convert "oidcmp() == 0" to oideq()

Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).

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

1 files changed, 2 insertions, 2 deletions

diff --git a/builtin/merge.c b/builtin/merge.c
index 8f4a5065c2..57abff999b 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1189,7 +1189,7 @@ static int merging_a_throwaway_tag(struct commit *commit)
 	tag_ref = xstrfmt("refs/tags/%s",
 			  ((struct tag *)merge_remote_util(commit)->obj)->tag);
 	if (!read_ref(tag_ref, &oid) &&
-	    !oidcmp(&oid, &merge_remote_util(commit)->obj->oid))
+	    oideq(&oid, &merge_remote_util(commit)->obj->oid))
 		is_throwaway_tag = 0;
 	else
 		is_throwaway_tag = 1;
@@ -1448,7 +1448,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		goto done;
 	} else if (fast_forward != FF_NO && !remoteheads->next &&
 			!common->next &&
-			!oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
+			oideq(&common->item->object.oid, &head_commit->object.oid)) {
 		/* Again the most common case of merging one remote. */
 		struct strbuf msg = STRBUF_INIT;
 		struct commit *commit;