diff --git a/mysql-test/suite/innodb/include/innodb_bulk_create_index_debug.inc b/mysql-test/suite/innodb/include/innodb_bulk_create_index_debug.inc
index 48de3a1962d..85466e5e4ae 100644
--- a/mysql-test/suite/innodb/include/innodb_bulk_create_index_debug.inc
+++ b/mysql-test/suite/innodb/include/innodb_bulk_create_index_debug.inc
@@ -4,17 +4,8 @@
 
 # Not supported in embedded
 -- source include/not_embedded.inc
-
-# This test case needs to crash the server. Needs a debug server.
 -- source include/have_debug.inc
-
-# Don't test this under valgrind, memory leaks will occur.
--- source include/not_valgrind.inc
-
-# Avoid CrashReporter popup on Mac
--- source include/not_crashrep.inc
-
--- source include/have_innodb.inc
+-- source include/have_debug_sync.inc
 
 # Create Insert Procedure
 DELIMITER |;
@@ -62,21 +53,11 @@ CALL populate_t1();
 
 SELECT COUNT(*) FROM t1;
 
+--enable_info
 CREATE INDEX idx_title ON t1(title);
+--disable_info
 
---source include/restart_mysqld.inc
-
-CHECK TABLE t1;
-
-SELECT * FROM t1 WHERE title = 'a10';
-
-SELECT * FROM t1 WHERE title = 'a5000';
-
-SELECT * FROM t1 WHERE title = 'a10000';
-
-SELECT * FROM t1 WHERE title = 'a10010';
-
-DROP TABLE t1;
+RENAME TABLE t1 TO t0;
 
 -- echo # Test Blob
 
@@ -104,16 +85,32 @@ INSERT INTO t1 VALUES
 
 SELECT CHAR_LENGTH(b) FROM t1;
 
-ALTER TABLE t1 DROP COLUMN c;
+--enable_info
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+--disable_info
 
 --source include/restart_mysqld.inc
 
-CHECK TABLE t1;
+CHECK TABLE t0,t1;
 
 SELECT CHAR_LENGTH(b) FROM t1;
 
 DROP TABLE t1;
 
+RENAME TABLE t0 to t1;
+
+CHECK TABLE t1;
+
+SELECT * FROM t1 WHERE title = 'a10';
+
+SELECT * FROM t1 WHERE title = 'a5000';
+
+SELECT * FROM t1 WHERE title = 'a10000';
+
+SELECT * FROM t1 WHERE title = 'a10010';
+
+DROP TABLE t1;
+
 # Test Crash Recovery
 
 if ($row_format != 'COMPRESSED')
@@ -140,17 +137,16 @@ if ($row_format == 'COMPRESSED')
 CALL populate_t1();
 -- enable_query_log
 
-SET debug_dbug='+d,crash_commit_before';
-
-# Write file to make mysql-test-run.pl start up the server again
---exec echo "restart" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
-
---error 2013
+connect (hang,localhost,root);
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+send
 CREATE INDEX idx_title ON t1(title);
 
---enable_reconnect
---source include/wait_until_connected_again.inc
---disable_reconnect
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+let $shutdown_timeout=0;
+--source include/restart_mysqld.inc
+disconnect hang;
 
 SELECT COUNT(*) FROM t1;
 
@@ -194,17 +190,16 @@ INSERT INTO t1 VALUES
 
 SELECT CHAR_LENGTH(b) FROM t1;
 
-SET debug_dbug='+d,crash_commit_before';
+connect (hang,localhost,root);
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+send
+ALTER TABLE t1 DROP COLUMN c, FORCE;
 
-# Write file to make mysql-test-run.pl start up the server again
---exec echo "restart" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
-
---error 2013
-ALTER TABLE t1 DROP COLUMN c;
-
---enable_reconnect
---source include/wait_until_connected_again.inc
---disable_reconnect
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+--source include/restart_mysqld.inc
+disconnect hang;
+let $shutdown_timeout=60;
 
 CHECK TABLE t1;
 
