bundle2-localpeer: properly propagate the server output on error (issue4594)

In case of errors, output parts salvaged from the reply bundle need to be
processed for outputting their content. This concludes our quest for fixing
issue4594.

mercurial/localrepo.py

@@ -136,6 +136,21 b' class localpeer(peer.peerrepository):'
                     ret = bundle2.getunbundler(self.ui, stream)
                 return ret
             except Exception, exc:
+                # If the exception contains output salvaged from a bundle2
+                # reply, we need to make sure it is printed before continuing
+                # to fail. So we build a bundle2 with such output and consume
+                # it directly.
+                #
+                # This is not very elegant but allows a "simple" solution for
+                # issue4594
+                output = getattr(exc, '_bundle2salvagedoutput', ())
+                if output:
+                    bundler = bundle2.bundle20(self._repo.ui)
+                    for out in output:
+                        bundler.addpart(out)
+                    stream = util.chunkbuffer(bundler.getchunks())
+                    b = bundle2.getunbundler(self.ui, stream)
+                    bundle2.processbundle(self._repo, b)
                 raise
         except error.PushRaced, exc:
             raise error.ResponseError(_('push failed:'), str(exc))

tests/test-bundle2-exchange.t

@@ -561,6 +561,10 b' Doing the actual push: hook abort'
   pre-close-tip:e7ec4e813ba6 draft 
   transaction abort!
   rollback completed
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 1 changesets with 1 changes to 1 files
   abort: pretxnclose.failpush hook exited with status 1
   [255]