BUG20653441: Fix connection hanging when a query is killed

Extra patch to fix the "Unread result found" error caused when
a query is killed and cursor.close() is called subsequently.

Author: peeyushgupta

lib/mysql/connector/connection.py

@@ -437,11 +437,15 @@ def get_rows(self, count=None, binary=False, columns=None):
         if not self.unread_result:
             raise errors.InternalError("No result set available.")
 
-        if binary:
-            rows = self._protocol.read_binary_result(
-                self._socket, columns, count)
-        else:
-            rows = self._protocol.read_text_result(self._socket, count)
+        try:
+            if binary:
+                rows = self._protocol.read_binary_result(
+                    self._socket, columns, count)
+            else:
+                rows = self._protocol.read_text_result(self._socket, count)
+        except errors.Error as err:
+            self.unread_result = False
+            raise err
         if rows[-1] is not None:
             self._handle_server_status(rows[-1]['status_flag'])
             self.unread_result = False

lib/mysql/connector/connection_cext.py

@@ -269,6 +269,7 @@ def get_rows(self, count=None, binary=False, columns=None):
                     break
                 row = self._cmysql.fetch_row()
         except MySQLInterfaceError as exc:
+            self.free_result()
             raise errors.get_mysql_exception(msg=exc.msg, errno=exc.errno,
                                              sqlstate=exc.sqlstate)
 

tests/test_bugs.py

@@ -3645,6 +3645,7 @@ def sleepy_select(cnx):
                 cur.fetchall()
             except errors.Error as err:
                 cnx.test_error = err
+                cur.close()
 
         worker = Thread(target=sleepy_select, args=[self.cnx])
         killer = Thread(target=kill, args=[self.cnx.connection_id])