bundle2: gracefully handle hook abort

We make sure any exceptions raised during the whole span of handling bundle2
processing are decorated. This let us catch exceptions raised by hooks prior to
transaction commit.

mercurial/exchange.py

@@ -738,16 +738,20 b' def unbundle(repo, cg, heads, source, ur'
         check_heads(repo, heads, 'uploading changes')
         # push can proceed
         if util.safehasattr(cg, 'params'):
-            tr = repo.transaction('unbundle')
-            tr.hookargs['bundle2-exp'] = '1'
-            r = bundle2.processbundle(repo, cg, lambda: tr).reply
-            cl = repo.unfiltered().changelog
-            p = cl.writepending() and repo.root or ""
-            repo.hook('b2x-pretransactionclose', throw=True, source=source,
-                      url=url, pending=p, **tr.hookargs)
-            tr.close()
-            repo.hook('b2x-transactionclose', source=source, url=url,
-                      **tr.hookargs)
+            try:
+                tr = repo.transaction('unbundle')
+                tr.hookargs['bundle2-exp'] = '1'
+                r = bundle2.processbundle(repo, cg, lambda: tr).reply
+                cl = repo.unfiltered().changelog
+                p = cl.writepending() and repo.root or ""
+                repo.hook('b2x-pretransactionclose', throw=True, source=source,
+                          url=url, pending=p, **tr.hookargs)
+                tr.close()
+                repo.hook('b2x-transactionclose', source=source, url=url,
+                          **tr.hookargs)
+            except Exception, exc:
+                exc.duringunbundle2 = True
+                raise
         else:
             r = changegroup.addchangegroup(repo, cg, source, url)
     finally:

tests/test-bundle2.t

@@ -1043,3 +1043,40 b' Doing the actual push: race'
   abort: push failed:
   'repository changed while pushing - please try again'
   [255]
+
+Doing the actual push: hook abort
+
+  $ cat << EOF >> $HGRCPATH
+  > [failpush]
+  > reason =
+  > [hooks]
+  > b2x-pretransactionclose.failpush = false
+  > EOF
+
+  $ "$TESTDIR/killdaemons.py" $DAEMON_PIDS
+  $ hg -R other serve -p $HGPORT2 -d --pid-file=other.pid -E other-error.log
+  $ cat other.pid >> $DAEMON_PIDS
+
+  $ hg -R main push other -r e7ec4e813ba6
+  pushing to other
+  searching for changes
+  transaction abort!
+  rollback completed
+  abort: b2x-pretransactionclose.failpush hook exited with status 1
+  [255]
+
+  $ hg -R main push ssh://user@dummy/other -r e7ec4e813ba6
+  pushing to ssh://user@dummy/other
+  searching for changes
+  abort: b2x-pretransactionclose.failpush hook exited with status 1
+  remote: transaction abort!
+  remote: rollback completed
+  [255]
+
+  $ hg -R main push http://localhost:$HGPORT2/ -r e7ec4e813ba6
+  pushing to http://localhost:$HGPORT2/
+  searching for changes
+  abort: b2x-pretransactionclose.failpush hook exited with status 1
+  [255]
+
+