Fix for CONPY123: Free pending result sets when closing cursor

When using text protocol pending result sets weren't properly freed,
so executing another command on the same connection resulted in an error
"commands out of sync".

Author: 9EOR9

mariadb/mariadb_cursor.c

@@ -403,7 +403,11 @@ static void MrdbCursor_clear_result(MrdbCursor *self)
         /* clear pending result sets */
         if (self->connection->mysql)
         {
-            while (!mysql_next_result(self->connection->mysql));
+            do {
+                MYSQL_RES *res;
+                if ((res= mysql_use_result(self->connection->mysql)))
+                    mysql_free_result(res);
+            } while (!mysql_next_result(self->connection->mysql));
         }
     }
     /* CONPY-52: Avoid possible double free */
@@ -480,6 +484,7 @@ void ma_cursor_close(MrdbCursor *self)
 {
     if (!self->is_closed)
     {
+        MrdbCursor_clear_result(self);
         if (!self->is_text && self->stmt)
         {
             /* Todo: check if all the cursor stuff is deleted (when using prepared

testing/test/integration/test_cursor.py

@@ -1042,6 +1042,18 @@ def test_conpy68(self):
         self.assertEqual(row[0], json.dumps(content))
         del cursor
 
+    def test_conpy123(self):
+        con= create_connection({"client_flag" : CLIENT.MULTI_STATEMENTS})
+        cursor1= con.cursor()
+        cursor1.execute("SELECT 1; SELECT 2")
+        cursor1.close()
+        cursor2= con.cursor()
+        cursor2.execute("SELECT 1")
+        row= cursor2.fetchone()
+        self.assertEqual(row[0], 1)
+        cursor2.close()
+        con.close()
+
     def test_conpy103(self):
         con= create_connection()
         cursor= con.cursor()