rebase: abort if *any* commit in rebase set is public

hgext/rebase.py

@@ -326,10 +326,10 b' class rebaseruntime(object):'
             self.ui.status(_('nothing to rebase\n'))
             return _nothingtorebase()
 
-        root = min(rebaseset)
-        if not self.keepf and not self.repo[root].mutable():
+        for root in self.repo.set('roots(%ld)', rebaseset):
+            if not self.keepf and not root.mutable():
             raise error.Abort(_("can't rebase public changeset %s")
-                             % self.repo[root],
+                                  % root,
                              hint=_("see 'hg help phases' for details"))
 
         (self.originalwd, self.target, self.state) = result

tests/test-rebase-scenario-global.t

@@ -329,6 +329,10 b' Check rebasing public changeset'
   abort: can't rebase public changeset e1c4361dd923
   (see 'hg help phases' for details)
   [255]
+  $ hg rebase -d 5 -r '1 + (6::)'
+  abort: can't rebase public changeset e1c4361dd923
+  (see 'hg help phases' for details)
+  [255]
 
   $ hg rebase -d 5 -b 6 --keep
   rebasing 6:e1c4361dd923 "C"