narrow: fix crash when restoring backup in legacy repo
Using --addremove when committing in an old repo (before we started
keeping .hg/narrowspec.dirstate) results in a crash. The test
case modified in this patch would crash like this:
abort: $ENOENT$
The issue is that when the dirstateguard is aborted, it tries to
restore the backup of .hg/narrowspec.dirstate. However, since we were
in an old repo, that file did not get created when the dirstateguard
was created. Note that the dirstateguard is not used unless
--addremove is passed.
This patch fixes the bug by making restorewcbackup() not fail if the
backup doesn't exist. I also made clearwcbackup() safe, just in case.
Differential Revision: https://phab.mercurial-scm.org/D5634
#!/usr/bin/env python
from __future__ import absolute_import
__doc__ = """Same as `echo a >> b`, but ensures a changed mtime of b.
Without this svn will not detect workspace changes."""
import os
import stat
import sys
if sys.version_info[0] >= 3:
text = os.fsencode(sys.argv[1])
fname = os.fsencode(sys.argv[2])
else:
text = sys.argv[1]
fname = sys.argv[2]
f = open(fname, "ab")
try:
before = os.fstat(f.fileno())[stat.ST_MTIME]
f.write(text)
f.write(b"\n")
finally:
f.close()
inc = 1
now = os.stat(fname)[stat.ST_MTIME]
while now == before:
t = now + inc
inc += 1
os.utime(fname, (t, t))
now = os.stat(fname)[stat.ST_MTIME]