index: include TYPECHANGE in the diff

Without this option, we would not be able to catch exec bit changes.

src/index.c

@@ -2681,8 +2681,9 @@ static int index_apply_to_wd_diff(git_index *index, int action, const git_strarr
 	if ((error = git_pathspec__init(&ps, paths)) < 0)
 		return error;
 
+	opts.flags = GIT_DIFF_INCLUDE_TYPECHANGE;
 	if (action == INDEX_ACTION_ADDALL) {
-		opts.flags = GIT_DIFF_INCLUDE_UNTRACKED | GIT_DIFF_RECURSE_IGNORED_DIRS;
+		opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED | GIT_DIFF_RECURSE_IGNORED_DIRS;
 		if (flags == GIT_INDEX_ADD_FORCE)
 			opts.flags |= GIT_DIFF_INCLUDE_IGNORED;
 	}

tests/index/addall.c

@@ -193,6 +193,19 @@ void test_index_addall__repo_lifecycle(void)
 	cl_repo_commit_from_index(NULL, g_repo, NULL, 0, "first commit");
 	check_status(g_repo, 0, 0, 0, 3, 0, 0, 1);
 
+	if (cl_repo_get_bool(g_repo, "core.filemode")) {
+		cl_git_pass(git_index_update_all(index, NULL, NULL, NULL));
+		cl_must_pass(p_chmod(TEST_DIR "/file.zzz", 0777));
+		cl_git_pass(git_index_update_all(index, NULL, NULL, NULL));
+		check_status(g_repo, 0, 0, 1, 3, 0, 0, 1);
+
+		/* go back to what we had before */
+		cl_must_pass(p_chmod(TEST_DIR "/file.zzz", 0666));
+		cl_git_pass(git_index_update_all(index, NULL, NULL, NULL));
+		check_status(g_repo, 0, 0, 0, 3, 0, 0, 1);
+	}
+
+
 	/* attempt to add an ignored file - does nothing */
 	strs[0] = "file.foo";
 	cl_git_pass(git_index_add_all(index, &paths, 0, NULL, NULL));