From c9e1eb5075094a837dbe22f757126f1ad1adc763 Mon Sep 17 00:00:00 2001
From: Marco Allegretti <mightymarco4@gmail.com>
Date: Wed, 11 Mar 2026 18:31:35 +0100
Subject: [PATCH] fix(servo-shell): guard create_app_webview against duplicate
 session_id

A broadcast LaunchAck can arrive in addition to any direct response,
causing create_app_webview to be called twice for the same session.
Without the guard the second call silently overwrites the existing
WebView entry without destroying it. Early-return if the session is
already tracked.
---
 crates/weft-servo-shell/src/embedder.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crates/weft-servo-shell/src/embedder.rs b/crates/weft-servo-shell/src/embedder.rs
index dcb7b13..0ea5f2f 100644
--- a/crates/weft-servo-shell/src/embedder.rs
+++ b/crates/weft-servo-shell/src/embedder.rs
@@ -133,6 +133,9 @@ impl App {
     }
 
     fn create_app_webview(&mut self, session_id: u64, app_id: &str) {
+        if self.app_webviews.contains_key(&session_id) {
+            return;
+        }
         let (Some(servo), Some(rc)) = (&self.servo, &self.rendering_context) else {
             return;
         };