Diff xmit of ID player pools

luprex/core/cpp/animqueue.hpp

@@ -168,11 +168,10 @@ public:
 
     // Difference transmission
     //
-    // make_patch will emit zero bytes when there are no differences.
-    // make_patch does not put a 'length' field for the patch as a whole.
-    // apply_patch must receive a patch followed by eof.
+    // When there are no differences, make_patch returns false but
+    // still writes out a valid patch.
     //
-    void make_patch(const AnimQueue &auth, StreamBuffer *sb) const;
+    bool make_patch(const AnimQueue &auth, StreamBuffer *sb) const;
     void apply_patch(StreamBuffer *sb);
 
     // Get the final resting place after all animations are complete.