t3701: add a test for interactive.diffFilter

This feature was added in 01143847db (add--interactive:
allow custom diff highlighting programs, 2016-02-27) but
never tested. Let's add a basic test.

Note that we only apply the filter when color is enabled,
so we have to use test_terminal. This is an open limitation
explicitly mentioned in the original commit. So take this
commit as testing the status quo, and not making a statement
on whether we'd want to enhance that in the future.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions