From 897a3421f925cb73409d3138d464b8c0ab30d15d Mon Sep 17 00:00:00 2001
From: Ivan Solovev <ivan.solovev@qt.io>
Date: Tue, 11 Aug 2026 14:59:18 +0200
Subject: [PATCH] QBinaryJson::fromBinaryData(): do the comparison in size_t

In Qt 6, the QBA can actually store more than UINT_MAX bytes, so
casting to uint can truncate. Use size_t instead.

Amends the port of Qt container size_type form int to qsizetype
(Qt 6.0).

Task-number: QTBUG-149036
Pick-to: 6.11 6.8 6.5
Change-Id: Ia63cd6576233e74d9cf5e8def9d3e05065a63831
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
(cherry picked from commit 721ed576391211ca53ecdaaecf6dd41df7bc962e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---

diff --git a/src/core5/serialization/qbinaryjson.cpp b/src/core5/serialization/qbinaryjson.cpp
index df8076d..deecb1e 100644
--- a/src/core5/serialization/qbinaryjson.cpp
+++ b/src/core5/serialization/qbinaryjson.cpp
@@ -157,7 +157,7 @@
 */
 QJsonDocument fromBinaryData(const QByteArray &data, DataValidation validation)
 {
-    if (uint(data.size()) < sizeof(QBinaryJsonPrivate::Header) + sizeof(QBinaryJsonPrivate::Base))
+    if (size_t(data.size()) < sizeof(QBinaryJsonPrivate::Header) + sizeof(QBinaryJsonPrivate::Base))
         return QJsonDocument();
 
     QBinaryJsonPrivate::Header h;
@@ -170,7 +170,7 @@
     if (qAddOverflow(uint{sizeof(QBinaryJsonPrivate::Header)}, uint{root.size}, &size))
         return QJsonDocument(); // not representable in Private::ConstData
 
-    if (h.tag != QJsonDocument::BinaryFormatTag || h.version != 1U || size > uint(data.size()))
+    if (h.tag != QJsonDocument::BinaryFormatTag || h.version != 1U || size > size_t(data.size()))
         return QJsonDocument();
 
     std::unique_ptr<QBinaryJsonPrivate::ConstData> d