Don't do text diff unless content will be used
diff --git a/src/diff_patch.c b/src/diff_patch.c
index 1b4adac..02a45cb 100644
--- a/src/diff_patch.c
+++ b/src/diff_patch.c
@@ -230,6 +230,10 @@ static int diff_patch_generate(git_diff_patch *patch, git_diff_output *output)
if ((patch->flags & GIT_DIFF_PATCH_DIFFED) != 0)
return 0;
+ /* if we are not looking at the hunks and lines, don't do the diff */
+ if (!output->hunk_cb && !output->data_cb)
+ return 0;
+
if ((patch->flags & GIT_DIFF_PATCH_LOADED) == 0 &&
(error = diff_patch_load(patch, output)) < 0)
return error;