id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
17624	Transaction committed on user abort	George Lund	nobody	"If the user aborts execution of some code (e.g. with Control+C), any ongoing transaction is committed, rather than rolled back. This is in Python 2.5, I suspect later versions could be different.

{{{
from __future__ import with_statement
from django.db import transaction
with transaction.commit_on_success():
 for x in xx:
  # long loop
}}}

If an ""normal"" exception is raised during the long loop, the transaction aborts correctly.

However, if the user presses Control+C (very possible during a management command), the half-finished transaction is committed.

The reason is that the Transaction's  [https://code.djangoproject.com/browser/django/trunk/django/db/transaction.py#L202 __exit__ method] only passes on exc_value, but not exc_type.

At least in Python 2.5, exc_type can be set, whilst exc_value is still None.

{{{
(Pdb) exc_type
<type 'exceptions.KeyboardInterrupt'>
(Pdb) exc_value
(Pdb) exc_value is None
True
}}}

This is really confusing, and I'd certainly hope it got fixed in a later version of Python.

From a brief look at the code it looks like rather than pass on exc_value to the `exiting` function, we could just pass on a Boolean success flag, based on whether any of the three `__exit__` parameters were set. I'll try and work up a patch today.









 "	Bug	closed	Database layer (models, ORM)	1.3	Normal	duplicate			Unreviewed	1	0	0	0	0	0