Backport of revno: 2617.80.1

Also re-enables the test for Bug #43867

Followup to Bug#46654 False deadlock on concurrent DML/DDL with partitions, 
                      inconsistent behavior

Partition_sync.test uses features only available in debug builds.
Disabling the test for non-debug builds.

mysql-test/r/partition_sync.result

-# Disabled until Bug#46654 False deadlock on concurrent DML/DDL 
-# with partitions, inconsistent behavior is backported
+#
+# Bug #43867 ALTER TABLE on a partitioned table 
+#            causes unnecessary deadlocks
+#
+CREATE TABLE t1 (a int) PARTITION BY RANGE (a)
+(PARTITION p0 VALUES LESS THAN (1),
+PARTITION p1 VALUES LESS THAN (2));
+INSERT INTO t1 VALUES (0),(1);
+# Connection 2
+BEGIN;
+SELECT * FROM t1;
+a
+0
+1
+# Connection 1
+ALTER TABLE t1 DROP PARTITION p3;
+ERROR HY000: Error in list of partitions to DROP
+# Connection 2
+# This failed with deadlock and should not do so.
+SELECT * FROM t1;
+a
+0
+1
+# Connection 1
+DROP TABLE t1;
 #
 # Bug #46654 False deadlock on concurrent DML/DDL 
 #            with partitions, inconsistent behavior

mysql-test/t/partition_sync.test

 --source include/have_partition.inc
+--source include/have_debug.inc
 # Save the initial number of concurrent sessions.
 --source include/count_sessions.inc
 
---echo # Disabled until Bug#46654 False deadlock on concurrent DML/DDL 
---echo # with partitions, inconsistent behavior is backported
-
-#--echo #
-#--echo # Bug #43867 ALTER TABLE on a partitioned table 
-#--echo #            causes unnecessary deadlocks
-#--echo #
-#
-#CREATE TABLE t1 (a int) PARTITION BY RANGE (a)
-#(PARTITION p0 VALUES LESS THAN (1),
-# PARTITION p1 VALUES LESS THAN (2));
-#
-#INSERT INTO t1 VALUES (0),(1);
-#
-#connect(con1,localhost,root);
-#
-#--echo # Connection 2
-#connection con1;
-#BEGIN;
-#SELECT * FROM t1;
-#
-#--echo # Connection 1
-#connection default;
-#--error ER_DROP_PARTITION_NON_EXISTENT
-#ALTER TABLE t1 DROP PARTITION p3;
-#
-#--echo # Connection 2
-#connection con1;
-#--echo # This failed with deadlock and should not do so.
-#SELECT * FROM t1;
-#
-#--echo # Connection 1
-#connection default;
-#disconnect con1;
-#DROP TABLE t1;
+--echo #
+--echo # Bug #43867 ALTER TABLE on a partitioned table 
+--echo #            causes unnecessary deadlocks
+--echo #
+
+CREATE TABLE t1 (a int) PARTITION BY RANGE (a)
+(PARTITION p0 VALUES LESS THAN (1),
+ PARTITION p1 VALUES LESS THAN (2));
+
+INSERT INTO t1 VALUES (0),(1);
+
+connect(con1,localhost,root);
+
+--echo # Connection 2
+connection con1;
+BEGIN;
+SELECT * FROM t1;
+
+--echo # Connection 1
+connection default;
+--error ER_DROP_PARTITION_NON_EXISTENT
+ALTER TABLE t1 DROP PARTITION p3;
+
+--echo # Connection 2
+connection con1;
+--echo # This failed with deadlock and should not do so.
+SELECT * FROM t1;
+
+--echo # Connection 1
+connection default;
+disconnect con1;
+DROP TABLE t1;
 
 
 --echo #