view tests/test-devel-warnings.t @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

  $ cat << EOF > buggylocking.py
  > """A small extension that tests our developer warnings
  > """
  > 
  > from mercurial import error, registrar, repair, util
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > @command(b'buggylocking', [], '')
  > def buggylocking(ui, repo):
  >     lo = repo.lock()
  >     wl = repo.wlock()
  >     wl.release()
  >     lo.release()
  > 
  > @command(b'buggytransaction', [], '')
  > def buggylocking(ui, repo):
  >     tr = repo.transaction(b'buggy')
  >     # make sure we rollback the transaction as we don't want to rely on the__del__
  >     tr.release()
  > 
  > @command(b'properlocking', [], '')
  > def properlocking(ui, repo):
  >     """check that reentrance is fine"""
  >     wl = repo.wlock()
  >     lo = repo.lock()
  >     tr = repo.transaction(b'proper')
  >     tr2 = repo.transaction(b'proper')
  >     lo2 = repo.lock()
  >     wl2 = repo.wlock()
  >     wl2.release()
  >     lo2.release()
  >     tr2.close()
  >     tr.close()
  >     lo.release()
  >     wl.release()
  > 
  > @command(b'nowaitlocking', [], '')
  > def nowaitlocking(ui, repo):
  >     lo = repo.lock()
  >     wl = repo.wlock(wait=False)
  >     wl.release()
  >     lo.release()
  > 
  > @command(b'no-wlock-write', [], '')
  > def nowlockwrite(ui, repo):
  >     with repo.vfs(b'branch', b'a'):
  >         pass
  > 
  > @command(b'no-lock-write', [], '')
  > def nolockwrite(ui, repo):
  >     with repo.svfs(b'fncache', b'a'):
  >         pass
  > 
  > @command(b'stripintr', [], '')
  > def stripintr(ui, repo):
  >     lo = repo.lock()
  >     tr = repo.transaction(b'foobar')
  >     try:
  >         repair.strip(repo.ui, repo, [repo[b'.'].node()])
  >     finally:
  >         lo.release()
  > @command(b'oldanddeprecated', [], '')
  > def oldanddeprecated(ui, repo):
  >     """test deprecation warning API"""
  >     def foobar(ui):
  >         ui.deprecwarn(b'foorbar is deprecated, go shopping', b'42.1337')
  >     foobar(ui)
  > @command(b'nouiwarning', [], '')
  > def nouiwarning(ui, repo):
  >     util.nouideprecwarn(b'this is a test', b'13.37')
  > @command(b'programmingerror', [], '')
  > def programmingerror(ui, repo):
  >     raise error.ProgrammingError(b'something went wrong', hint=b'try again')
  > EOF

  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > buggylocking=$TESTTMP/buggylocking.py
  > mock=$TESTDIR/mockblackbox.py
  > blackbox=
  > [devel]
  > all-warnings=1
  > [blackbox]
  > track = command, commandexception, commandfinish, develwarn
  > EOF

  $ hg init lock-checker
  $ cd lock-checker
  $ hg buggylocking
  devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:* (buggylocking) (glob)
  $ cat << EOF >> $HGRCPATH
  > [devel]
  > all=0
  > check-locks=1
  > EOF
  $ hg buggylocking
  devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:* (buggylocking) (glob)
#if no-chg
  $ hg buggylocking --traceback
  devel-warn: "wlock" acquired after "lock" at:
   */hg:* in <module> (glob) (?)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in buggylocking (glob)
#else
  $ hg buggylocking --traceback
  devel-warn: "wlock" acquired after "lock" at:
   */hg:* in <module> (glob) (?)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   */mercurial/commands.py:* in serve (glob)
   */mercurial/server.py:* in runservice (glob)
   */mercurial/commandserver.py:* in run (glob)
   */mercurial/commandserver.py:* in _mainloop (glob)
   */mercurial/commandserver.py:* in _acceptnewconnection (glob)
   */mercurial/commandserver.py:* in _runworker (glob)
   */mercurial/commandserver.py:* in _serverequest (glob)
   */mercurial/commandserver.py:* in serve (glob)
   */mercurial/commandserver.py:* in serveone (glob)
   */mercurial/chgserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in _dispatchcommand (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in buggylocking (glob)
#endif
  $ hg properlocking
  $ hg nowaitlocking

Writing without lock

  $ hg no-wlock-write
  devel-warn: write with no wlock: "branch" at: $TESTTMP/buggylocking.py:* (nowlockwrite) (glob)

  $ hg no-lock-write
  devel-warn: write with no lock: "fncache" at: $TESTTMP/buggylocking.py:* (nolockwrite) (glob)

Stripping from a transaction

  $ echo a > a
  $ hg add a
  $ hg commit -m a
  $ hg stripintr 2>&1 | egrep -v '^(\*\*|  )'
  Traceback (most recent call last):
  *ProgrammingError: cannot strip from inside a transaction (glob)

  $ hg oldanddeprecated
  devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)

#if no-chg
  $ hg oldanddeprecated --traceback
  devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at:
   */hg:* in <module> (glob) (?)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
#else
  $ hg oldanddeprecated --traceback
  devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at:
   */hg:* in <module> (glob)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   */mercurial/commands.py:* in serve (glob)
   */mercurial/server.py:* in runservice (glob)
   */mercurial/commandserver.py:* in run (glob)
   */mercurial/commandserver.py:* in _mainloop (glob)
   */mercurial/commandserver.py:* in _acceptnewconnection (glob)
   */mercurial/commandserver.py:* in _runworker (glob)
   */mercurial/commandserver.py:* in _serverequest (glob)
   */mercurial/commandserver.py:* in serve (glob)
   */mercurial/commandserver.py:* in serveone (glob)
   */mercurial/chgserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in _dispatchcommand (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
#endif

