[BUG] git log -S not respecting --no-textconv

Hi,

It seems the command "git log --no-textconv -Sfoo" still runs the
textconv filter (noticed because I have a broken textconv filter that
lets "git log -S" error out).

Steps to reproduce:

Create a repo with *.txt file(s) in it
$ echo '*.txt diff=wrong' > .gitattributes

An incorrect textconv filter errors out as expected:

$ git -c diff.wrong.textconv='xxx' log -Sfoo 
error: cannot run xxx: No such file or directory
fatal: unable to read files to diff

but --no-textconv has no effect:

$ git -c diff.wrong.textconv='xxx' log --no-textconv -Sfoo
error: cannot run xxx: No such file or directory
fatal: unable to read files to diff

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/