tests/test-bugzilla.t

sshpeer: allow for additional environment passing to ssh exe

We already have the ability to customize the ssh command line arguments, let's
add the ability to customize its environment as well.

Example use-case is ssh.exe from Git on Windows. If `HOME` enviroment variable
is present and has some non-empty value, ssh.exe will try to access that
location for some stuff (for example, it seems for resolving `~` in
`.ssh/config`). Git for Windows seems to sometimess set this variable to the
value of `/home/username` which probably works under Git Bash, but does not
work in a native `cmd.exe` or `powershell`. Whatever the root cause, setting
`HOME` to be an empty string heals things. Therefore, some distributors
might want to set `sshenv.HOME=` in the configuration (seems less intrusive
that forcing everyone to tweak their env).

Test Plan:
- rt

Differential Revision: https://phab.mercurial-scm.org/D1683

mock bugzilla driver for testing template output:

  $ cat <<EOF > bzmock.py
  > from __future__ import absolute_import
  > from mercurial import extensions
  > from mercurial import registrar
  > 
  > configtable = {}
  > configitem = registrar.configitem(configtable)
  > 
  > configitem('bugzilla', 'mocklog',
  >     default=None,
  > )
  > 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.
  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'