- merged the patch from #516 + fixes

- improves the framework for auto-invalidation of connections that have
lost their underlying database - the error catching/invalidate
step is totally moved to the connection pool.
- added better condition checking for do_rollback() and do_commit() including
SQLError excepetion wrapping

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 2943d163e..a26ef76b6 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -338,6 +338,19 @@ class PGDialect(ansisql.ANSIDialect):
         cursor = connection.execute('''SELECT relname FROM pg_class WHERE relkind = 'S' AND relnamespace IN ( SELECT oid FROM pg_namespace WHERE nspname NOT LIKE 'pg_%%' AND nspname != 'information_schema' AND relname = %(seqname)s);''', {'seqname': sequence_name})
         return bool(not not cursor.rowcount)
 
+    def get_disconnect_checker(self):
+        def disconnect_checker(e):
+            if isinstance(e, self.dbapi.OperationalError):
+                return 'closed the connection' in str(e) or 'connection not open' in str(e)
+            elif isinstance(e, self.dbapi.InterfaceError):
+                return 'connection already closed' in str(e)
+            elif isinstance(e, self.dbapi.ProgrammingError):
+                # yes, it really says "losed", not "closed"
+                return "losed the connection unexpectedly" in str(e)
+            else:
+                return False
+        return disconnect_checker
+
     def reflecttable(self, connection, table):
         if self.version == 2:
             ischema_names = pg2_ischema_names