unpack-trees.c: use path_excluded() in check_ok_to_remove()

This function is responsible for determining if a path that is not
tracked is ignored and allow "checkout" to overwrite it as needed.
It used excluded() without checking if higher level directory in the
path is ignored; correct it to use path_excluded() for this check.

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

 * There are uses of lower-level interface excluded_from_list() in
   the codepath for narrow-checkout hack; they are supposed to be
   already checking each level as they descend, and are not touched
   with this patch.

unpack-trees.c

@@ -1016,6 +1016,10 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 			o->el = ⪙
 	}
 
+	if (o->dir) {
+		o->path_exclude_check = xmalloc(sizeof(struct path_exclude_check));
+		path_exclude_check_init(o->path_exclude_check, o->dir);
+	}
 	memset(&o->result, 0, sizeof(o->result));
 	o->result.initialized = 1;
 	o->result.timestamp.sec = o->src_index->timestamp.sec;
@@ -1140,6 +1144,10 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
 done:
 	free_excludes(&el);
+	if (o->path_exclude_check) {
+		path_exclude_check_clear(o->path_exclude_check);
+		free(o->path_exclude_check);
+	}
 	return ret;
 
 return_failed:
@@ -1355,7 +1363,8 @@ static int check_ok_to_remove(const char *name, int len, int dtype,
 	if (ignore_case && icase_exists(o, name, len, st))
 		return 0;
 
-	if (o->dir && excluded(o->dir, name, &dtype))
+	if (o->dir &&
+	    path_excluded(o->path_exclude_check, name, -1, &dtype))
 		/*
 		 * ce->name is explicitly excluded, so it is Ok to
 		 * overwrite it.

unpack-trees.h

@@ -52,6 +52,7 @@ struct unpack_trees_options {
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;
+	struct path_exclude_check *path_exclude_check;
 	struct pathspec *pathspec;
 	merge_fn_t fn;
 	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];