MDEV 15532 Assertion `!log->same_pk' failed in row_log_table_apply_delete

The reason for the failure is that
thd->mdl_context.release_transactional_locks()
was called after commit & rollback even in cases where the current
transaction is still active.

For 10.2, 10.3 and 10.4 the fix is simple:
- Replace all calls to thd->mdl_context.release_transactional_locks() with
  thd->release_transactional_locks(). The thd function will only call
  the mdl_context function if there are no active transactional locks.
  In 10.6 we will better fix where we will change the return value for
  some trans_xxx() functions to indicate if transaction did close the
  transaction or not. This will avoid the need of the indirect call.

Other things:
- trans_xa_commit() and trans_xa_rollback() will automatically
  call release_transactional_locks() if the transaction is closed.
- We can't do that for the other functions as the caller of many of these
  are doing additional work (like close_thread_tables) before calling
  release_transactional_locks().
- Added missing abort_result_set() and missing DBUG_RETURN in
  select_create::send_eof()
- Fixed wrong indentation in injector::transaction::commit()

1 files changed, 3 insertions, 3 deletions

diff --git a/sql/log_event.cc b/sql/log_event.cc
index 097cbe8da9d..c649e1f64fa 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -7150,10 +7150,10 @@ error:
   if (thd->transaction_rollback_request)
   {
     trans_rollback_implicit(thd);
-    thd->mdl_context.release_transactional_locks();
+    thd->release_transactional_locks();
   }
   else if (! thd->in_multi_stmt_transaction_mode())
-    thd->mdl_context.release_transactional_locks();
+    thd->release_transactional_locks();
   else
     thd->mdl_context.release_statement_locks();
 
@@ -8554,7 +8554,7 @@ int Xid_log_event::do_apply_event(rpl_group_info *rgi)
                     "COMMIT /* implicit, from Xid_log_event */");
   thd->variables.option_bits&= ~OPTION_GTID_BEGIN;
   res= trans_commit(thd); /* Automatically rolls back on error. */
-  thd->mdl_context.release_transactional_locks();
+  thd->release_transactional_locks();
 
 #ifdef WITH_WSREP
   if (WSREP(thd)) mysql_mutex_lock(&thd->LOCK_thd_data);