| Submitter | Matt Harbison |
|---|---|
| Date | Feb. 6, 2015, 3:19 a.m. |
| Message ID | <05678c22e04da407ab61.1423192754@Envy> |
| Download | mbox | patch |
| Permalink | /patch/7701/ |
| State | Accepted |
| Commit | 7956d17431bce17300c36c74021dbbb1edf299a3 |
| Headers | show |
Comments
On 2015-02-06 04:19, Matt Harbison wrote: > # HG changeset patch > # User Matt Harbison <matt_harbison@yahoo.com> > # Date 1422725984 18000 > # Sat Jan 31 12:39:44 2015 -0500 > # Node ID 05678c22e04da407ab610765248636a125e1348a > # Parent a9b61dbdb827165a9fd9d44dd42b892dbd9fa07c > windows: seek to the end of posixfile when opening in append mode > > The position is implementation defined when opening in append mode, and it seems > like Linux sets it to EOF while Windows keeps it at zero. This has caused > problems in the past when a file is opened and tell() is immediately called, > such as 48c232873a54 and 6bf93440a717. .. > Since the only caller of osutil.posixfile is this windows module, this seems > like a better place to fix the issue than in osutil.c and pure.osutil. Yep. Probably not worth the extra work. And it could be moved to osutil.c as a followup later if really needed. > diff --git a/mercurial/windows.py b/mercurial/windows.py > --- a/mercurial/windows.py > +++ b/mercurial/windows.py > @@ -26,11 +26,19 @@ > unlink = win32.unlink > > umask = 0022 > +_SEEK_END = 2 # os.SEEK_END was introduced in Python 2.5 > > # wrap osutil.posixfile to provide friendlier exceptions > def posixfile(name, mode='r', buffering=-1): > try: > - return osutil.posixfile(name, mode, buffering) > + fp = osutil.posixfile(name, mode, buffering) > + > + # The position when opening in append mode is implementation defined, so > + # make it consistent with other platforms, which position at EOF. > + if 'a' in mode: > + fp.seek(0, _SEEK_END) > + > + return fp > except WindowsError, err: > raise IOError(err.errno, '%s: %s' % (name, err.strerror)) > posixfile.__doc__ = osutil.posixfile.__doc__ I would probably have placed the seek call outside of the try-block, but this looks good enough to me either way.
Patch
diff --git a/mercurial/windows.py b/mercurial/windows.py --- a/mercurial/windows.py +++ b/mercurial/windows.py @@ -26,11 +26,19 @@ unlink = win32.unlink umask = 0022 +_SEEK_END = 2 # os.SEEK_END was introduced in Python 2.5 # wrap osutil.posixfile to provide friendlier exceptions def posixfile(name, mode='r', buffering=-1): try: - return osutil.posixfile(name, mode, buffering) + fp = osutil.posixfile(name, mode, buffering) + + # The position when opening in append mode is implementation defined, so + # make it consistent with other platforms, which position at EOF. + if 'a' in mode: + fp.seek(0, _SEEK_END) + + return fp except WindowsError, err: raise IOError(err.errno, '%s: %s' % (name, err.strerror)) posixfile.__doc__ = osutil.posixfile.__doc__