Bug #10942 "deadlock with FLUSH TABLES WITH READ LOCK + STOP SLAVE"

don't allow STOP SLAVE if global read lock is in taken

mysql-test/r/rpl_flush_tables.result

@@ -38,3 +38,9 @@ master-bin.000001	461	Query	1	461	use `test`; rename table t1 to t5, t2 to t1
 master-bin.000001	527	Query	1	527	use `test`; flush tables
 select * from t3;
 a
+stop slave;
+drop table t1;
+flush tables with read lock;
+start slave;
+stop slave;
+ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction

mysql-test/t/rpl_flush_tables.test

@@ -37,4 +37,14 @@ select * from t3;
 # Note that all this confusion may cause warnings 'table xx is open on rename'
 # in the .err files; these are not fatal and are not reported by mysql-test-run.
 
+stop slave;
+connection master;
+drop table t1;
+connection slave;
+flush tables with read lock;
+start slave;
+sleep 1;
+--error 1192
+stop slave;
+
 # End of 4.1 tests

sql/sql_parse.cc

@@ -2601,7 +2601,7 @@ mysql_execute_command(THD *thd)
     To prevent that, refuse SLAVE STOP if the
     client thread has locked tables
   */
-  if (thd->locked_tables || thd->active_transaction())
+  if (thd->locked_tables || thd->active_transaction() || thd->global_read_lock)
   {
     send_error(thd,ER_LOCK_OR_ACTIVE_TRANSACTION);
     break;