From 038c1c5978c30675c5f953035a193bc76ca6ca21 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Wed, 3 May 2023 15:10:05 +0200
Subject: [PATCH] QString/QByteArray::op>>: don't assume clear() makes the
 container isNull()

This is something we may want to change at some point, so be explicit
and assign a null container instead of relying on clear().

Add a comment that was present in the QString, but missing in the
QByteArray implementation.

Pick-to: 6.5
Task-number: QTBUG-31283
Task-number: QTBUG-60745
Change-Id: I10d82b8a0c67fff314af526c7b7e0f247c3405fd
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
---
 src/corelib/text/qbytearray.cpp | 4 +++-
 src/corelib/text/qstring.cpp    | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index 1b21c98a2f..22ea718896 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -3222,8 +3222,10 @@ QDataStream &operator>>(QDataStream &in, QByteArray &ba)
     ba.clear();
     quint32 len;
     in >> len;
-    if (len == 0xffffffff)
+    if (len == 0xffffffff) { // null byte-array
+        ba = QByteArray();
         return in;
+    }
 
     const quint32 Step = 1024 * 1024;
     quint32 allocated = 0;
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index b88511087a..87f0cc2c48 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -9245,7 +9245,7 @@ QDataStream &operator>>(QDataStream &in, QString &str)
         quint32 bytes = 0;
         in >> bytes;                                  // read size of string
         if (bytes == 0xffffffff) {                    // null string
-            str.clear();
+            str = QString();
         } else if (bytes > 0) {                       // not empty
             if (bytes & 0x1) {
                 str.clear();