From 0b3c5816c6d6be52918aa51178f03bd760449eb9 Mon Sep 17 00:00:00 2001
From: Ivan Solovev <ivan.solovev@qt.io>
Date: Thu, 13 Jul 2023 16:47:23 +0200
Subject: [PATCH] Explicitly specify the alignment of QUuid::Id128Bytes union

... because otherwise the union can change its alignment based on
the presence of the data128 member.
For example, QtBluetooth explicitly #undef's __SIZEOF_INT128__ in
its removed_api.cpp, which leads to UB without this patch.

Found during API review

Pick-to: 6.6
Change-Id: Ia17122cc9f3d422530cf722ea528591fce7ab7ff
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/plugin/quuid.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/corelib/plugin/quuid.h b/src/corelib/plugin/quuid.h
index 299ce76d7b..ddd24eb678 100644
--- a/src/corelib/plugin/quuid.h
+++ b/src/corelib/plugin/quuid.h
@@ -55,7 +55,7 @@ public:
         Id128           = 3
     };
 
-    union Id128Bytes {
+    union alignas(16) Id128Bytes {
         quint8 data[16];
         quint16 data16[8];
         quint32 data32[4];