discovery: tweak error message for multiple branch heads

mercurial/discovery.py

@@ -313,8 +313,8 b' def checkheads(repo, remote, outgoing, r'
             if 1 < len(newhs):
                 dhs = list(newhs)
                 if error is None:
-                    error = (_("push creates multiple headed new branch '%s'")
-                             % (branch))
+                    error = (_("push creates new branch '%s' "
+                               "with multiple heads") % (branch))
                     hint = _("merge or"
                              " see \"hg help push\" for details about"
                              " pushing new heads")

tests/test-push-warn.t

@@ -367,7 +367,7 b' Pushing muliple headed new branch:'
   $ hg push --branch f --new-branch ../f
   pushing to ../f
   searching for changes
-  abort: push creates multiple headed new branch 'f'
+  abort: push creates new branch 'f' with multiple heads
   (merge or see "hg help push" for details about pushing new heads)
   [255]
   $ hg push --branch f --new-branch --force ../f