Bug#11853126 RE-ENABLE CONCURRENT READS WHILE CREATING

SECONDARY INDEX IN INNODB

This is a follow-up patch.

This patch moves part of the new test coverage to a test
file that is only run on debug builds since it used debug-
only features and therefore broke the test case on
release builds.

mysql-test/t/innodb_mysql_sync.test

@@ -2,6 +2,7 @@
 # Test file for InnoDB tests that require the debug sync facility
 #
 --source include/have_innodb.inc
+--source include/have_debug.inc
 --source include/have_debug_sync.inc
 # Save the initial number of concurrent sessions.
 --source include/count_sessions.inc
@@ -277,6 +278,32 @@ SET DEBUG_SYNC= "RESET";
 DROP TABLE t1;
 
 
+--echo #
+--echo # Bug#11853126 RE-ENABLE CONCURRENT READS WHILE CREATING SECONDARY INDEX
+--echo #              IN INNODB
+--echo #
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1(a INT NOT NULL, b INT NOT NULL) engine=innodb;
+INSERT INTO t1 VALUES (1, 12345), (2, 23456);
+
+--echo # Connection con1
+--connect (con1,localhost,root)
+SET SESSION debug= "+d,alter_table_rollback_new_index";
+--error ER_UNKNOWN_ERROR
+ALTER TABLE t1 ADD PRIMARY KEY(a);
+SELECT * FROM t1;
+
+--echo # Connection default
+--connection default
+SELECT * FROM t1;
+DROP TABLE t1;
+disconnect con1;
+
+
 # Check that all connections opened by test cases in this file are really
 # gone so execution of other tests won't be affected by their presence.
 --source include/wait_until_count_sessions.inc