Merge branch 'jc/diff-index-unpack'

* jc/diff-index-unpack:
  diff-index: pass pathspec down to unpack-trees machinery
  unpack-trees: allow pruning with pathspec
  traverse_trees(): allow pruning with pathspec

diff-lib.c

@@ -468,6 +468,7 @@ static int diff_cache(struct rev_info *revs,
 	opts.unpack_data = revs;
 	opts.src_index = &the_index;
 	opts.dst_index = NULL;
+	opts.pathspec = &revs->diffopt.pathspec;
 
 	init_tree_desc(&t, tree->buffer, tree->size);
 	return unpack_trees(1, &t, &opts);