put labeled responses in source buffer

Author: topboy

src/libs/state.js

@@ -579,13 +579,22 @@ function createNewState() {
                 });
             },
 
-            addMessage(buffer, message) {
+            addMessage(b, message) {
                 // Some messages try to be added after a network has been removed, meaning no buffer
                 // will be available
+                let buffer = b;
                 if (!buffer || !buffer.getNetwork()) {
                     return;
                 }
-
+                const label = message.tags.label;
+                if (label !== undefined) {
+                    this.labelBuffer ??= {};
+                    if (!this.labelBuffer[label]) {
+                        this.labelBuffer[label] = buffer;
+                    } else {
+                        buffer = this.labelBuffer[label];
+                    }
+                }
                 let user = this.getUser(buffer.networkid, message.nick);
                 let bufferMessage = new Message(message, user);
                 if (user && user.ignore) {