patch-id: use stable patch-id for rebases

Git doesn't persist patch-ids during the rebase process, so there is
no need to specifically invoke the unstable variant. Use the stable
logic for all internal patch-id calculations to minimize the number of
code paths and improve test coverage.

Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/log.c

@@ -1694,7 +1694,7 @@ static void prepare_bases(struct base_tree_info *bases,
 		struct object_id *patch_id;
 		if (*commit_base_at(&commit_base, commit))
 			continue;
-		if (commit_patch_id(commit, &diffopt, &oid, 0, 1))
+		if (commit_patch_id(commit, &diffopt, &oid, 0))
 			die(_("cannot get patch id"));
 		ALLOC_GROW(bases->patch_id, bases->nr_patch_id + 1, bases->alloc_patch_id);
 		patch_id = bases->patch_id + bases->nr_patch_id;

diff.c

@@ -6174,7 +6174,7 @@ static void patch_id_add_mode(git_hash_ctx *ctx, unsigned mode)
 }
 
 /* returns 0 upon success, and writes result into oid */
-static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
+static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
@@ -6261,21 +6261,17 @@ static int diff_get_patch_id(struct diff_options *options, struct object_id *oid
 				return error("unable to generate patch-id diff for %s",
 					     p->one->path);
 		}
-		if (stable)
-			flush_one_hunk(oid, &ctx);
+		flush_one_hunk(oid, &ctx);
 	}
 
-	if (!stable)
-		the_hash_algo->final_oid_fn(oid, &ctx);
-
 	return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
+int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
-	int result = diff_get_patch_id(options, oid, diff_header_only, stable);
+	int result = diff_get_patch_id(options, oid, diff_header_only);
 
 	for (i = 0; i < q->nr; i++)
 		diff_free_filepair(q->queue[i]);

diff.h

@@ -634,7 +634,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option);
 int run_diff_index(struct rev_info *revs, unsigned int option);
 
 int do_diff_cache(const struct object_id *, struct diff_options *);
-int diff_flush_patch_id(struct diff_options *, struct object_id *, int, int);
+int diff_flush_patch_id(struct diff_options *, struct object_id *, int);
 void flush_one_hunk(struct object_id *result, git_hash_ctx *ctx);
 
 int diff_result_code(struct diff_options *, int);

patch-ids.c

@@ -11,7 +11,7 @@ static int patch_id_defined(struct commit *commit)
 }
 
 int commit_patch_id(struct commit *commit, struct diff_options *options,
-		    struct object_id *oid, int diff_header_only, int stable)
+		    struct object_id *oid, int diff_header_only)
 {
 	if (!patch_id_defined(commit))
 		return -1;
@@ -22,7 +22,7 @@ int commit_patch_id(struct commit *commit, struct diff_options *options,
 	else
 		diff_root_tree_oid(&commit->object.oid, "", options);
 	diffcore_std(options);
-	return diff_flush_patch_id(options, oid, diff_header_only, stable);
+	return diff_flush_patch_id(options, oid, diff_header_only);
 }
 
 /*
@@ -48,11 +48,11 @@ static int patch_id_neq(const void *cmpfn_data,
 	b = container_of(entry_or_key, struct patch_id, ent);
 
 	if (is_null_oid(&a->patch_id) &&
-	    commit_patch_id(a->commit, opt, &a->patch_id, 0, 0))
+	    commit_patch_id(a->commit, opt, &a->patch_id, 0))
 		return error("Could not get patch ID for %s",
 			oid_to_hex(&a->commit->object.oid));
 	if (is_null_oid(&b->patch_id) &&
-	    commit_patch_id(b->commit, opt, &b->patch_id, 0, 0))
+	    commit_patch_id(b->commit, opt, &b->patch_id, 0))
 		return error("Could not get patch ID for %s",
 			oid_to_hex(&b->commit->object.oid));
 	return !oideq(&a->patch_id, &b->patch_id);
@@ -82,7 +82,7 @@ static int init_patch_id_entry(struct patch_id *patch,
 	struct object_id header_only_patch_id;
 
 	patch->commit = commit;
-	if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1, 0))
+	if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1))
 		return -1;
 
 	hashmap_entry_init(&patch->ent, oidhash(&header_only_patch_id));

patch-ids.h

@@ -20,7 +20,7 @@ struct patch_ids {
 };
 
 int commit_patch_id(struct commit *commit, struct diff_options *options,
-		    struct object_id *oid, int, int);
+		    struct object_id *oid, int);
 int init_patch_ids(struct repository *, struct patch_ids *);
 int free_patch_ids(struct patch_ids *);