Unstable v0.19.3.0

Barotrauma/BarotraumaShared/SharedSource/Networking/NetIdUtils.cs

@@ -28,6 +28,19 @@ namespace Barotrauma.Networking
         public static bool IdMoreRecentOrMatches(ushort newId, ushort oldId)
             => !IdMoreRecent(oldId, newId);
 
+        /// <summary>
+        /// Returns some ID that is older than the input ID. There are no guarantees
+        /// regarding its relation to values other than the input.
+        /// </summary>
+        public static ushort GetIdOlderThan(ushort id)
+#if DEBUG
+            // Debug implementation has some RNG to discourage bad assumptions about the return value
+            => unchecked((ushort)(id - 1 - Rand.Int(500, sync: Rand.RandSync.Unsynced)));
+#else
+            // Release implementation favors performance
+            => unchecked((ushort)(id - 1));
+#endif
+
         public static ushort Difference(ushort id1, ushort id2)
         {
             int diff = id2 > id1 ? id2 - id1 : id1 - id2;