@@ -212,10 +207,4 @@ SELECT CHAR_LENGTH(b) FROM t1;
 
 DROP TABLE t1;
 
-# Restore global variables
-if ($row_format == 'COMPRESSED')
-{
-  SET GLOBAL innodb_file_per_table=default;
-}
-
 DROP PROCEDURE populate_t1;
diff --git a/mysql-test/suite/innodb/r/alter_copy.result b/mysql-test/suite/innodb/r/alter_copy.result
index 286c5152ded..659b8ae03b0 100644
--- a/mysql-test/suite/innodb/r/alter_copy.result
+++ b/mysql-test/suite/innodb/r/alter_copy.result
@@ -37,7 +37,9 @@ t1	CREATE TABLE `t1` (
   FULLTEXT KEY `b_2` (`b`,`c`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 ALTER TABLE t1 FORCE, ALGORITHM=COPY;
-SET DEBUG_DBUG='+d,crash_commit_before';
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_copy_trans_commit SIGNAL hung WAIT_FOR ever';
+# create 32 secondary indexes
 ALTER TABLE t ADD INDEX(b,c,d,a),ADD INDEX(b,c,a,d),ADD INDEX(b,a,c,d),ADD INDEX(b,a,d,c),
 ADD INDEX(b,d,a,c),ADD INDEX(b,d,c,a),ADD INDEX(a,b,c,d),ADD INDEX(a,b,d,c),
 ADD INDEX(a,c,b,d),ADD INDEX(a,c,d,b),ADD INDEX(a,d,b,c),ADD INDEX(a,d,c,b),
@@ -47,7 +49,9 @@ ADD INDEX(d,b,a,c),ADD INDEX(d,b,c,a),ADD INDEX(d,c,a,b),ADD INDEX(d,c,b,a),
 ADD INDEX(a,b,c), ADD INDEX(a,c,b), ADD INDEX(a,c,d), ADD INDEX(a,d,c),
 ADD INDEX(a,b,d), ADD INDEX(a,d,b), ADD INDEX(b,c,d), ADD INDEX(b,d,c),
 ALGORITHM=COPY;
-ERROR HY000: Lost connection to MySQL server during query
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 #sql-temporary.frm
 #sql-temporary.ibd
 FTS_INDEX_1.ibd
diff --git a/mysql-test/suite/innodb/r/innodb_bulk_create_index_debug.result b/mysql-test/suite/innodb/r/innodb_bulk_create_index_debug.result
index cd5a3c340da..295a9f1bed8 100644
--- a/mysql-test/suite/innodb/r/innodb_bulk_create_index_debug.result
+++ b/mysql-test/suite/innodb/r/innodb_bulk_create_index_debug.result
@@ -17,21 +17,9 @@ SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
 CREATE INDEX idx_title ON t1(title);
-CHECK TABLE t1;
-Table	Op	Msg_type	Msg_text
-test.t1	check	status	OK
-SELECT * FROM t1 WHERE title = 'a10';
-class	id	title
-10	10	a10
-SELECT * FROM t1 WHERE title = 'a5000';
-class	id	title
-5000	5000	a5000
-SELECT * FROM t1 WHERE title = 'a10000';
-class	id	title
-10000	10000	a10000
-SELECT * FROM t1 WHERE title = 'a10010';
-class	id	title
-DROP TABLE t1;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+RENAME TABLE t1 TO t0;
 # Test Blob
 CREATE TABLE t1(
 a INT PRIMARY KEY,
@@ -48,9 +36,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-ALTER TABLE t1 DROP COLUMN c;
-CHECK TABLE t1;
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+CHECK TABLE t0,t1;
 Table	Op	Msg_type	Msg_text
+test.t0	check	status	OK
 test.t1	check	status	OK
 SELECT CHAR_LENGTH(b) FROM t1;
 CHAR_LENGTH(b)
@@ -59,14 +50,33 @@ CHAR_LENGTH(b)
 40000
 60000
 DROP TABLE t1;
+RENAME TABLE t0 to t1;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SELECT * FROM t1 WHERE title = 'a10';
+class	id	title
+10	10	a10
+SELECT * FROM t1 WHERE title = 'a5000';
+class	id	title
+5000	5000	a5000
+SELECT * FROM t1 WHERE title = 'a10000';
+class	id	title
+10000	10000	a10000
+SELECT * FROM t1 WHERE title = 'a10010';
+class	id	title
+DROP TABLE t1;
 CREATE TABLE t1(
 class   INT,
 id      INT,
 title   VARCHAR(100)
 ) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
-SET debug_dbug='+d,crash_commit_before';
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
 CREATE INDEX idx_title ON t1(title);
-ERROR HY000: Lost connection to MySQL server during query
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
