bug/feature request: apply textconv in "git add -p" diff output

Hi,

I use git to manage bdf font files. It it quite cryptic so textconv
for diff output makes it much easier to keep track of changes. The
only problem is that "git add -p" does not seems to use textconv, so I
have to run in parallel "git diff" and "git add -p", then add chunks
accordingly. Can somebody add textconv support to "git add -p" please?
I'm not so good at Perl to do the job.

Thanks,
-- 
Duy