From bf7992f90458b991d572366cf49cd10a64e0eb7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A0=20Arrufat?= <adria.arrufat@gmail.com>
Date: Mon, 8 Jun 2026 10:05:25 +0200
Subject: [PATCH] browser: clear session slot when Session.init fails

newSession set self.session to undefined, but left it non-null if
Session.init failed. closeSession() then ran deinit() on garbage:

- double-released the arena
- read undefined fields on the never-assigned path

Add an errdefer to null the slot on failure.
---
 src/browser/Browser.zig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/browser/Browser.zig b/src/browser/Browser.zig
index 1c6177ee..c52ddadb 100644
--- a/src/browser/Browser.zig
+++ b/src/browser/Browser.zig
@@ -109,6 +109,7 @@ pub fn deinit(self: *Browser) void {
 pub fn newSession(self: *Browser, notification: *Notification) !*Session {
     self.closeSession();
     self.session = @as(Session, undefined);
+    errdefer self.session = null;
     const session = &self.session.?;
     try Session.init(session, self, notification);
     return session;