@@ -104,9 +114,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-SET debug_dbug='+d,crash_commit_before';
-ALTER TABLE t1 DROP COLUMN c;
-ERROR HY000: Lost connection to MySQL server during query
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
@@ -137,21 +150,9 @@ SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
 CREATE INDEX idx_title ON t1(title);
-CHECK TABLE t1;
-Table	Op	Msg_type	Msg_text
-test.t1	check	status	OK
-SELECT * FROM t1 WHERE title = 'a10';
-class	id	title
-10	10	a10
-SELECT * FROM t1 WHERE title = 'a5000';
-class	id	title
-5000	5000	a5000
-SELECT * FROM t1 WHERE title = 'a10000';
-class	id	title
-10000	10000	a10000
-SELECT * FROM t1 WHERE title = 'a10010';
-class	id	title
-DROP TABLE t1;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+RENAME TABLE t1 TO t0;
 # Test Blob
 CREATE TABLE t1(
 a INT PRIMARY KEY,
@@ -168,9 +169,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-ALTER TABLE t1 DROP COLUMN c;
-CHECK TABLE t1;
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+CHECK TABLE t0,t1;
 Table	Op	Msg_type	Msg_text
+test.t0	check	status	OK
 test.t1	check	status	OK
 SELECT CHAR_LENGTH(b) FROM t1;
 CHAR_LENGTH(b)
@@ -179,14 +183,33 @@ CHAR_LENGTH(b)
 40000
 60000
 DROP TABLE t1;
+RENAME TABLE t0 to t1;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SELECT * FROM t1 WHERE title = 'a10';
+class	id	title
+10	10	a10
+SELECT * FROM t1 WHERE title = 'a5000';
+class	id	title
+5000	5000	a5000
+SELECT * FROM t1 WHERE title = 'a10000';
+class	id	title
+10000	10000	a10000
+SELECT * FROM t1 WHERE title = 'a10010';
+class	id	title
+DROP TABLE t1;
 CREATE TABLE t1(
 class   INT,
 id      INT,
 title   VARCHAR(100)
 ) ENGINE=InnoDB ROW_FORMAT=COMPACT;
-SET debug_dbug='+d,crash_commit_before';
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
 CREATE INDEX idx_title ON t1(title);
-ERROR HY000: Lost connection to MySQL server during query
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
@@ -224,9 +247,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-SET debug_dbug='+d,crash_commit_before';
-ALTER TABLE t1 DROP COLUMN c;
-ERROR HY000: Lost connection to MySQL server during query
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
@@ -257,21 +283,9 @@ SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
 CREATE INDEX idx_title ON t1(title);
-CHECK TABLE t1;
-Table	Op	Msg_type	Msg_text
-test.t1	check	status	OK
-SELECT * FROM t1 WHERE title = 'a10';
-class	id	title
-10	10	a10
-SELECT * FROM t1 WHERE title = 'a5000';
-class	id	title
-5000	5000	a5000
-SELECT * FROM t1 WHERE title = 'a10000';
-class	id	title
-10000	10000	a10000
-SELECT * FROM t1 WHERE title = 'a10010';
-class	id	title
-DROP TABLE t1;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+RENAME TABLE t1 TO t0;
 # Test Blob
 CREATE TABLE t1(
 a INT PRIMARY KEY,
@@ -288,9 +302,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-ALTER TABLE t1 DROP COLUMN c;
-CHECK TABLE t1;
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+CHECK TABLE t0,t1;
 Table	Op	Msg_type	Msg_text
+test.t0	check	status	OK
 test.t1	check	status	OK
 SELECT CHAR_LENGTH(b) FROM t1;
 CHAR_LENGTH(b)
@@ -299,14 +316,33 @@ CHAR_LENGTH(b)
 40000
 60000
 DROP TABLE t1;
+RENAME TABLE t0 to t1;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SELECT * FROM t1 WHERE title = 'a10';
+class	id	title
+10	10	a10
+SELECT * FROM t1 WHERE title = 'a5000';
+class	id	title
+5000	5000	a5000
+SELECT * FROM t1 WHERE title = 'a10000';
+class	id	title
+10000	10000	a10000
+SELECT * FROM t1 WHERE title = 'a10010';
