From 543f296e3435732bb441c0f495ba203bda1a013b Mon Sep 17 00:00:00 2001
From: "Ash (Bug Lab)" <ash@openclaw-lab>
Date: Fri, 27 Feb 2026 19:18:06 +0800
Subject: [PATCH] fix(gateway): replace socket.once with socket.on for error
 handling

When a WebSocket client drops off the network, the underlying TCP
socket may emit multiple consecutive 'error' events (e.g., EPIPE,
ECONNRESET) as the server attempts to flush buffered writes.

Using socket.once('error', ...) only handled the first error event.
Subsequent errors had no handler and caused Node.js to throw an
uncaught ERR_UNHANDLED_ERROR, crashing the gateway process.

Using socket.on('error', ...) handles all error events. The close()
callback is already idempotent (guarded by a closed flag at line 173),
so multiple invocations are safe.

Reproduces on v2026.2.26 with any client that drops the TCP connection
while the server has pending writes (heartbeats, in-flight messages).

Fixes #12354
---
 src/gateway/server/ws-connection.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/gateway/server/ws-connection.ts b/src/gateway/server/ws-connection.ts
index c71d27b8c11..b56bdf789cc 100644
--- a/src/gateway/server/ws-connection.ts
+++ b/src/gateway/server/ws-connection.ts
@@ -194,7 +194,7 @@ export function attachGatewayWsConnectionHandler(params: AttachGatewayWsConnecti
       }
     };
 
-    socket.once("error", (err) => {
+    socket.on("error", (err) => {
       logWsControl.warn(`error conn=${connId} remote=${remoteAddr ?? "?"}: ${formatError(err)}`);
       close();
     });