git: update to v2.19.1

Update to git version v2.19.1. Required changes follow upstream commits:

* commit: add repository argument to get_cached_commit_buffer
  (3ce85f7e5a41116145179f0fae2ce6d86558d099)

* commit: add repository argument to lookup_commit_reference
  (2122f6754c93be8f02bfb5704ed96c88fc9837a8)

* object: add repository argument to parse_object
  (109cd76dd3467bd05f8d2145b857006649741d5c)

* tag: add repository argument to deref_tag
  (a74093da5ed601a09fa158e5ba6f6f14c1142a3e)

* tag: add repository argument to lookup_tag
  (ce71efb713f97f476a2d2ab541a0c73f684a5db3)

* tree: add repository argument to lookup_tree
  (f86bcc7b2ce6cad68ba1a48a528e380c6126705e)

* archive.c: avoid access to the_index
  (b612ee202a48f129f81f8f6a5af6cf71d1a9caef)

* for_each_*_object: move declarations to object-store.h
  (0889aae1cd18c1804ba01c1a4229e516dfb9fe9b)

Signed-off-by: Christian Hesse <mail@eworm.de>

ui-blob.c

@@ -56,7 +56,7 @@ int cgit_ref_path_exists(const char *path, const char *ref, int file_only)
 		goto done;
 	if (oid_object_info(the_repository, &oid, &size) != OBJ_COMMIT)
 		goto done;
-	read_tree_recursive(lookup_commit_reference(&oid)->maybe_tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+	read_tree_recursive(lookup_commit_reference(the_repository, &oid)->maybe_tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
 
 done:
 	free(path_items.match);
@@ -89,7 +89,7 @@ int cgit_print_file(char *path, const char *head, int file_only)
 		return -1;
 	type = oid_object_info(the_repository, &oid, &size);
 	if (type == OBJ_COMMIT) {
-		commit = lookup_commit_reference(&oid);
+		commit = lookup_commit_reference(the_repository, &oid);
 		read_tree_recursive(commit->maybe_tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
 		if (!walk_tree_ctx.found_path)
 			return -1;
@@ -145,7 +145,7 @@ void cgit_print_blob(const char *hex, char *path, const char *head, int file_onl
 	type = oid_object_info(the_repository, &oid, &size);
 
 	if ((!hex) && type == OBJ_COMMIT && path) {
-		commit = lookup_commit_reference(&oid);
+		commit = lookup_commit_reference(the_repository, &oid);
 		read_tree_recursive(commit->maybe_tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
 		type = oid_object_info(the_repository, &oid, &size);
 	}