From 47223051d9db2ee0f45c92f8a205efe442aa9e5d Mon Sep 17 00:00:00 2001 From: FUJIWARA Katsunori Date: Thu, 22 Sep 2016 21:51:57 +0900 Subject: [PATCH] vfs: use checkambigatclosing in checkambig=True but atomictemp=False case In Mercurial source tree, opening a file in "a"/"a+" mode like below doesn't specify atomictemp=True for vfs, and this avoids file stat ambiguity check by atomictempfile. - writing changes out in revlog layer uses "a+" mode - truncation in repair.strip() uses "a" mode - truncation in transaction._playback() uses "a" mode If steps below occurs at "the same time in sec", all of mtime, ctime and size are same between (1) and (3). 1. append data to revlog-style file (and close transaction) 2. discard appended data by truncation (strip or rollback) 3. append same size but different data to revlog-style file again Therefore, cache validation doesn't work after (3) as expected. This patch uses checkambigatclosing in checkambig=True but atomictemp=False case, to check (and get rid of) file stat ambiguity at closing. This is a part of ExactCacheValidationPlan. https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan --- mercurial/scmutil.py | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py index 71d6dddacb..d29d702a4d 100644 --- a/mercurial/scmutil.py +++ b/mercurial/scmutil.py @@ -587,6 +587,12 @@ class vfs(abstractvfs): if nlink == 0: self._fixfilemode(f) + if checkambig: + if mode in ('r', 'rb'): + raise error.Abort(_('implementation error: mode %s is not' + ' valid for checkambig=True') % mode) + fp = checkambigatclosing(fp) + if backgroundclose: if not self._backgroundfilecloser: raise error.Abort(_('backgroundclose can only be used when a '