fncache: make debugrebuildfncache not fail on broken fncache
The code reading the fncache changed in 5.0, to complain if the file
is not \n terminated. This makes apparent the fact that the fncache
gets corrupted.
Make it possible to recover, instead of having `hg
debugrebuildfncache` failing by saying `(run hg debugrebuildfncache)`.
The corruption itself is most likely due to hg not using fsync in
general, and so various bad things can happen. Here, the reported
problems happened when running out of disk space. So I suspect that
because the fncache is much bigger than the average commit/pull, when
running out of disk space, the bulk of the pull may succeed, but the
new fncache may get half-written and still renamed into place.
Differential Revision: https://phab.mercurial-scm.org/D6722
# bruterebase.py - brute force rebase testing
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
from mercurial import (
error,
registrar,
revsetlang,
)
from hgext import rebase
try:
xrange
except NameError:
xrange = range
cmdtable = {}
command = registrar.command(cmdtable)
@command(b'debugbruterebase')
def debugbruterebase(ui, repo, source, dest):
"""for every non-empty subset of source, run rebase -r subset -d dest
Print one line summary for each subset. Assume obsstore is enabled.
"""
srevs = list(repo.revs(source))
with repo.wlock(), repo.lock():
repolen = len(repo)
cl = repo.changelog
def getdesc(rev):
result = cl.changelogrevision(rev).description
if rev >= repolen:
result += b"'"
return result
for i in xrange(1, 2 ** len(srevs)):
subset = [rev for j, rev in enumerate(srevs) if i & (1 << j) != 0]
spec = revsetlang.formatspec(b'%ld', subset)
tr = repo.transaction(b'rebase')
tr._report = lambda x: 0 # hide "transaction abort"
ui.pushbuffer()
try:
rebase.rebase(ui, repo, dest=dest, rev=[spec])
except error.Abort as ex:
summary = b'ABORT: %s' % ex
except Exception as ex:
summary = b'CRASH: %s' % ex
else:
# short summary about new nodes
cl = repo.changelog
descs = []
for rev in xrange(repolen, len(repo)):
desc = b'%s:' % getdesc(rev)
for prev in cl.parentrevs(rev):
if prev > -1:
desc += getdesc(prev)
descs.append(desc)
descs.sort()
summary = b' '.join(descs)
ui.popbuffer()
repo.vfs.tryunlink(b'rebasestate')
subsetdesc = b''.join(getdesc(rev) for rev in subset)
ui.write((b'%s: %s\n') % (subsetdesc.rjust(len(srevs)), summary))
tr.abort()