+class	id	title
+DROP TABLE t1;
 CREATE TABLE t1(
 class   INT,
 id      INT,
 title   VARCHAR(100)
 ) ENGINE=InnoDB ROW_FORMAT=DYNAMIC;
-SET debug_dbug='+d,crash_commit_before';
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
 CREATE INDEX idx_title ON t1(title);
-ERROR HY000: Lost connection to MySQL server during query
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
@@ -344,9 +380,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-SET debug_dbug='+d,crash_commit_before';
-ALTER TABLE t1 DROP COLUMN c;
-ERROR HY000: Lost connection to MySQL server during query
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
@@ -378,21 +417,9 @@ SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
 CREATE INDEX idx_title ON t1(title);
-CHECK TABLE t1;
-Table	Op	Msg_type	Msg_text
-test.t1	check	status	OK
-SELECT * FROM t1 WHERE title = 'a10';
-class	id	title
-10	10	a10
-SELECT * FROM t1 WHERE title = 'a5000';
-class	id	title
-5000	5000	a5000
-SELECT * FROM t1 WHERE title = 'a10000';
-class	id	title
-10000	10000	a10000
-SELECT * FROM t1 WHERE title = 'a10010';
-class	id	title
-DROP TABLE t1;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+RENAME TABLE t1 TO t0;
 # Test Blob
 SET GLOBAL innodb_file_per_table=1;
 CREATE TABLE t1(
@@ -410,9 +437,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-ALTER TABLE t1 DROP COLUMN c;
-CHECK TABLE t1;
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+affected rows: 0
+info: Records: 0  Duplicates: 0  Warnings: 0
+CHECK TABLE t0,t1;
 Table	Op	Msg_type	Msg_text
+test.t0	check	status	OK
 test.t1	check	status	OK
 SELECT CHAR_LENGTH(b) FROM t1;
 CHAR_LENGTH(b)
@@ -421,15 +451,34 @@ CHAR_LENGTH(b)
 40000
 60000
 DROP TABLE t1;
+RENAME TABLE t0 to t1;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SELECT * FROM t1 WHERE title = 'a10';
+class	id	title
+10	10	a10
+SELECT * FROM t1 WHERE title = 'a5000';
+class	id	title
+5000	5000	a5000
+SELECT * FROM t1 WHERE title = 'a10000';
+class	id	title
+10000	10000	a10000
+SELECT * FROM t1 WHERE title = 'a10010';
+class	id	title
+DROP TABLE t1;
 SET GLOBAL innodb_file_per_table=1;
 CREATE TABLE t1(
 class   INT,
 id      INT,
 title   VARCHAR(100)
 ) ENGINE=InnoDB ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=4;
-SET debug_dbug='+d,crash_commit_before';
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
 CREATE INDEX idx_title ON t1(title);
-ERROR HY000: Lost connection to MySQL server during query
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 SELECT COUNT(*) FROM t1;
 COUNT(*)
 10000
@@ -468,9 +517,12 @@ CHAR_LENGTH(b)
 20000
 40000
 60000
-SET debug_dbug='+d,crash_commit_before';
-ALTER TABLE t1 DROP COLUMN c;
-ERROR HY000: Lost connection to MySQL server during query
+connect  hang,localhost,root;
+SET DEBUG_SYNC='alter_table_inplace_trans_commit SIGNAL hung WAIT_FOR ever';
+ALTER TABLE t1 DROP COLUMN c, FORCE;
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+disconnect hang;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
@@ -481,5 +533,4 @@ CHAR_LENGTH(b)
 40000
 60000
 DROP TABLE t1;
-SET GLOBAL innodb_file_per_table=default;
 DROP PROCEDURE populate_t1;
diff --git a/mysql-test/suite/innodb/t/alter_copy.test b/mysql-test/suite/innodb/t/alter_copy.test
index 0dce61994b5..b7ab05a061a 100644
--- a/mysql-test/suite/innodb/t/alter_copy.test
+++ b/mysql-test/suite/innodb/t/alter_copy.test
@@ -37,11 +37,11 @@ SELECT * FROM t1 WHERE MATCH(b,c) AGAINST ('column');
 SHOW CREATE TABLE t1;
 ALTER TABLE t1 FORCE, ALGORITHM=COPY;
 
