tests/test-sparse-fsmonitor.t

wrapfunction: use functools.partial if possible

Every `extensions.bind` call inserts a frame in traceback:

   ... in closure
     return func(*(args + a), **kw)

which makes traceback noisy.

The Python stdlib has a `functools.partial` which is backed by C code and
does not pollute traceback. However it does not support instancemethod and
sets `args` attribute which could be problematic for alias handling.

This patch makes `wrapfunction` use `functools.partial` if we are wrapping a
function directly exported by a module (so it's impossible to be a class or
instance method), and special handles `wrapfunction` results so alias
handling code could handle `args` just fine.

As an example, `hg rebase -s . -d . --traceback` got 6 lines removed in my
setup:

   File "hg/mercurial/dispatch.py", line 898, in _dispatch
     cmdpats, cmdoptions)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "hg/hgext/journal.py", line 84, in runcommand
     return orig(lui, repo, cmd, fullargs, *args)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "fb-hgext/hgext3rd/fbamend/hiddenoverride.py", line 119, in runcommand
     result = orig(lui, repo, cmd, fullargs, *args)
   File "hg/mercurial/dispatch.py", line 660, in runcommand
     ret = _runcommand(ui, options, cmd, d)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "hg/hgext/pager.py", line 69, in pagecmd
     return orig(ui, options, cmd, cmdfunc)
   ....

Differential Revision: https://phab.mercurial-scm.org/D632

This test doesn't yet work due to the way fsmonitor is integrated with test runner

  $ exit 80

test sparse interaction with other extensions

  $ hg init myrepo
  $ cd myrepo
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > sparse=
  > strip=
  > EOF

Test fsmonitor integration (if available)
TODO: make fully isolated integration test a'la https://github.com/facebook/watchman/blob/master/tests/integration/WatchmanInstance.py
(this one is using the systemwide watchman instance)

  $ touch .watchmanconfig
  $ echo "ignoredir1/" >> .hgignore
  $ hg commit -Am ignoredir1
  adding .hgignore
  $ echo "ignoredir2/" >> .hgignore
  $ hg commit -m ignoredir2

  $ hg sparse --reset
  $ hg sparse -I ignoredir1 -I ignoredir2 -I dir1

  $ mkdir ignoredir1 ignoredir2 dir1
  $ touch ignoredir1/file ignoredir2/file dir1/file

Run status twice to compensate for a condition in fsmonitor where it will check
ignored files the second time it runs, regardless of previous state (ask @sid0)
  $ hg status --config extensions.fsmonitor=
  ? dir1/file
  $ hg status --config extensions.fsmonitor=
  ? dir1/file

Test that fsmonitor ignore hash check updates when .hgignore changes

  $ hg up -q ".^"
  $ hg status --config extensions.fsmonitor=
  ? dir1/file
  ? ignoredir2/file