diff -r 823a7d79ef82 -r 434e5bd615fc hgext/extdiff.py
--- a/hgext/extdiff.py	Mon Oct 15 09:43:34 2012 -0700
+++ b/hgext/extdiff.py	Tue Oct 16 11:43:15 2012 -0700
@@ -329,3 +329,5 @@
         cmdtable[cmd] = (save(cmd, path, diffopts),
                          cmdtable['extdiff'][1][1:],
                          _('hg %s [OPTION]... [FILE]...') % cmd)
+
+commands.inferrepo += " extdiff"