tests/test-hgweb-bundle.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

#require serve

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

  $ echo 1 > foo
  $ hg commit -A -m 'first'
  adding foo
  $ echo 2 > bar
  $ hg commit -A -m 'second'
  adding bar

Produce a bundle to use

  $ hg strip -r 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/server/.hg/strip-backup/ed602e697e0f-cc9fff6a-backup.hg (glob)

Serve from a bundle file

  $ hg serve -R .hg/strip-backup/ed602e697e0f-cc9fff6a-backup.hg -d -p $HGPORT --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS

Ensure we're serving from the bundle

  $ (get-with-headers.py localhost:$HGPORT 'file/tip/?style=raw')
  200 Script output follows
  
  
  -rw-r--r-- 2 bar
  -rw-r--r-- 2 foo