--template options: file_adds

[Ralph Douglass]

I'm trying to get a list of modified files from a specific revision, so 
that I can write a hook which emails only on mods.

I was looking at http://hgbook.red-bean.com/hgbookch11.html, and it 
seemed like the best way to do it was call:
hg log -r <some revision> --template '{files}'
hg log -r <some revision> --template '{file_adds}'
hg log -r <some revision> --template '{file_dels}'

and then do some munging to subtract the adds and dels from all files.  
But it seems that when I do this, file_adds is always empty.  I tried 
with it a brand new repo too.  I'm testing this on osx 10.4, using 0.9.5 
from macports.  Does someone have a better way to do what I want, or any 
suggestions on what I need to do to get file_adds to list something?

Thanks,

Ralph