fix pager.diff with diff --no-index

git-diff does not rely on the git wrapper to setup its
pager; instead, it sets it up on its own after seeing
whether --quiet or --exit-code has been specified.  After
diff_no_index was split off from cmd_diff, commit b3fde6c
(git diff --no-index: default to page like other diff
frontends, 2008-05-26) duplicated the one-liner from
cmd_diff to turn on the pager.

Later, commit 8f0359f (Allow pager of diff command be
enabled/disabled, 2008-07-21) taught the the version in
cmd_diff to respect the pager.diff config, but the version
in diff_no_index was left behind. This meant that

  git -c pager.diff=0 diff a b

would not use a pager, but

  git -c pager.diff=0 diff --no-index a b

would.  Let's fix it by factoring out a common function.

While we're there, let's update the antiquated comment,
which claims that the pager interferes with propagating the
exit code; this has not been the case since ea27a18 (spawn
pager via run_command interface, 2008-07-22).

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

1 files changed, 2 insertions, 0 deletions

diff --git a/builtin.h b/builtin.h
index 857b9c8aa..999ba3be7 100644
--- a/builtin.h
+++ b/builtin.h
@@ -41,6 +41,8 @@ int copy_note_for_rewrite(struct notes_rewrite_cfg *c,
 void finish_copy_notes_for_rewrite(struct notes_rewrite_cfg *c);
 
 extern int check_pager_config(const char *cmd);
+struct diff_options;
+extern void setup_diff_pager(struct diff_options *);
 
 extern int textconv_object(const char *path, unsigned mode, const unsigned char *sha1, char **buf, unsigned long *buf_size);