tests/test-rebase-brute-force.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

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > drawdag=$TESTDIR/drawdag.py
  > bruterebase=$TESTDIR/bruterebase.py
  > [experimental]
  > evolution=createmarkers,allowunstable
  > EOF
  $ init() {
  >   N=`expr ${N:-0} + 1`
  >   cd $TESTTMP && hg init repo$N && cd repo$N
  >   hg debugdrawdag
  > }

Source looks like "N"

  $ init <<'EOS'
  > C D
  > |\|
  > A B Z
  > EOS

  $ hg debugbruterebase 'all()-Z' Z
     A: A':Z
     B: B':Z
    AB: A':Z B':Z
     C: ABORT: cannot rebase 3:a35c07e8a2a4 without moving at least one of its parents
    AC: A':Z C':A'B
    BC: B':Z C':B'A
   ABC: A':Z B':Z C':A'B'
     D: D':Z
    AD: A':Z D':Z
    BD: B':Z D':B'
   ABD: A':Z B':Z D':B'
    CD: ABORT: cannot rebase 3:a35c07e8a2a4 without moving at least one of its parents
   ACD: A':Z C':A'B D':Z
   BCD: B':Z C':B'A D':B'
  ABCD: A':Z B':Z C':A'B' D':B'

Moving backwards

  $ init <<'EOS'
  > C
  > |\
  > A B
  > |
  > Z
  > EOS
  $ hg debugbruterebase 'all()-Z' Z
    B: B':Z
    A: 
   BA: B':Z
    C: ABORT: cannot rebase 3:b8d7149b562b without moving at least one of its parents
   BC: B':Z C':B'A
   AC: 
  BAC: B':Z C':B'A