- Fixed critical issue whereby the pool "checkout" event handler

may be called against a stale connection without the "connect"
event handler having been called, in the case where the pool
attempted to reconnect after being invalidated and failed; the stale
connection would remain present and would be used on a subsequent
attempt.  This issue has a greater impact in the 1.0 series subsequent
to 1.0.2, as it also delivers a blanked-out ``.info`` dictionary to
the event handler; prior to 1.0.2 the ``.info`` dictionary is still
the previous one.
fixes #3497

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/sqlalchemy/pool.py b/lib/sqlalchemy/pool.py
index b38aefb3d..4dd954fc4 100644
--- a/lib/sqlalchemy/pool.py
+++ b/lib/sqlalchemy/pool.py
@@ -587,7 +587,12 @@ class _ConnectionRecord(object):
         if recycle:
             self.__close()
             self.info.clear()
+
+            # ensure that if self.__connect() fails,
+            # we are not referring to the previous stale connection here
+            self.connection = None
             self.connection = self.__connect()
+
             if self.__pool.dispatch.connect:
                 self.__pool.dispatch.connect(self.connection, self)
         return self.connection