memory leak in ConnectionObject_Initialize when mysql_real_connect fails (#350)

We can't set open=0 after we mysql_init or dealloc will not cleanup the memory.

Also if mysql_init returns NULL we are out of memory and shouldn't set open=1, or we could segfault in dealloc if we didn't seg before that.

Author: fried

MySQLdb/_mysql.c

@@ -444,8 +444,12 @@ _mysql_ConnectionObject_Initialize(
         _stringsuck(cipher, value, ssl);
     }
 
-    Py_BEGIN_ALLOW_THREADS ;
     conn = mysql_init(&(self->connection));
+    if (!conn) {
+        PyErr_SetNone(PyExc_MemoryError);
+        return -1;
+    }
+    Py_BEGIN_ALLOW_THREADS ;
     self->open = 1;
     if (connect_timeout) {
         unsigned int timeout = connect_timeout;
@@ -497,7 +501,6 @@ _mysql_ConnectionObject_Initialize(
 
     if (!conn) {
         _mysql_Exception(self);
-        self->open = 0;
         return -1;
     }