view contrib/plan9/9mail @ 25365:4cc3fb23881d

hg: explicitly check that peer lookup object has instance() if call failed

If a "thing" is callable but raises TypeError for some reason, a callable
object would be returned. Thereafter, unfriendly traceback would be displayed:

  Traceback (most recent call last):
    ...
    File "mercurial/hg.pyc", line 119, in _peerorrepo
      obj = _peerlookup(path).instance(ui, path, create)
  AttributeError: 'function' object has no attribute 'instance'

Instead, we should show the reason why "thing(path)" didn't work:

  Traceback (most recent call last):
    ...
    File "hggit/__init__.py", line 89, in _local
      p = urlcls(path).localpath()
  TypeError: 'NoneType' object is not callable

If a "thing" is not callable, it must be a module or an object that implements
instance(). If that module didn't have instance(), the error message would be
"<unloaded module 'foo'> object is not callable". It doesn't make perfect sense,
but it isn't so bad as it can blame which module went wrong.

#!/bin/rc
# 9mail - Mercurial email wrapper for upas/marshal

fn usage {
	echo >[1=2] usage: mercurial/9mail -f from to [cc]
	exit usage
}

from=()
cc=()
to=()

switch($1){
case -f
	from=$2
case *
	usage
}

to=($3)
if(~ $#* 4)
	cc=(-C $4)

upasname=$from
upas/marshal $cc $to