# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1165430727 21600
# Node ID 302ffecdd7262e5f1a2911504e6afe4dc4c60a45
# Parent  792e61e9a00acf107f454d8d276f10e826bbaf06# Parent  2aef481ac73c320018fc0a14c200a0e5266e3eac
Merge with crew

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2215,7 +2215,7 @@ def tag(ui, repo, name, rev_=None, **opt
     necessary.  The file '.hg/localtags' is used for local tags (not
     shared among repositories).
     """
-    if name in ['tip', '.']:
+    if name in ['tip', '.', 'null']:
         raise util.Abort(_("the name '%s' is reserved") % name)
     if rev_ is not None:
         ui.warn(_("use of 'hg tag NAME [REV]' is deprecated, "
@@ -2275,8 +2275,7 @@ def unbundle(ui, repo, fname, **opts):
     modheads = repo.addchangegroup(gen, 'unbundle', 'bundle:' + fname)
     return postincoming(ui, repo, modheads, opts['update'])
 
-def update(ui, repo, node=None, merge=False, clean=False, force=None,
-           branch=None):
+def update(ui, repo, node=None, clean=False, branch=None):
     """update or merge working directory
 
     Update the working directory to the specified revision.
@@ -2721,10 +2720,8 @@ table = {
         (update,
          [('b', 'branch', '',
            _('checkout the head of a specific branch (DEPRECATED)')),
-          ('m', 'merge', None, _('allow merging of branches (DEPRECATED)')),
-          ('C', 'clean', None, _('overwrite locally modified files')),
-          ('f', 'force', None, _('force a merge with outstanding changes'))],
-         _('hg update [-C] [-f] [REV]')),
+          ('C', 'clean', None, _('overwrite locally modified files'))],
+         _('hg update [-C] [REV]')),
     "verify": (verify, [], _('hg verify')),
     "version": (version_, [], _('hg version')),
 }
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -376,6 +376,8 @@ class localrepository(repo.repository):
             key = self.dirstate.parents()[0]
             if key == nullid:
                 raise repo.RepoError(_("no revision checked out"))
+        elif key == 'null':
+            return nullid
         n = self.changelog._match(key)
         if n:
             return n
@@ -1740,8 +1742,13 @@ class localrepository(repo.repository):
 
     def addchangegroup(self, source, srctype, url):
         """add changegroup to repo.
-        returns number of heads modified or added + 1."""
 
+        return values:
+        - nothing changed or no source: 0
+        - more heads than before: 1+added heads (2..n)
+        - less heads than before: -1-removed heads (-2..-n)
+        - number of heads stays the same: 1
+        """
         def csmap(x):
             self.ui.debug(_("add changeset %s\n") % short(x))
             return cl.count()
@@ -1834,7 +1841,11 @@ class localrepository(repo.repository):
                 self.hook("incoming", node=hex(self.changelog.node(i)),
                           source=srctype, url=url)
 
-        return newheads - oldheads + 1
+        # never return 0 here:
+        if newheads < oldheads:
+            return newheads - oldheads - 1
+        else:
+            return newheads - oldheads + 1
 
 
     def stream_in(self, remote):
diff --git a/tests/test-push-warn b/tests/test-push-warn
--- a/tests/test-push-warn
+++ b/tests/test-push-warn
@@ -47,10 +47,11 @@ done
 HGMERGE=true hg merge 3
 hg ci -m c-d -d "1000000 0"
 
-hg push ../c
-hg push -r 2 ../c
-hg push -r 3 -r 4 ../c
-hg push -f -r 3 -r 4 ../c
-hg push -r 5 ../c
+hg push ../c; echo $?
+hg push -r 2 ../c; echo $?
+hg push -r 3 ../c; echo $?
+hg push -r 3 -r 4 ../c; echo $?
+hg push -f -r 3 -r 4 ../c; echo $?
+hg push -r 5 ../c; echo $?
 
 exit 0
diff --git a/tests/test-push-warn.out b/tests/test-push-warn.out
--- a/tests/test-push-warn.out
+++ b/tests/test-push-warn.out
@@ -33,22 +33,32 @@ pushing to ../c
 searching for changes
 abort: push creates new remote branches!
 (did you forget to merge? use push -f to force)
+0
 pushing to ../c
 searching for changes
 no changes found
+0
 pushing to ../c
 searching for changes
 abort: push creates new remote branches!
 (did you forget to merge? use push -f to force)
+0
+pushing to ../c
+searching for changes
+abort: push creates new remote branches!
+(did you forget to merge? use push -f to force)
+0
 pushing to ../c
 searching for changes
 adding changesets
 adding manifests
 adding file changes
 added 2 changesets with 2 changes to 1 files (+2 heads)
+0
 pushing to ../c
 searching for changes
 adding changesets
 adding manifests
 adding file changes
 added 1 changesets with 1 changes to 1 files (-1 heads)
+0