revision.c: use commit-slab for show_source

Instead of relying on commit->util to store the source string, let the
user provide a commit-slab to store the source strings in.

It's done so that commit->util can be removed. See more explanation in
the commit that removes commit->util.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/revision.c b/revision.c
index 1cff118..be8fe7d 100644
--- a/revision.c
+++ b/revision.c
@@ -29,6 +29,8 @@ volatile show_early_output_fn_t show_early_output;
 static const char *term_bad;
 static const char *term_good;
 
+implement_shared_commit_slab(revision_sources, char *);
+
 void show_object_with_name(FILE *out, struct object *obj, const char *name)
 {
 	const char *p;
@@ -255,14 +257,19 @@ static struct commit *handle_commit(struct rev_info *revs,
 	 */
 	if (object->type == OBJ_COMMIT) {
 		struct commit *commit = (struct commit *)object;
+
 		if (parse_commit(commit) < 0)
 			die("unable to parse commit %s", name);
 		if (flags & UNINTERESTING) {
 			mark_parents_uninteresting(commit);
 			revs->limited = 1;
 		}
-		if (revs->show_source && !commit->util)
-			commit->util = xstrdup(name);
+		if (revs->sources) {
+			char **slot = revision_sources_at(revs->sources, commit);
+
+			if (!*slot)
+				*slot = xstrdup(name);
+		}
 		return commit;
 	}
 
@@ -814,8 +821,12 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 			}
 			return -1;
 		}
-		if (revs->show_source && !p->util)
-			p->util = commit->util;
+		if (revs->sources) {
+			char **slot = revision_sources_at(revs->sources, p);
+
+			if (!*slot)
+				*slot = *revision_sources_at(revs->sources, commit);
+		}
 		p->object.flags |= left_flag;
 		if (!(p->object.flags & SEEN)) {
 			p->object.flags |= SEEN;