Fix for bug #26288: savepoint not deleted, comit on empty transaction

Problem: commit doesn't delete savepoints if there are no changes 
in the transaction.

Fix: delete them in such cases.

mysql-test/r/innodb_mysql.result

@@ -1267,4 +1267,28 @@ CREATE INDEX i1 on t1 (a(3));
 SELECT * FROM t1 WHERE a = 'abcde';
 a
 DROP TABLE t1;
+#
+# BUG #26288: savepoint are not deleted on comit, if the transaction 
+# was otherwise empty
+#
+BEGIN;
+SAVEPOINT s1;
+COMMIT;
+RELEASE SAVEPOINT s1;
+ERROR 42000: SAVEPOINT s1 does not exist
+BEGIN;
+SAVEPOINT s2;
+COMMIT;
+ROLLBACK TO SAVEPOINT s2;
+ERROR 42000: SAVEPOINT s2 does not exist
+BEGIN;
+SAVEPOINT s3;
+ROLLBACK;
+RELEASE SAVEPOINT s3;
+ERROR 42000: SAVEPOINT s3 does not exist
+BEGIN;
+SAVEPOINT s4;
+ROLLBACK;
+ROLLBACK TO SAVEPOINT s4;
+ERROR 42000: SAVEPOINT s4 does not exist
 End of 5.0 tests

mysql-test/t/innodb_mysql.test

@@ -1025,4 +1025,33 @@ CREATE INDEX i1 on t1 (a(3));
 SELECT * FROM t1 WHERE a = 'abcde'; 
 DROP TABLE t1;
 
+
+--echo #
+--echo # BUG #26288: savepoint are not deleted on comit, if the transaction 
+--echo # was otherwise empty
+--echo #
+BEGIN;
+SAVEPOINT s1;
+COMMIT;
+--error 1305
+RELEASE SAVEPOINT s1;
+
+BEGIN;
+SAVEPOINT s2;
+COMMIT;
+--error 1305
+ROLLBACK TO SAVEPOINT s2;
+
+BEGIN;
+SAVEPOINT s3;
+ROLLBACK;
+--error 1305
+RELEASE SAVEPOINT s3;
+
+BEGIN;
+SAVEPOINT s4;
+ROLLBACK;
+--error 1305
+ROLLBACK TO SAVEPOINT s4;
+
 --echo End of 5.0 tests

sql/handler.cc

@@ -730,6 +730,16 @@ int ha_commit_trans(THD *thd, bool all)
     if (is_real_trans)
       start_waiting_global_read_lock(thd);
   }
+  else if (all)
+  {
+    /*
+      A COMMIT of an empty transaction. There may be savepoints.
+      Destroy them. If the transaction is not empty
+      savepoints are cleared in ha_commit_one_phase()
+      or ha_rollback_trans().
+    */
+    thd->transaction.cleanup();
+  }
 #endif /* USING_TRANSACTIONS */
   DBUG_RETURN(error);
 }
@@ -825,11 +835,11 @@ int ha_rollback_trans(THD *thd, bool all)
         thd->transaction.xid_state.xid.null();
     }
     if (all)
-    {
       thd->variables.tx_isolation=thd->session_tx_isolation;
-      thd->transaction.cleanup();
-    }
   }
+  /* Always cleanup. Even if there nht==0. There may be savepoints. */
+  if (all)
+    thd->transaction.cleanup();
 #endif /* USING_TRANSACTIONS */
   if (all)
     thd->transaction_rollback_request= FALSE;