read_file() was a useful function if you want to work with the xdiff stuff,
so it was renamed and put into a more central place.
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This refactors the line-by-line callback mechanism used in
combine-diff so that other programs can reuse it more easily.
Signed-off-by: Junio C Hamano <junkio@cox.net>