[PATCH stable] dirstate: don't rename branch file if writing it failed

[Pierre-Yves David]

On Fri, Dec 14, 2012 at 04:15:00PM +0200, Idan Kamara wrote:
> # HG changeset patch
> # User Idan Kamara <idankk86 at gmail.com>
> # Date 1355493250 -7200
> # Branch stable
> # Node ID ee7a3e1aff9ca0436f10447b594b6e307e2afad6
> # Parent  ebc0fa067c07808b77f060e285d0c9d8d25c6750
> dirstate: don't rename branch file if writing it failed
> 
> diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
> --- a/mercurial/dirstate.py
> +++ b/mercurial/dirstate.py
> @@ -265,8 +265,9 @@
>          f = self._opener('branch', 'w', atomictemp=True)
>          try:
>              f.write(self._branch + '\n')
> -        finally:
>              f.close()
> +        except:
> +            f.discard()

It looks like you forget to reraise the exception. Otherwise we have a silent
bare except. Those are one of the most annoying things in the
universes.

How did you spotted this? This patch is clearly a welcome fix, but what did
broke without it?