Merge pull request ppy#28193 from bdach/what-is-discord-doing

Fix discord arbitrarily refusing to work on "too short" strings

osu.Desktop/DiscordRichPresence.cs

@@ -164,8 +164,8 @@ private void updatePresence(bool hideIdentifiableInformation)
  // user activity
  if (activity.Value != null)
  {
- presence.State = truncate(activity.Value.GetStatus(hideIdentifiableInformation));
- presence.Details = truncate(activity.Value.GetDetails(hideIdentifiableInformation) ?? string.Empty);
+ presence.State = clampLength(activity.Value.GetStatus(hideIdentifiableInformation));
+ presence.Details = clampLength(activity.Value.GetDetails(hideIdentifiableInformation) ?? string.Empty);
 
  if (getBeatmapID(activity.Value) is int beatmapId && beatmapId > 0)
  {
@@ -271,8 +271,15 @@ private void onJoin(object sender, JoinMessage args) => Scheduler.AddOnce(() =>
 
  private static readonly int ellipsis_length = Encoding.UTF8.GetByteCount(new[] { '…' });
 
- private static string truncate(string str)
+ private static string clampLength(string str)
  {
+ // For whatever reason, discord decides that strings shorter than 2 characters cannot possibly be valid input, because... reasons?
+ // And yes, that is two *characters*, or *codepoints*, not *bytes* as further down below (as determined by empirical testing).
+ // That seems very questionable, and isn't even documented anywhere. So to *make it* accept such valid input,
+ // just tack on enough of U+200B ZERO WIDTH SPACEs at the end.
+ if (str.Length < 2)
+ return str.PadRight(2, '\u200B');
+
  if (Encoding.UTF8.GetByteCount(str) <= 128)
  return str;