tests/test-issue4074.t

patchbomb: fix traceback on outgoing when not specifying revisions

A user reported that `hg email -n -o` raised with the following traceback:

```
** unknown exception encountered, please report by visiting
** https://mercurial-scm.org/wiki/BugTracker
** Python 3.8.12 (default, Sep 13 2021, 22:12:54) [GCC 7.5.0]
** Mercurial Distributed SCM (version 5.9.1)
** Extensions loaded: patchbomb
Traceback (most recent call last):
  File "/usr/pkg/bin/hg", line 61, in <module>
    dispatch.run()
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 144, in run
    status = dispatch(req)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 250, in dispatch
    status = _rundispatch(req)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 294, in _rundispatch
    ret = _runcatch(req) or 0
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 470, in _runcatch
    return _callcatch(ui, _runcatchfunc)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 480, in _callcatch
    return scmutil.callcatch(ui, func)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/scmutil.py", line 153, in callcatch
    return func()
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 460, in _runcatchfunc
    return _dispatch(req)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 1273, in _dispatch
    return runcommand(
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 918, in runcommand
    ret = _runcommand(ui, options, cmd, d)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 1285, in _runcommand
    return cmdfunc()
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/dispatch.py", line 1271, in <lambda>
    d = lambda: util.checksignature(func)(ui, *args, **strcmdopt)
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/util.py", line 1886, in check
    return func(*args, **kwargs)
  File "/usr/pkg/lib/python3.8/site-packages/hgext/patchbomb.py", line 817, in email
    revs = _getoutgoing(repo, dest, revs)
  File "/usr/pkg/lib/python3.8/site-packages/hgext/patchbomb.py", line 537, in _getoutgoing
    safe_paths = [urlutil.hidepassword(p.rawloc) for p in paths]
  File "/usr/pkg/lib/python3.8/site-packages/hgext/patchbomb.py", line 537, in <listcomp>
    safe_paths = [urlutil.hidepassword(p.rawloc) for p in paths]
  File "/usr/pkg/lib/python3.8/site-packages/mercurial/utils/urlutil.py", line 501, in get_push_paths
    msg %= dest
TypeError: %b requires a bytes-like object, or an object that implements __bytes__, not 'NoneType'
```

This is due to patchbomb passing `[None]` in the `dests` parameter of the
multi-paths outgoing function, we fix this in this change and add a
non-regression test.

Differential Revision: https://phab.mercurial-scm.org/D11456

#require no-pure

A script to generate nasty diff worst-case scenarios:

  $ cat > s.py <<EOF
  > import random
  > for x in range(100000):
  >     print
  >     if random.randint(0, 100) >= 50:
  >         x += 1
  >     print(hex(x))
  > EOF

  $ hg init a
  $ cd a

Check in a big file:

  $ "$PYTHON" ../s.py > a
  $ hg ci -qAm0

Modify it:

  $ "$PYTHON" ../s.py > a

Time a check-in, should never take more than 10 seconds user time:

  $ hg ci --time -m1 --config worker.enabled=no
  time: real .* secs .user [0-9][.].* sys .* (re)