bundle1: fix bundle1-denied reporting for push over ssh

Changeset b288fb2724bf introduced a config option to have the server deny push
using bundle1. The original protocol has not really be design to allow such kind
of error reporting so some hack was used. It turned the hack only works on HTTP
and that ssh wire peer hangs forever when the same hack is used. After further
digging, there is no way to report the error in a unified way. Using 'ooberror'
freeze ssh and raising 'Abort' makes HTTP return a HTTP500 without further
details. So with sadness we implement a version that dispatch according to the
protocol used.

We also add a test for pushing over ssh to make sure we won't regress in the
future. That test show that the hint is missing, this is another bug fixed in
the next changeset.

mercurial/wireproto.py

@@ -33,9 +33,10 b' from . import ('
 urlerr = util.urlerr
 urlreq = util.urlreq
 
-bundle2required = _(
-    'incompatible Mercurial client; bundle2 required\n'
-    '(see https://www.mercurial-scm.org/wiki/IncompatibleClient)\n')
+bundle2requiredmain = _('incompatible Mercurial client; bundle2 required')
+bundle2requiredhint = _('see https://www.mercurial-scm.org/wiki/'
+                        'IncompatibleClient')
+bundle2required = '%s\n(%s)\n' % (bundle2requiredmain, bundle2requiredhint)
 
 class abstractserverproto(object):
     """abstract class that summarizes the protocol API
@@ -948,7 +949,14 b' def unbundle(repo, proto, heads):'
             gen = exchange.readbundle(repo.ui, fp, None)
             if (isinstance(gen, changegroupmod.cg1unpacker)
                 and not bundle1allowed(repo, 'push')):
-                return ooberror(bundle2required)
+                if proto.name == 'http':
+                    # need to special case http because stderr do not get to
+                    # the http client on failed push so we need to abuse some
+                    # other error type to make sure the message get to the
+                    # user.
+                    return ooberror(bundle2required)
+                raise error.Abort(bundle2requiredmain,
+                                  hint=bundle2requiredhint)
 
             r = exchange.unbundle(repo, gen, their_heads, 'serve',
                                   proto._client())

tests/test-bundle2-exchange.t

@@ -1107,6 +1107,14 b' Verify bundle1 pushes can be disabled'
   (see https://www.mercurial-scm.org/wiki/IncompatibleClient)
   [255]
 
+(also check with ssh)
+
+  $ hg --config devel.legacy.exchange=bundle1 push ssh://user@dummy/bundle2onlyserver
+  pushing to ssh://user@dummy/bundle2onlyserver
+  searching for changes
+  remote: abort: incompatible Mercurial client; bundle2 required
+  [1]
+
   $ hg push
   pushing to http://localhost:$HGPORT/
   searching for changes