view tests/test-lock-badness.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

#require unix-permissions no-root no-windows

Prepare

  $ hg init a
  $ echo a > a/a
  $ hg -R a ci -A -m a
  adding a

  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Test that raising an exception in the release function doesn't cause the lock to choke

  $ cat > testlock.py << EOF
  > from mercurial import error, registrar
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > def acquiretestlock(repo, releaseexc):
  >     def unlock():
  >         if releaseexc:
  >             raise error.Abort(b'expected release exception')
  >     l = repo._lock(repo.vfs, b'testlock', False, unlock, None, b'test lock')
  >     return l
  > 
  > @command(b'testlockexc')
  > def testlockexc(ui, repo):
  >     testlock = acquiretestlock(repo, True)
  >     try:
  >         testlock.release()
  >     finally:
  >         try:
  >             testlock = acquiretestlock(repo, False)
  >         except error.LockHeld:
  >             raise error.Abort(b'lockfile on disk even after releasing!')
  >         testlock.release()
  > EOF
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > testlock=$TESTTMP/testlock.py
  > EOF

  $ hg -R b testlockexc
  abort: expected release exception
  [255]

One process waiting for another

  $ cat > hooks.py << EOF
  > import time
  > def sleepone(**x): time.sleep(1)
  > def sleephalf(**x): time.sleep(0.5)
  > EOF
  $ echo b > b/b
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up -q --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  $ cat preup-stderr
  waiting for lock on working directory of b held by process '*' on host '*' (glob)
  got lock after * seconds (glob)
  $ cat stdout
  adding b

On processs waiting on another, warning after a long time.

  $ echo b > b/c
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up -q --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=250 \
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  $ cat preup-stderr
  $ cat stdout
  adding c

On processs waiting on another, warning disabled.

  $ echo b > b/d
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up -q --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=-1 \
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  $ cat preup-stderr
  $ cat stdout
  adding d

check we still print debug output

On processs waiting on another, warning after a long time (debug output on)

  $ echo b > b/e
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=250 --debug\
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  calling hook pre-update: hghook_pre-update.sleephalf
  waiting for lock on working directory of b held by process '*' on host '*' (glob)
  got lock after * seconds (glob)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat preup-stderr
  $ cat stdout
  adding e

On processs waiting on another, warning disabled, (debug output on)

  $ echo b > b/f
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=-1 --debug\
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  calling hook pre-update: hghook_pre-update.sleephalf
  waiting for lock on working directory of b held by process '*' on host '*' (glob)
  got lock after * seconds (glob)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat preup-stderr
  $ cat stdout
  adding f

Pushing to a local read-only repo that can't be locked

  $ chmod 100 a/.hg/store

  $ hg -R b push a
  pushing to a
  searching for changes
  abort: could not lock repository a: Permission denied
  [255]

  $ chmod 700 a/.hg/store