Bug#45548: XA transaction without access to InnoDB tables crashes the server

The problem is that the one phase commit function failed to
properly end a empty transaction. The solution is to ensure
that the transaction cleanup procedure is invoked even for
empty transactions.

mysql-test/r/xa.result:
  Add test case result for Bug#45548
mysql-test/t/xa.test:
  Add test case for Bug#45548
sql/handler.cc:
  Invoke transaction cleanup function whenever a transaction is ended.

mysql-test/r/xa.result

@@ -81,3 +81,11 @@ xa rollback 'a';
 xa start 'a';
 xa end 'a';
 xa rollback 'a';
+xa start 'a';
+xa end 'a';
+xa prepare 'a';
+xa commit 'a';
+xa start 'a';
+xa end 'a';
+xa prepare 'a';
+xa commit 'a';

mysql-test/t/xa.test

@@ -135,6 +135,20 @@ xa start 'a';
 xa end 'a';
 xa rollback 'a';
 
+#
+# Bug#45548: XA transaction without access to InnoDB tables crashes the server
+#
+
+xa start 'a';
+xa end 'a';
+xa prepare 'a';
+xa commit 'a';
+
+xa start 'a';
+xa end 'a';
+xa prepare 'a';
+xa commit 'a';
+
 # Wait till all disconnects are completed
 --source include/wait_until_count_sessions.inc
 

sql/handler.cc

@@ -1242,9 +1242,10 @@ int ha_commit_one_phase(THD *thd, bool all)
 #endif
       thd->variables.tx_isolation=thd->session_tx_isolation;
     }
-    if (is_real_trans)
-      thd->transaction.cleanup();
   }
+  /* Free resources and perform other cleanup even for 'empty' transactions. */
+  if (is_real_trans)
+    thd->transaction.cleanup();
 #endif /* USING_TRANSACTIONS */
   DBUG_RETURN(error);
 }