From 22d4bdf00d1a03885dc0171125faddfaef730066 Mon Sep 17 00:00:00 2001
From: Damien Arrachequesne <damien.arrachequesne@gmail.com>
Date: Sun, 26 Jun 2022 08:35:42 +0200
Subject: [PATCH] fix: ignore packet received after disconnection

Related: https://github.com/socketio/socket.io/issues/3095

Backported from https://github.com/socketio/socket.io/commit/494c64e44f645cbd24c645f1186d203789e84af0
---
 lib/socket.js     |  6 +++++-
 test/socket.io.js | 27 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/lib/socket.js b/lib/socket.js
index 4e97eb55dd..33ad8ba4a6 100644
--- a/lib/socket.js
+++ b/lib/socket.js
@@ -525,7 +525,11 @@ Socket.prototype.dispatch = function(event){
       if (err) {
         return self.error(err.data || err.message);
       }
-      emit.apply(self, event);
+      if (self.connected) {
+        emit.apply(self, event);
+      } else {
+        debug("ignore packet received after disconnection");
+      }
     });
   }
   this.run(event, dispatchSocket);
diff --git a/test/socket.io.js b/test/socket.io.js
index 6cc085b798..b75f0c259d 100644
--- a/test/socket.io.js
+++ b/test/socket.io.js
@@ -1838,6 +1838,33 @@ describe('socket.io', function(){
       });
     });
 
+    it("should ignore a packet received after disconnection", (done) => {
+      const srv = http();
+      const sio = io(srv);
+
+      srv.listen(() => {
+        const clientSocket = client(srv);
+
+        const success = () => {
+          clientSocket.close();
+          sio.close();
+          done();
+        };
+
+        sio.on("connection", (socket) => {
+          socket.on("test", () => {
+            done(new Error("should not happen"));
+          });
+          socket.on("disconnect", success);
+        });
+
+        clientSocket.on("connect", () => {
+          clientSocket.emit("test", Buffer.alloc(10));
+          clientSocket.disconnect();
+        });
+      });
+    });
+
     it('should always trigger the callback (if provided) when joining a room', function(done){
       var srv = http();
       var sio = io(srv);