From e273b6f0387b1154ac26a8067f06c7714cfc5739 Mon Sep 17 00:00:00 2001
From: Maximilian Goldstein <max.goldstein@qt.io>
Date: Wed, 9 Jun 2021 15:02:45 +0200
Subject: [PATCH 15/21] qv4function: Fix crash due to reference being
 invalidated

Function::updateInternalClass creates a reference to a QStringList that is appended to before being used.
This is unsafe and can leads to a segfault if the append() causes a reallocation.

Fixes: QTBUG-94360
Pick-to: 5.15 6.1 6.2
Change-Id: Iac49e8d816cf440ca2b70e133c88314eb8df6b91
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
(cherry picked from commit 7fa28f98824a94396106eadfc028b329985a0cfc)
---
 src/qml/jsruntime/qv4function.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/qml/jsruntime/qv4function.cpp b/src/qml/jsruntime/qv4function.cpp
index cf8a53cf9f..223e64271e 100644
--- a/src/qml/jsruntime/qv4function.cpp
+++ b/src/qml/jsruntime/qv4function.cpp
@@ -136,7 +136,7 @@ void Function::updateInternalClass(ExecutionEngine *engine, const QList<QByteArr
         if (duplicate == -1) {
             parameterNames.append(QString::fromUtf8(param));
         } else {
-            const QString &dup = parameterNames[duplicate];
+            const QString dup = parameterNames[duplicate];
             parameterNames.append(dup);
             parameterNames[duplicate] =
                     QString(0xfffe) + QString::number(duplicate) + dup;
-- 
2.47.1