merge-recursive: remove unnecessary oid_eq function

Back when merge-recursive was first introduced in commit 6d297f8
(Status update on merge-recursive in C, 2006-07-08), it created a
sha_eq() function.  This function pre-dated the introduction of
hashcmp() to cache.h by about a month, but was switched over to using
hashcmp() as part of commit 9047ebb (Split out merge_recursive() to
merge-recursive.c, 2008-08-12).  In commit b4da9d6 (merge-recursive:
convert leaf functions to use struct object_id, 2016-06-24), sha_eq() was
renamed to oid_eq() and its hashcmp() call was switched to oideq().

oid_eq() is basically just a wrapper around oideq() that has some extra
checks to protect against NULL arguments or to allow short-circuiting if
one of the arguments is NULL.  I don't know if any caller ever tried to
call with NULL arguments, but certainly none do now which means the
extra checks serve no purpose.  (Also, if these checks were genuinely
useful, then they probably should be added to the main oideq() so all
callers could benefit from them.)

Reduce the cognitive overhead of having both oid_eq() and oideq(), by
getting rid of merge-recursive's special oid_eq() wrapper.

Signed-off-by: Elijah Newren <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: newren

merge-recursive.c

@@ -224,17 +224,6 @@ static struct commit *make_virtual_commit(struct repository *repo,
 	return commit;
 }
 
-/*
- * Since we use get_tree_entry(), which does not put the read object into
- * the object pool, we cannot rely on a == b.
- */
-static int oid_eq(const struct object_id *a, const struct object_id *b)
-{
-	if (!a && !b)
-		return 2;
-	return a && b && oideq(a, b);
-}
-
 enum rename_type {
 	RENAME_NORMAL = 0,
 	RENAME_VIA_DIR,
@@ -805,7 +794,7 @@ static int was_tracked_and_matches(struct merge_options *opt, const char *path,
 
 	/* See if the file we were tracking before matches */
 	ce = opt->priv->orig_index.cache[pos];
-	return (oid_eq(&ce->oid, &blob->oid) && ce->ce_mode == blob->mode);
+	return (oideq(&ce->oid, &blob->oid) && ce->ce_mode == blob->mode);
 }
 
 /*
@@ -1317,7 +1306,7 @@ static int merge_mode_and_contents(struct merge_options *opt,
 			oidcpy(&result->blob.oid, &b->oid);
 		}
 	} else {
-		if (!oid_eq(&a->oid, &o->oid) && !oid_eq(&b->oid, &o->oid))
+		if (!oideq(&a->oid, &o->oid) && !oideq(&b->oid, &o->oid))
 			result->merge = 1;
 
 		/*
@@ -1333,9 +1322,9 @@ static int merge_mode_and_contents(struct merge_options *opt,
 			}
 		}
 
-		if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &o->oid))
+		if (oideq(&a->oid, &b->oid) || oideq(&a->oid, &o->oid))
 			oidcpy(&result->blob.oid, &b->oid);
-		else if (oid_eq(&b->oid, &o->oid))
+		else if (oideq(&b->oid, &o->oid))
 			oidcpy(&result->blob.oid, &a->oid);
 		else if (S_ISREG(a->mode)) {
 			mmbuffer_t result_buf;
@@ -1368,7 +1357,7 @@ static int merge_mode_and_contents(struct merge_options *opt,
 			switch (opt->recursive_variant) {
 			case MERGE_VARIANT_NORMAL:
 				oidcpy(&result->blob.oid, &a->oid);
-				if (!oid_eq(&a->oid, &b->oid))
+				if (!oideq(&a->oid, &b->oid))
 					result->clean = 0;
 				break;
 			case MERGE_VARIANT_OURS:
@@ -2778,15 +2767,15 @@ static int process_renames(struct merge_options *opt,
 			dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
 			try_merge = 0;
 
-			if (oid_eq(&src_other.oid, &null_oid) &&
+			if (oideq(&src_other.oid, &null_oid) &&
 			    ren1->dir_rename_original_type == 'A') {
 				setup_rename_conflict_info(RENAME_VIA_DIR,
 							   opt, ren1, NULL);
-			} else if (oid_eq(&src_other.oid, &null_oid)) {
+			} else if (oideq(&src_other.oid, &null_oid)) {
 				setup_rename_conflict_info(RENAME_DELETE,
 							   opt, ren1, NULL);
 			} else if ((dst_other.mode == ren1->pair->two->mode) &&
-				   oid_eq(&dst_other.oid, &ren1->pair->two->oid)) {
+				   oideq(&dst_other.oid, &ren1->pair->two->oid)) {
 				/*
 				 * Added file on the other side identical to
 				 * the file being renamed: clean merge.
@@ -2801,7 +2790,7 @@ static int process_renames(struct merge_options *opt,
 						      1, /* update_cache */
 						      0  /* update_wd    */))
 					clean_merge = -1;
-			} else if (!oid_eq(&dst_other.oid, &null_oid)) {
+			} else if (!oideq(&dst_other.oid, &null_oid)) {
 				/*
 				 * Probably not a clean merge, but it's
 				 * premature to set clean_merge to 0 here,
@@ -2979,7 +2968,7 @@ static int blob_unchanged(struct merge_options *opt,
 
 	if (a->mode != o->mode)
 		return 0;
-	if (oid_eq(&o->oid, &a->oid))
+	if (oideq(&o->oid, &a->oid))
 		return 1;
 	if (!renormalize)
 		return 0;
@@ -3420,7 +3409,7 @@ static int merge_trees_internal(struct merge_options *opt,
 					       opt->subtree_shift);
 	}
 
-	if (oid_eq(&merge_base->object.oid, &merge->object.oid)) {
+	if (oideq(&merge_base->object.oid, &merge->object.oid)) {
 		output(opt, 0, _("Already up to date!"));
 		*result = head;
 		return 1;