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

hgext/patchbomb.py

@@ -533,7 +533,7 b' def _getpatchmsgs(repo, sender, revs, pa'
 def _getoutgoing(repo, dest, revs):
     '''Return the revisions present locally but not in dest'''
     ui = repo.ui
-    paths = urlutil.get_push_paths(repo, ui, [dest])
+    paths = urlutil.get_push_paths(repo, ui, [dest] if dest else None)
     safe_paths = [urlutil.hidepassword(p.rawloc) for p in paths]
     ui.status(_(b'comparing with %s\n') % b','.join(safe_paths))
 

relnotes/next

@@ -18,6 +18,7 b' Mercurial 6.0.'
  * `hg fix --working-dir` now correctly works when in an uncommitted merge state
  * `rhg` (Rust fast-path for `hg`) now supports the full config list syntax
  * `rhg` now parses some corner-cases for revsets correctly
+ * `hg email -o` now works again when not mentioning a revision
  * Lots of Windows fixes
  * Lots of miscellaneous other fixes
 

tests/test-patchbomb.t

@@ -2626,6 +2626,45 b' test outgoing:'
   o  0:8580ff50825a a
   
   $ hg phase --force --secret -r 10
+
+Test without revisions specified
+  $ hg email --date '1980-1-1 0:1' -n -o -t foo
+  comparing with $TESTTMP/t
+  From [test]: test
+  this patch series consists of 1 patches.
+  
+  Cc: 
+  
+  displaying [PATCH] d ...
+  MIME-Version: 1.0
+  Content-Type: text/plain; charset="us-ascii"
+  Content-Transfer-Encoding: 7bit
+  Subject: [PATCH] d
+  X-Mercurial-Node: 2f9fa9b998c5fe3ac2bd9a2b14bfcbeecbc7c268
+  X-Mercurial-Series-Index: 1
+  X-Mercurial-Series-Total: 1
+  Message-Id: <2f9fa9b998c5fe3ac2bd.315532860@test-hostname>
+  X-Mercurial-Series-Id: <2f9fa9b998c5fe3ac2bd.315532860@test-hostname>
+  User-Agent: Mercurial-patchbomb/* (glob)
+  Date: Tue, 01 Jan 1980 00:01:00 +0000
+  From: test
+  To: foo
+  
+  # HG changeset patch
+  # User test
+  # Date 4 0
+  #      Thu Jan 01 00:00:04 1970 +0000
+  # Branch test
+  # Node ID 2f9fa9b998c5fe3ac2bd9a2b14bfcbeecbc7c268
+  # Parent  97d72e5f12c7e84f85064aa72e5a297142c36ed9
+  d
+  
+  diff -r 97d72e5f12c7 -r 2f9fa9b998c5 d
+  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/d	Thu Jan 01 00:00:04 1970 +0000
+  @@ -0,0 +1,1 @@
+  +d
+  
   $ hg email --date '1980-1-1 0:1' -n -t foo -s test -o ../t -r 'rev(10) or rev(6)'
   comparing with ../t
   From [test]: test