1 files changed, 87 insertions, 0 deletions
diff --git a/tests/diff/workdir.c b/tests/diff/workdir.c
index 84c8866e0..9e4608e9d 100644
--- a/tests/diff/workdir.c
+++ b/tests/diff/workdir.c
@@ -1502,3 +1502,90 @@ void test_diff_workdir__with_stale_index(void)
 
 	git_index_free(idx);
 }
+
+static int touch_file(void *payload, git_buf *path)
+{
+	int fd;
+	char b;
+
+	GIT_UNUSED(payload);
+	if (git_path_isdir(path->ptr))
+		return 0;
+
+	cl_assert((fd = p_open(path->ptr, O_RDWR)) >= 0);
+	cl_assert_equal_i(1, p_read(fd, &b, 1));
+	cl_must_pass(p_lseek(fd, 0, SEEK_SET));
+	cl_must_pass(p_write(fd, &b, 1));
+	cl_must_pass(p_close(fd));
+
+	return 0;
+}
+
+static void basic_diff_status(git_diff **out, const git_diff_options *opts)
+{
+	diff_expects exp;
+
+	cl_git_pass(git_diff_index_to_workdir(out, g_repo, NULL, opts));
+
+	memset(&exp, 0, sizeof(exp));
+
+	cl_git_pass(git_diff_foreach(
+		*out, diff_file_cb, diff_hunk_cb, diff_line_cb, &exp));
+
+	cl_assert_equal_i(13, exp.files);
+	cl_assert_equal_i(0, exp.file_status[GIT_DELTA_ADDED]);
+	cl_assert_equal_i(4, exp.file_status[GIT_DELTA_DELETED]);
+	cl_assert_equal_i(4, exp.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(1, exp.file_status[GIT_DELTA_IGNORED]);
+	cl_assert_equal_i(4, exp.file_status[GIT_DELTA_UNTRACKED]);
+}
+
+void test_diff_workdir__can_update_index(void)
+{
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	git_diff *diff = NULL;
+
+	g_repo = cl_git_sandbox_init("status");
+
+	/* touch all the files so stat times are different */
+	{
+		git_buf path = GIT_BUF_INIT;
+		cl_git_pass(git_buf_sets(&path, "status"));
+		cl_git_pass(git_path_direach(&path, 0, touch_file, NULL));
+		git_buf_free(&path);
+	}
+
+	opts.flags |= GIT_DIFF_INCLUDE_IGNORED | GIT_DIFF_INCLUDE_UNTRACKED;
+
+	basic_diff_status(&diff, &opts);
+#ifdef GIT_PERF
+	cl_assert_equal_sz(diff->stat_calls, 13 + 3);
+	cl_assert_equal_sz(diff->oid_calculations, 5);
+	cl_assert_equal_sz(diff->submodule_lookups, 1);
+#endif
+
+	git_diff_free(diff);
+
+	/* now allow diff to update stat cache */
+	opts.flags |= GIT_DIFF_UPDATE_INDEX;
+
+	basic_diff_status(&diff, &opts);
+#ifdef GIT_PERF
+	cl_assert_equal_sz(diff->stat_calls, 13 + 3);
+	cl_assert_equal_sz(diff->oid_calculations, 5);
+	cl_assert_equal_sz(diff->submodule_lookups, 1);
+#endif
+
+	git_diff_free(diff);
+
+	/* now if we do it again, we should see fewer OID calculations */
+
+	basic_diff_status(&diff, &opts);
+#ifdef GIT_PERF
+	cl_assert_equal_sz(diff->stat_calls, 13 + 3);
+	cl_assert_equal_sz(diff->oid_calculations, 0); /* Yay */
+	cl_assert_equal_sz(diff->submodule_lookups, 1);
+#endif
+
+	git_diff_free(diff);
+}