diff -r 4c287332e03b -r c2041f80f22a mercurial/commands.py
--- a/mercurial/commands.py	Wed Jul 22 18:08:02 2009 -0500
+++ b/mercurial/commands.py	Wed Jul 22 18:27:23 2009 -0500
@@ -1381,6 +1381,8 @@
     closed = opts.get('closed')
     hideinactive, _heads = opts.get('active'), None
     if not branchrevs:
+        if closed:
+            raise error.Abort(_('you must specify a branch to use --closed'))
         # Assume we're looking repo-wide heads if no revs were specified.
         heads = repo.heads(start)
     else:
@@ -3210,7 +3212,7 @@
          [('a', 'active', False,
            _('show only branches that have unmerged heads')),
           ('c', 'closed', False,
-           _('show normal and closed heads'))],
+           _('show normal and closed branches'))],
          _('[-a]')),
     "bundle":
         (bundle,
@@ -3327,9 +3329,9 @@
         (heads,
          [('r', 'rev', '', _('show only heads which are descendants of REV')),
           ('a', 'active', False,
-           _('show only the active heads from open branches')),
+           _('show only the active branch heads from open branches')),
           ('c', 'closed', False,
-           _('show normal and closed heads')),
+           _('show normal and closed branch heads')),
          ] + templateopts,
          _('[-r STARTREV] [REV]...')),
     "help": (help_, [], _('[TOPIC]')),