Fri, 15 Nov 2019 14:41:00 -0800 commit: rewrite check for `hg ci <path>` being a directory
Martin von Zweigbergk <martinvonz@google.com> [Fri, 15 Nov 2019 14:41:00 -0800] rev 43711
commit: rewrite check for `hg ci <path>` being a directory The matcher API is complicated by match.bad, match.explicitdir, and match.traversedir. We already have very few users of match.explicitdir. By rewriting this check we get close to being able to remove match.explicitdir. This may make the check slower, but I think that will be very marginal. Disclosure: I actually wrote this patch to solve a bug we've seen with an internal extension. The internal extension overrides the dirstate walk to only walk the files that our FUSE tells us are modified. That led to "vdirs" not getting populated as this code expected. I have wanted to get rid of match.explicitdir for a very long time, though. Differential Revision: https://phab.mercurial-scm.org/D7437
Tue, 19 Nov 2019 11:59:43 +0100 py3: use pycompat.bytestr() instead of pycompat.sysstr() stable
Manuel Jacob <me@manueljacob.de> [Tue, 19 Nov 2019 11:59:43 +0100] rev 43710
py3: use pycompat.bytestr() instead of pycompat.sysstr() pycompat.sysstr() doesn’t work because it doesn’t accept arguments of type `type` and returns a unicode object on Python3, while the format string wants a bytes-like object.
Mon, 18 Nov 2019 20:10:38 -0800 lock: fix race in lock-breaking code
Valentin Gatien-Baron <valentin.gatienbaron@gmail.com> [Mon, 18 Nov 2019 20:10:38 -0800] rev 43709
lock: fix race in lock-breaking code With low frequency, I see hg pulls fail with output like: abort: no such file or directory: .hg/store/lock I think what happens is, in lock.py, in: def _testlock(self, locker): if not self._lockshouldbebroken(locker): return locker # if locker dead, break lock. must do this with another lock # held, or can race and break valid lock. try: with lock(self.vfs, self.f + b'.break', timeout=0): self.vfs.unlink(self.f) except error.LockError: return locker if a lock is breakable on disk, and two hg processes concurrently get to the "if locker dead" comment, a possible interleaving is: process1 finishes executing the function and then process2 finishes executing the function. If that happens, process2 will either get ENOENT in self.vfs.unlink (resulting in the spurious failure above), or break a valid lock and potentially cause repository corruption. The fix is simple enough: make sure the lock is breakable _inside_ the critical section, because only then can we know that no other process can invalidate our knowledge on the lock on disk. I don't think there are tests for this. I've tested this manually with: diff --git a/mercurial/lock.py b/mercurial/lock.py --- a/mercurial/lock.py +++ b/mercurial/lock.py @@ -351,6 +351,8 @@ class lock(object): if not self._lockshouldbebroken(locker): return locker + import random + time.sleep(1. + random.random()) # if locker dead, break lock. must do this with another lock # held, or can race and break valid lock. try: @@ -358,6 +360,7 @@ class lock(object): self.vfs.unlink(self.f) except error.LockError: return locker + time.sleep(1) def testlock(self): """return id of locker if lock is valid, else None. and I see this change of behavior before/after this commit: $ $hg init repo $ cd repo $ ln -s $HOSTNAME/effffffc:987654321 .hg/wlock $ touch a $ $hg commit -Am_ & $hg commit -Am _; wait -abort: No such file or directory: '/tmp/repo/.hg/wlock' adding a +warning: ignoring unknown working parent 679a8959a8ca! +nothing changed Differential Revision: https://phab.mercurial-scm.org/D7199
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