The new find_name_gnu() function handles new-style '--- "a/foo"'
patch header lines, leaving find_name() itself a bit less
daunting.
Functional change: do not clobber the p-value when there are not
enough path components in a quoted file name to honor it.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>