BUG25558885: Set default connection timeout to pure connector/python

With any long running queries, the cext connector/python would lose
connection to the server with the message:
ERROR 2013 (LOST CONNECTION TO MYSQL SERVER)

But the pure connector/python does not throw any such error.

To make the behaviour consistent, we set the `connection_timeout` value
to None.

Test added for regression.

Author: amitab

lib/mysql/connector/abstracts.py

@@ -62,7 +62,7 @@ def __init__(self, **kwargs):
         self._use_unicode = True
         self._get_warnings = False
         self._raise_on_warnings = False
-        self._connection_timeout = None
+        self._connection_timeout = DEFAULT_CONFIGURATION["connect_timeout"]
         self._buffered = False
         self._unread_result = False
         self._have_next_result = False

lib/mysql/connector/connection.py

@@ -78,7 +78,6 @@ def __init__(self, *args, **kwargs):
         self._use_unicode = True
         self._get_warnings = False
         self._raise_on_warnings = False
-        self._connection_timeout = None
         self._buffered = False
         self._unread_result = False
         self._have_next_result = False

lib/mysql/connector/connection_cext.py

@@ -65,7 +65,6 @@ def __init__(self, **kwargs):
             raise RuntimeError(
                 "MySQL Connector/Python C Extension not available")
         self._cmysql = None
-        self._connection_timeout = 2
         self._columns = []
         self.converter = None
         super(CMySQLConnection, self).__init__(**kwargs)
@@ -144,7 +143,7 @@ def _open_connection(self):
             buffered=self._buffered,
             raw=self._raw,
             charset_name=charset_name,
-            connection_timeout=int(self._connection_timeout or 10),
+            connection_timeout=(self._connection_timeout or 0),
             use_unicode=self._use_unicode,
             auth_plugin=self._auth_plugin)
 

tests/test_bugs.py

@@ -4375,3 +4375,32 @@ def test_pool_exhaustion(self):
                 if not self.mysql_server.check_running():
                     self.mysql_server.start()
                     self.mysql_server.wait_up()
+
+
+class BugOra25558885(tests.MySQLConnectorTests):
+    """BUG#25558885: ERROR 2013 (LOST CONNECTION TO MYSQL SERVER) USING C
+    EXTENSIONS
+    """
+    def setUp(self):
+        pass
+
+    def _long_query(self, config, cursor_class):
+        db_conn = mysql.connector.connect(**config)
+        cur = db_conn.cursor(cursor_class=cursor_class)
+        cur.execute("select sleep(15)")
+        cur.close()
+        db_conn.disconnect()
+
+    def test_cext_cnx(self):
+        config = tests.get_mysql_config()
+        config["use_pure"] = False
+        del config["connection_timeout"]
+        cursor_class = mysql.connector.cursor_cext.CMySQLCursorBufferedRaw
+        self._long_query(config, cursor_class)
+
+    def test_pure_cnx(self):
+        config = tests.get_mysql_config()
+        config["use_pure"] = True
+        del config["connection_timeout"]
+        cursor_class = mysql.connector.cursor.MySQLCursorBufferedRaw
+        self._long_query(config, cursor_class)