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