From 119a6b51869b7ffba4fa49bc07e78a243fe4a9ba Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Thu, 25 Jan 2024 18:50:19 +0100
Subject: [PATCH] QHttpHeaders: add a missing detach()

Before calling a mutable member function (in this case,
QList::reserve()) on one of the Private members, we need to ensure
exclusive ownership of our external state, otherwise we have a Data
Race, because QList::reserve() is not thread-safe (only re-entrant).

Pick-to: 6.7
Change-Id: I1249de9449865cbf6ab519b0d38b3bf4e743f16d
Reviewed-by: Juha Vuolle <juha.vuolle@qt.io>
---
 src/network/access/qhttpheaders.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/network/access/qhttpheaders.cpp b/src/network/access/qhttpheaders.cpp
index fe6d04687c5..5b32387d919 100644
--- a/src/network/access/qhttpheaders.cpp
+++ b/src/network/access/qhttpheaders.cpp
@@ -1040,6 +1040,7 @@ qsizetype QHttpHeaders::size() const noexcept
 */
 void QHttpHeaders::reserve(qsizetype size)
 {
+    d.detach();
     d->headers.reserve(size);
 }