diff -r eccbb9980ada -r 30506b894359 mercurial/commands.py
--- a/mercurial/commands.py	Thu Jun 02 00:43:34 2011 +0300
+++ b/mercurial/commands.py	Wed Jun 01 19:12:18 2011 -0500
@@ -13,7 +13,7 @@
 import patch, help, url, encoding, templatekw, discovery
 import archival, changegroup, cmdutil, sshserver, hbisect, hgweb, hgweb.server
 import merge as mergemod
-import minirst, revset
+import minirst, revset, fileset
 import dagparser, context, simplemerge
 import random, setdiscovery, treediscovery, dagutil
 
@@ -1597,6 +1597,13 @@
         localrevs = opts.get('local_head')
         doit(localrevs, remoterevs)
 
+@command('debugfileset', [], ('REVSPEC'))
+def debugfileset(ui, repo, expr):
+    '''parse and apply a fileset specification'''
+    if ui.verbose:
+        tree = fileset.parse(expr)[0]
+        ui.note(tree, "\n")
+
 @command('debugfsinfo', [], _('[PATH]'))
 def debugfsinfo(ui, path = "."):
     """show information detected about current filesystem"""