bookmark: use 'divergent2delete' in checkconflict

checkconflict used to also do some bookmark deletion in case of divergence. It
is a bit suspicious given the function name, but it's not the goal of this
series.

In order to unify bookmarks changing, checkconflict now return the list of
divergent bookmarks to clean up and the callers must clean them by calling
applyphases.

mercurial/bookmarks.py

@@ -183,13 +183,15 b' class bmstore(dict):'
 
         If force is supplied, then forcibly move the bookmark to a new commit
         regardless if it is a move forward.
+
+        If divergent bookmark are to be deleted, they will be returned as list.
         """
         cur = self._repo.changectx('.').node()
         if mark in self and not force:
             if target:
                 if self[mark] == target and target == cur:
                     # re-activating a bookmark
-                    return
+                    return []
                 rev = self._repo[target].rev()
                 anc = self._repo.changelog.ancestors([rev])
                 bmctx = self._repo[self[mark]]
@@ -200,17 +202,16 b' class bmstore(dict):'
                 # the bookmark across branches when a revision is specified
                 # that contains a divergent bookmark
                 if bmctx.rev() not in anc and target in divs:
-                    deletedivergent(self._repo, [target], mark)
-                    return
+                    return divergent2delete(self._repo, [target], mark)
 
                 deletefrom = [b for b in divs
                               if self._repo[b].rev() in anc or b == target]
-                deletedivergent(self._repo, deletefrom, mark)
+                delbms = divergent2delete(self._repo, deletefrom, mark)
                 if validdest(self._repo, bmctx, self._repo[target]):
                     self._repo.ui.status(
                         _("moving bookmark '%s' forward from %s\n") %
                         (mark, short(bmctx.node())))
-                    return
+                    return delbms
             raise error.Abort(_("bookmark '%s' already exists "
                                 "(use -f to force)") % mark)
         if ((mark in self._repo.branchmap() or
@@ -228,6 +229,7 b' class bmstore(dict):'
                       "(did you leave a -r out of an 'hg bookmark' "
                       "command?)\n")
                     % mark)
+        return []
 
 def _readactive(repo, marks):
     """
@@ -747,8 +749,10 b' def rename(repo, tr, old, new, force=Fal'
     mark = checkformat(repo, new)
     if old not in marks:
         raise error.Abort(_("bookmark '%s' does not exist") % old)
-    marks.checkconflict(mark, force)
-    changes = [(mark, marks[old]), (old, None)]
+    changes = []
+    for bm in marks.checkconflict(mark, force):
+        changes.append((bm, None))
+    changes.extend([(mark, marks[old]), (old, None)])
     marks.applychanges(repo, tr, changes)
     if repo._activebookmark == old and not inactive:
         activate(repo, mark)
@@ -778,7 +782,8 b' def addbookmarks(repo, tr, names, rev=No'
         tgt = cur
         if rev:
             tgt = scmutil.revsingle(repo, rev).node()
-        marks.checkconflict(mark, force, tgt)
+        for bm in marks.checkconflict(mark, force, tgt):
+            changes.append((bm, None))
         changes.append((mark, tgt))
     marks.applychanges(repo, tr, changes)
     if not inactive and cur == marks[newact] and not rev: