diff -r 4e34a723115b -r f46a41006136 hgext/obsolete.py
--- a/hgext/obsolete.py	Wed Aug 08 15:40:09 2012 +0200
+++ b/hgext/obsolete.py	Wed Aug 08 16:51:45 2012 +0200
@@ -988,35 +988,28 @@
                     # targetrev. If a source revision is mapped to targetrev
                     # or to another rebased revision, it must have been
                     # removed.
-                    targetrev = repo[repo._rebasetarget].rev()
-                    newrevs = set([targetrev])
-                    replacements = {}
-                    for rev, newrev in sorted(repo._rebasestate.items()):
-                        oldnode = repo[rev].node()
-                        if newrev not in newrevs:
-                            newnode = repo[newrev].node()
-                            newrevs.add(newrev)
-                        else:
-                            newnode = nullid
-                        replacements[oldnode] = newnode
-
+                    markers = []
                     if kwargs.get('collapse'):
-                        newnodes = set(n for n in replacements.values() if n != nullid)
-                        if newnodes:
-                            # Collapsing into more than one revision?
-                            assert len(newnodes) == 1, newnodes
-                            newnode = newnodes.pop()
-                            markers = [(repo[r], (repo[newnode],))
-                                       for r in replacements]
+                        # collapse assume revision disapear because they are all
+                        # in the created revision
+                        newrevs = set(repo._rebasestate.values())
+                        newrevs.remove(repo._rebasetarget)
+                        if newrevs:
+                            # we create new revision.
+                            # A single one by --collapse design
+                            assert len(newrevs) == 1
+                            new = tuple(repo[n] for n in newrevs)
                         else:
-                            newnode = nullid
-                            markers = [(repo[r], ())
-                                       for r in replacements]
-                        createmarkers(repo, markers)
-                    elif replacements:
-                        markers = [(repo[o], (() if n == nullid else (repo[n],)))
-                                   for o, n in replacements.iteritems()]
-                        createmarkers(repo, markers)
+                            # every body died. no new changeset created
+                            new = (repo[repo._rebasetarget],)
+                        for rev, newrev in sorted(repo._rebasestate.items()):
+                            markers.append((repo[rev], new))
+                    else:
+                        # no collapse assume revision disapear because they are
+                        # contained in parent
+                        for rev, newrev in sorted(repo._rebasestate.items()):
+                            markers.append((repo[rev], (repo[newrev],)))
+                    createmarkers(repo, markers)
             return res
         finally:
             l.release()