What's the url to view a file at tip through the web interface?

[Rob Landley]

Using 0.9.3, I'm trying to view a file at tip through the web interface.  Not 
a specific version of the file, but a URL to always show the most recent 
version.

Drilling down in my repository through the manifest, I can get:
  http://landley.net/hg/firmware?f=6b6822893f99;file=sources/toys/gcc-uClibc.c

But when I try changing the version to "tip", ala:
  http://landley.net/hg/firmware?f=tip;file=sources/toys/gcc-uClibc.c

Neither f= nor fl= seem to understand "tip", I just get a python backgrace.  I 
suspect I'm doing this wrong, but don't know what the correct syntax is, and 
google is being unhelpful here.

I found this from a year ago:
http://www.arcknowledge.com/gmane.comp.version-control.mercurial.devel/2006-02/msg00051.html

But if it was relevant, I suspect it'd have been merged in the past 12 months.

Any clues?

Rob
-- 
"Perfection is reached, not when there is no longer anything to add, but
when there is no longer anything to take away." - Antoine de Saint-Exupery