#if no-chg
  $ hg blackbox -l 7
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at:
   */hg:* in <module> (glob) (?)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> blackbox -l 7
#else
  $ hg blackbox -l 7
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
  (compatibility will be dropped after Mercurial-42.1337, update your code.) at:
   */hg:* in <module> (glob)
   */mercurial/dispatch.py:* in run (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   */mercurial/commands.py:* in serve (glob)
   */mercurial/server.py:* in runservice (glob)
   */mercurial/commandserver.py:* in run (glob)
   */mercurial/commandserver.py:* in _mainloop (glob)
   */mercurial/commandserver.py:* in _acceptnewconnection (glob)
   */mercurial/commandserver.py:* in _runworker (glob)
   */mercurial/commandserver.py:* in _serverequest (glob)
   */mercurial/commandserver.py:* in serve (glob)
   */mercurial/commandserver.py:* in serveone (glob)
   */mercurial/chgserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in runcommand (glob)
   */mercurial/commandserver.py:* in _dispatchcommand (glob)
   */mercurial/dispatch.py:* in dispatch (glob)
   */mercurial/dispatch.py:* in _rundispatch (glob)
   */mercurial/dispatch.py:* in _runcatch (glob)
   */mercurial/dispatch.py:* in _callcatch (glob)
   */mercurial/scmutil.py:* in callcatch (glob)
   */mercurial/dispatch.py:* in _runcatchfunc (glob)
   */mercurial/dispatch.py:* in _dispatch (glob)
   */mercurial/dispatch.py:* in runcommand (glob)
   */mercurial/dispatch.py:* in _runcommand (glob)
   */mercurial/dispatch.py:* in <lambda> (glob)
   */mercurial/util.py:* in check (glob)
   $TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> blackbox -l 7
#endif

Test programming error failure:

  $ hg buggytransaction 2>&1 | egrep -v '^  '
  ** Unknown exception encountered with possibly-broken third-party extension "buggylocking" (version N/A)
  ** which supports versions unknown of Mercurial.
  ** Please disable "buggylocking" and try your action again.
  ** If that fixes the bug please report it to the extension author.
  ** Python * (glob)
  ** Mercurial Distributed SCM (*) (glob)
  ** Extensions loaded: * (glob)
  ** ProgrammingError: transaction requires locking
  Traceback (most recent call last):
  *ProgrammingError: transaction requires locking (glob)

  $ hg programmingerror 2>&1 | egrep -v '^  '
  ** Unknown exception encountered with possibly-broken third-party extension "buggylocking" (version N/A)
  ** which supports versions unknown of Mercurial.
  ** Please disable "buggylocking" and try your action again.
  ** If that fixes the bug please report it to the extension author.
  ** Python * (glob)
  ** Mercurial Distributed SCM (*) (glob)
  ** Extensions loaded: * (glob)
  ** ProgrammingError: something went wrong
  ** (try again)
  Traceback (most recent call last):
  *ProgrammingError: something went wrong (glob)

Old style deprecation warning

  $ hg nouiwarning
  $TESTTMP/buggylocking.py:*: DeprecationWarning: this is a test (glob)
  (compatibility will be dropped after Mercurial-13.37, update your code.)
    util.nouideprecwarn(b'this is a test', b'13.37')

(disabled outside of test run)

  $ HGEMITWARNINGS= hg nouiwarning

Test warning on config option access and registration

  $ cat << EOF > ${TESTTMP}/buggyconfig.py
  > """A small extension that tests our developer warnings for config"""
  > 
  > from mercurial import configitems, registrar
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > configtable = {}
  > configitem = registrar.configitem(configtable)
  > 
  > configitem(b'test', b'some', default=b'foo')
  > configitem(b'test', b'dynamic', default=configitems.dynamicdefault)
  > configitem(b'test', b'callable', default=list)
  > # overwrite a core config
  > configitem(b'ui', b'quiet', default=False)
  > configitem(b'ui', b'interactive', default=None)
  > 
  > @command(b'buggyconfig')
  > def cmdbuggyconfig(ui, repo):
  >     repo.ui.config(b'ui', b'quiet', True)
  >     repo.ui.config(b'ui', b'interactive', False)
  >     repo.ui.config(b'test', b'some', b'bar')
  >     repo.ui.config(b'test', b'some', b'foo')
  >     repo.ui.config(b'test', b'dynamic', b'some-required-default')
  >     repo.ui.config(b'test', b'dynamic')
  >     repo.ui.config(b'test', b'callable', [])
  >     repo.ui.config(b'test', b'callable', b'foo')
  >     repo.ui.config(b'test', b'unregistered')
  >     repo.ui.config(b'unregistered', b'unregistered')
  > EOF

  $ hg --config "extensions.buggyconfig=${TESTTMP}/buggyconfig.py" buggyconfig
  devel-warn: extension 'buggyconfig' overwrite config item 'ui.interactive' at: */mercurial/extensions.py:* (_loadextra) (glob)
  devel-warn: extension 'buggyconfig' overwrite config item 'ui.quiet' at: */mercurial/extensions.py:* (_loadextra) (glob)
  devel-warn: specifying a mismatched default value for a registered config item: 'ui.quiet' 'True' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: specifying a mismatched default value for a registered config item: 'ui.interactive' 'False' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: specifying a mismatched default value for a registered config item: 'test.some' 'bar' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: config item requires an explicit default value: 'test.dynamic' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: specifying a mismatched default value for a registered config item: 'test.callable' 'foo' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: accessing unregistered config item: 'test.unregistered' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
  devel-warn: accessing unregistered config item: 'unregistered.unregistered' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)

  $ cd ..