tests/test-bugzilla.t

ui: add special-purpose atexit functionality

In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:

* Handlers run after application code has finished.

* Because of this, the code that runs handlers swallows exceptions
  (since there's no possible stacktrace to associate errors with).
  If we're lucky, we'll get something spat out to stderr (if stderr
  still works), which of course isn't any use in a big deployment
  where it's important that exceptions get logged and aggregated.

* Mercurial's current atexit handlers make unfortunate assumptions
  about process state (specifically stdio) that, coupled with the
  above problems, make it impossible to deal with certain categories
  of error (try "hg status > /dev/full" on a Linux box).

* In Python 3, the atexit implementation is completely hidden, so
  we can't hijack the platform's atexit code to run handlers at a
  time of our choosing.

As a result, here's a perfectly cromulent atexit-like implementation
over which we have control.  This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).

mock bugzilla driver for testing template output:

  $ cat <<EOF > bzmock.py
  > from __future__ import absolute_import
  > from mercurial import extensions
  > 
  > def extsetup(ui):
  >     bugzilla = extensions.find('bugzilla')
  >     class bzmock(bugzilla.bzaccess):
  >         def __init__(self, ui):
  >             super(bzmock, self).__init__(ui)
  >             self._logfile = ui.config('bugzilla', 'mocklog')
  >         def updatebug(self, bugid, newstate, text, committer):
  >             with open(self._logfile, 'a') as f:
  >                 f.write('update bugid=%r, newstate=%r, committer=%r\n'
  >                         % (bugid, newstate, committer))
  >                 f.write('----\n' + text + '\n----\n')
  >         def notify(self, bugs, committer):
  >             with open(self._logfile, 'a') as f:
  >                 f.write('notify bugs=%r, committer=%r\n'
  >                         % (bugs, committer))
  >     bugzilla.bugzilla._versions['mock'] = bzmock
  > EOF

set up mock repository:

  $ hg init mockremote
  $ cat <<EOF > mockremote/.hg/hgrc
  > [extensions]
  > bugzilla =
  > bzmock = $TESTTMP/bzmock.py
  > 
  > [bugzilla]
  > version = mock
  > mocklog = $TESTTMP/bzmock.log
  > 
  > [hooks]
  > incoming.bugzilla = python:hgext.bugzilla.hook
  > 
  > [web]
  > baseurl=http://example.org/hg
  > 
  > %include $TESTTMP/bzstyle.hgrc
  > EOF

  $ hg clone -q mockremote mocklocal

push with default template:

  $ echo '[bugzilla]' > bzstyle.hgrc
  $ echo foo > mocklocal/foo
  $ hg ci -R mocklocal -Aqm 'Fixes bug 123'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=123, newstate={}, committer='test'
  ----
  changeset 7875a8342c6f in repo $TESTTMP/mockremote refers to bug 123. (glob)
  details:
  	Fixes bug 123
  ----
  notify bugs={123: {}}, committer='test'

push with style:

  $ cat <<EOF > bzstyle.map
  > changeset = "{node|short} refers to bug {bug}."
  > EOF
  $ echo "style = $TESTTMP/bzstyle.map" >> bzstyle.hgrc
  $ echo foo >> mocklocal/foo
  $ hg ci -R mocklocal -qm 'Fixes bug 456'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=456, newstate={}, committer='test'
  ----
  2808b172464b refers to bug 456.
  ----
  notify bugs={456: {}}, committer='test'

push with template (overrides style):

  $ cat <<EOF >> bzstyle.hgrc
  > template = Changeset {node|short} in {root|basename}.
  >            {hgweb}/rev/{node|short}\n
  >            {desc}
  > EOF
  $ echo foo >> mocklocal/foo
  $ hg ci -R mocklocal -qm 'Fixes bug 789'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=789, newstate={}, committer='test'
  ----
  Changeset a770f3e409f2 in mockremote.
  http://example.org/hg/rev/a770f3e409f2
  
  Fixes bug 789
  ----
  notify bugs={789: {}}, committer='test'