path-walk: create initializer for path lists

The previous change fixed a bug in 'git repack -adf --path-walk' that
was due to an update to how path lists are initialized and missing some
important cases when processing the pending objects.

This change takes the three critical places where path lists are
initialized and combines them into a static method. This simplifies the
callers somewhat while also helping to avoid a missed update in the
future.

The other places where a path list (struct type_and_oid_list) is
initialized is for the following "fixed" lists:

 * Tag objects.
 * Commit objects.
 * Root trees.
 * Tagged trees.
 * Tagged blobs.

These lists are created and consumed in different ways, with only the
root trees being passed into the logic that cares about the
"maybe_interesting" bit. It is appropriate to keep these uses separate.

Signed-off-by: Derrick Stolee <[email protected]>

Author: derrickstolee

path-walk.c

@@ -105,6 +105,24 @@ static void push_to_stack(struct path_walk_context *ctx,
 	prio_queue_put(&ctx->path_stack, xstrdup(path));
 }
 
+static void add_path_to_list(struct path_walk_context *ctx,
+			     const char *path,
+			     enum object_type type,
+			     struct object_id *oid,
+			     int interesting)
+{
+	struct type_and_oid_list *list = strmap_get(&ctx->paths_to_lists, path);
+
+	if (!list) {
+		CALLOC_ARRAY(list, 1);
+		list->type = type;
+		strmap_put(&ctx->paths_to_lists, path, list);
+	}
+
+	list->maybe_interesting |= interesting;
+	oid_array_append(&list->oids, oid);
+}
+
 static int add_tree_entries(struct path_walk_context *ctx,
 			    const char *base_path,
 			    struct object_id *oid)
@@ -129,7 +147,6 @@ static int add_tree_entries(struct path_walk_context *ctx,
 
 	init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
 	while (tree_entry(&desc, &entry)) {
-		struct type_and_oid_list *list;
 		struct object *o;
 		/* Not actually true, but we will ignore submodules later. */
 		enum object_type type = S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB;
@@ -190,17 +207,10 @@ static int add_tree_entries(struct path_walk_context *ctx,
 				continue;
 		}
 
-		if (!(list = strmap_get(&ctx->paths_to_lists, path.buf))) {
-			CALLOC_ARRAY(list, 1);
-			list->type = type;
-			strmap_put(&ctx->paths_to_lists, path.buf, list);
-		}
-		push_to_stack(ctx, path.buf);
-
-		if (!(o->flags & UNINTERESTING))
-			list->maybe_interesting = 1;
+		add_path_to_list(ctx, path.buf, type, &entry.oid,
+				 !(o->flags & UNINTERESTING));
 
-		oid_array_append(&list->oids, &entry.oid);
+		push_to_stack(ctx, path.buf);
 	}
 
 	free_tree_buffer(tree);
@@ -377,16 +387,9 @@ static int setup_pending_objects(struct path_walk_info *info,
 			if (!info->trees)
 				continue;
 			if (pending->path) {
-				struct type_and_oid_list *list;
 				char *path = *pending->path ? xstrfmt("%s/", pending->path)
 							    : xstrdup("");
-				if (!(list = strmap_get(&ctx->paths_to_lists, path))) {
-					CALLOC_ARRAY(list, 1);
-					list->type = OBJ_TREE;
-					strmap_put(&ctx->paths_to_lists, path, list);
-				}
-				list->maybe_interesting = 1;
-				oid_array_append(&list->oids, &obj->oid);
+				add_path_to_list(ctx, path, OBJ_TREE, &obj->oid, 1);
 				free(path);
 			} else {
 				/* assume a root tree, such as a lightweight tag. */
@@ -397,20 +400,10 @@ static int setup_pending_objects(struct path_walk_info *info,
 		case OBJ_BLOB:
 			if (!info->blobs)
 				continue;
-			if (pending->path) {
-				struct type_and_oid_list *list;
-				char *path = pending->path;
-				if (!(list = strmap_get(&ctx->paths_to_lists, path))) {
-					CALLOC_ARRAY(list, 1);
-					list->type = OBJ_BLOB;
-					strmap_put(&ctx->paths_to_lists, path, list);
-				}
-				list->maybe_interesting = 1;
-				oid_array_append(&list->oids, &obj->oid);
-			} else {
-				/* assume a root tree, such as a lightweight tag. */
+			if (pending->path)
+				add_path_to_list(ctx, pending->path, OBJ_BLOB, &obj->oid, 1);
+			else
 				oid_array_append(&tagged_blobs->oids, &obj->oid);
-			}
 			break;
 
 		case OBJ_COMMIT: