLE t2,t1;
+
+#
+# Bug #26835: table corruption after delete+insert
+#
+
+CREATE TABLE t1 (a VARCHAR(5) COLLATE utf8_unicode_ci PRIMARY KEY)
+ENGINE=InnoDB;
+INSERT INTO t1 VALUES (0xEFBCA4EFBCA4EFBCA4);
+DELETE FROM t1;
+INSERT INTO t1 VALUES ('DDD');
+SELECT * FROM t1;
+DROP TABLE t1;
+
 #######################################################################
 #                                                                     #
 # Please, DO NOT TOUCH this file as well as the innodb.result file.   #
diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc
index cbefa9d3949..217f59d4b7e 100644
--- a/sql/ha_innodb.cc
+++ b/sql/ha_innodb.cc
@@ -6066,6 +6066,15 @@ ha_innobase::external_lock(
 		        trx->isolation_level = innobase_map_isolation_level(
 						(enum_tx_isolation)
 						thd->variables.tx_isolation);
+
+	                      if (trx->isolation_level <= TRX_ISO_READ_COMMITTED
+				  && trx->global_read_view) {
+
+				/* At low transaction isolation levels we let
+				each consistent read set its own snapshot */
+
+				read_view_close_for_mysql(trx);
+                        }
 		}
 
 		if (trx->isolation_level == TRX_ISO_SERIALIZABLE