[PATCH 6 of 6] checkheads: take future obsoleted heads in account

[pierre-yves.david at logilab.fr]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at logilab.fr>
# Date 1342540769 -7200
# Node ID aeb32045c7ada63c7f570bd5dc410381c12dce6c
# Parent  e684aa58b85911fa1f6f8f0f9571a8b191bf6a3d
checkheads: take future obsoleted heads in account.

If we push some successors they will likely create a new head on remote. However
as the obsoleted head will disappear after the push we are not really increasing
the number of heads.

There is several case which will lead to extra being actually pushed. But this
first changeset aims to be simple. See the inline comment for details.

Without this change, you need to push --force every time you want to push a newer
version which is very error prone.

The remote side still display +n heads on unbundle because it does not have the
obsolete marker at unbundle time.

diff --git a/mercurial/discovery.py b/mercurial/discovery.py
--- a/mercurial/discovery.py
+++ b/mercurial/discovery.py
@@ -5,11 +5,11 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from node import nullid, short
 from i18n import _
-import util, setdiscovery, treediscovery, phases
+import util, setdiscovery, treediscovery, phases, obsolete
 
 def findcommonincoming(repo, remote, heads=None, force=False):
     """Return a tuple (common, anyincoming, heads) used to identify the common
     subset of nodes between repo and remote.
 
@@ -264,20 +264,47 @@ def checkheads(repo, remote, outgoing, r
     # 3. Check for new heads.
     # If there are more heads after the push than before, a suitable
     # error message, depending on unsynced status, is displayed.
     error = None
     unsynced = False
+    allmissing = set(outgoing.missing)
     for branch, heads in headssum.iteritems():
         if heads[0] is None:
             # Maybe we should abort if we push more that one head
             # for new branches ?
             continue
         if heads[2]:
             unsynced = True
         oldhs = set(heads[0])
-        newhs = set(heads[1])
+        candidate_newhs = set(heads[1])
+        # add unsynced data
+        oldhs.update(heads[2])
+        candidate_newhs.update(heads[2])
         dhs = None
+        if repo.obsstore:
+            # remove future heads which are actually obsolete by another
+            # pushed element:
+            #
+            # XXX There is several case this case does not handle properly
+            #
+            # (1) if <nh> is public, it won't be affected by obsolete marker
+            #     and a new is created
+            #
+            # (2) if the new heads have ancestors which are not obsolete and
+            #     not ancestors of any other heads we will have a new head too.
+            #
+            # This two case will be easy to handle for know changeset but much
+            # more tricky for unsynced changes.
+            newhs = set()
+            for nh in candidate_newhs:
+                for suc in obsolete.anysuccessors(repo.obsstore, nh):
+                    if suc != nh and suc in allmissing:
+                        break
+                else:
+                    newhs.add(nh)
+        else:
+            newhs = candidate_newhs
         if len(newhs) > len(oldhs):
             # strip updates to existing remote heads from the new heads list
             dhs = list(newhs - bookmarkedheads - oldhs)
         if dhs:
             if error is None:
diff --git a/tests/test-obsolete.t b/tests/test-obsolete.t
--- a/tests/test-obsolete.t
+++ b/tests/test-obsolete.t
@@ -355,5 +355,52 @@ no warning displayed
   $ hg push ../tmpf
   pushing to ../tmpf
   searching for changes
   no changes found
   [1]
+
+Do not warn about new head when the new head is a successors of a remote one
+
+  $ hg glog
+  @  changeset:   5:6e572121998e
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     add original_e
+  |
+  x  changeset:   4:7c694bff0650
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     add original_d
+  |
+  o  changeset:   3:5601fb93a350
+  |  parent:      1:7c3bad9141dc
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     add new_3_c
+  |
+  | o  changeset:   2:245bde4270cd
+  |/   user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     add original_c
+  |
+  o  changeset:   1:7c3bad9141dc
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     add b
+  |
+  o  changeset:   0:1f0dee641bb7
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     add a
+  
+  $ hg up -q 'desc(new_3_c)'
+  $ mkcommit obsolete_e
+  created new head
+  $ hg debugobsolete `getid 'original_e'` `getid 'obsolete_e'`
+  $ hg push ../tmpf
+  pushing to ../tmpf
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)