BUG19549363: Raise error when compression used with reset_session

peeyushgupta · peeyushgupta · commit 1b412b74e1f4 · 2014-10-10T18:01:53.000+05:30
Change user command raises packets out of order error when used with
compression. This causes error when a pooled connection tries to
reset session which internally sends change user command for MySQL
server 5.7.2 or earlier. We fix this by raising a NotSupportedError
whenever someone tries to reset a session on MySQL server earlier
than 5.7.3.

A test case has been added for BUG#19549363.
diff --git a/lib/mysql/connector/connection.py b/lib/mysql/connector/connection.py
@@ -123,6 +123,7 @@ def __init__(self, *args, **kwargs):
         self._ssl_active = False
         self._auth_plugin = None
         self._pool_config_version = None
+        self._compress = False
 
         if len(kwargs) > 0:
             self.connect(**kwargs)
@@ -271,6 +272,7 @@ def config(self, **kwargs):
 
         try:
             if config['compress']:
+                self._compress = True
                 self.set_client_flags([ClientFlag.COMPRESS])
         except KeyError:
             pass  # Missing compress argument is OK
@@ -884,6 +886,10 @@ def cmd_change_user(self, username='', password='', database='',
         if self.unread_result:
             raise errors.InternalError("Unread result found.")
 
+        if self._compress:
+            raise errors.NotSupportedError("Change user is not supported with "
+                                           "compression.")
+
         packet = self._protocol.make_change_user(
             handshake=self._handshake,
             username=username, password=password, database=database,
@@ -943,8 +949,13 @@ def reset_session(self, user_variables=None, session_variables=None):
         try:
             self.cmd_reset_connection()
         except errors.NotSupportedError:
-            self.cmd_change_user(self._user, self._password,
-                                 self._database, self._charset_id)
+            if self._compress:
+                raise errors.NotSupportedError(
+                    "Reset session is not supported with compression for "
+                    "MySQL server version 5.7.2 or earlier.")
+            else:
+                self.cmd_change_user(self._user, self._password,
+                                     self._database, self._charset_id)
 
         cur = self.cursor()
         if user_variables:
diff --git a/lib/mysql/connector/pooling.py b/lib/mysql/connector/pooling.py
@@ -269,6 +269,17 @@ def add_connection(self, cnx=None):
 
             if not cnx:
                 cnx = MySQLConnection(**self._cnx_config)
+                try:
+                    if (self._reset_session and self._cnx_config['compress']
+                            and cnx.get_server_version() < (5, 7, 3)):
+                        raise errors.NotSupportedError("Pool reset session is "
+                                                       "not supported with "
+                                                       "compression for MySQL "
+                                                       "server version 5.7.2 "
+                                                       "or earlier.")
+                except KeyError:
+                    pass
+
                 # pylint: disable=W0201,W0212
                 cnx._pool_config_version = self._config_version
                 # pylint: enable=W0201,W0212
diff --git a/tests/test_bugs.py b/tests/test_bugs.py
@@ -3005,3 +3005,25 @@ def test_binary_charset(self):
 
         self.cur.execute("SELECT * FROM {0}".format(self.tbl))
         self.assertEqual(exp, self.cur.fetchall())
+
+
+@unittest.skipIf(tests.MYSQL_VERSION < (5, 7, 3),
+                 "MySQL {0} does not support COM_RESET_CONNECTION".format(
+                 tests.MYSQL_VERSION_TXT))
+class BugOra19549363(tests.MySQLConnectorTests):
+    """BUG#19549363: Compression does not work with Change User
+    """
+    def test_compress(self):
+        config = tests.get_mysql_config()
+        config['compress'] = True
+
+        mysql.connector._CONNECTION_POOLS = {}
+        config['pool_name'] = 'mypool'
+        config['pool_size'] = 3
+        config['pool_reset_session'] = True
+        cnx1 = mysql.connector.connect(**config)
+
+        try:
+            cnx1.close()
+        except:
+            self.fail("Reset session with compression test failed.")