-# crash right after the last write_row(), before the first commit of ALTER TABLE
---source include/expect_crash.inc
+# kill right after the last write_row(), before the first commit of ALTER TABLE
+connect (hang,localhost,root);
 
-SET DEBUG_DBUG='+d,crash_commit_before';
---error 2013
+SET DEBUG_SYNC='alter_table_copy_trans_commit SIGNAL hung WAIT_FOR ever';
+send
 # create 32 secondary indexes
 ALTER TABLE t ADD INDEX(b,c,d,a),ADD INDEX(b,c,a,d),ADD INDEX(b,a,c,d),ADD INDEX(b,a,d,c),
               ADD INDEX(b,d,a,c),ADD INDEX(b,d,c,a),ADD INDEX(a,b,c,d),ADD INDEX(a,b,d,c),
@@ -53,8 +53,13 @@ ALTER TABLE t ADD INDEX(b,c,d,a),ADD INDEX(b,c,a,d),ADD INDEX(b,a,c,d),ADD INDEX
               ADD INDEX(a,b,d), ADD INDEX(a,d,b), ADD INDEX(b,c,d), ADD INDEX(b,d,c),
  	      ALGORITHM=COPY;
 
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR hung';
+let $shutdown_timeout=0;
 --let $restart_parameters= --innodb-force-recovery=3
---source include/start_mysqld.inc
+--source include/restart_mysqld.inc
+disconnect hang;
+let $shutdown_timeout=;
 let $datadir=`select @@datadir`;
 --replace_regex /#sql-[0-9a-f_]*/#sql-temporary/ /FTS_[0-9a-f]*_[0-9a-f]*/FTS/
 --list_files $datadir/test
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 41f62de2a70..9d7e03727d3 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -9788,6 +9788,7 @@ end_temporary:
 	      (ulong) (copied + deleted), (ulong) deleted,
 	      (ulong) thd->get_stmt_da()->current_statement_warn_count());
   my_ok(thd, copied + deleted, 0L, alter_ctx.tmp_name);
+  DEBUG_SYNC(thd, "alter_table_inplace_trans_commit");
   DBUG_RETURN(false);
 
 err_new_table_cleanup:
@@ -9889,12 +9890,14 @@ bool mysql_trans_commit_alter_copy_data(THD *thd)
   uint save_unsafe_rollback_flags;
   DBUG_ENTER("mysql_trans_commit_alter_copy_data");
 
-  /* Save flags as transcommit_implicit_are_deleting_them */
+  /* Save flags as trans_commit_implicit are deleting them */
   save_unsafe_rollback_flags= thd->transaction.stmt.m_unsafe_rollback_flags;
 
+  DEBUG_SYNC(thd, "alter_table_copy_trans_commit");
+
   if (ha_enable_transaction(thd, TRUE))
     DBUG_RETURN(TRUE);
-  
+
   /*
     Ensure that the new table is saved properly to disk before installing
     the new .frm.