QObject: make doSetProperty() take lvalue arg by cref

... not by pointer.

It makes more sense this way, since `lvalue` is always passed (unlike
`rvalue`, which is passed optionally, so needs a nil state), and
removes a potential error state (lvalue == nullptr) that neither the
compiler nor a reader of the code now have to worry about anymore.

As a drive-by, rename the argument so the local alias in the function
can go away, too.

Amends 39cdf431f034121353e51768b4d1fec8b0dd35dc.

Change-Id: I818e4fec30360c5b63b84a0f7e1e1eebdfe2cfcc
Reviewed-by: Ivan Solovev <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>
(cherry picked from commit 4ec8b1096cbe5f888754fcd6de2b549f67a58914)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>

3 files changed, 14 insertions, 5 deletions

diff --git a/src/corelib/compat/removed_api.cpp b/src/corelib/compat/removed_api.cpp
index 5b592bcfc76..4285e39a542 100644
--- a/src/corelib/compat/removed_api.cpp
+++ b/src/corelib/compat/removed_api.cpp
@@ -1465,6 +1465,13 @@ QNoDebug QMessageLogger::noDebug() const noexcept
 
 #include "qmutex.h" // removed, previously-inline API
 
+#include "qobject.h"
+
+bool QObject::doSetProperty(const char *name, const QVariant *lvalue, QVariant *rvalue)
+{
+    return doSetProperty(name, *lvalue, rvalue);
+}
+
 #include "qstring.h" // inlined API
 
 // #include "qotherheader.h"
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 5a6da48d52c..46f2ad7d1c4 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -4371,10 +4371,9 @@ int QObjectPrivate::signalIndex(const char *signalName,
   \overload setProperty
 */
 
-bool QObject::doSetProperty(const char *name, const QVariant *lvalue, QVariant *rvalue)
+bool QObject::doSetProperty(const char *name, const QVariant &value, QVariant *rvalue)
 {
     Q_D(QObject);
-    const auto &value =*lvalue;
     const QMetaObject *meta = metaObject();
     if (!name || !meta)
         return false;
@@ -4413,7 +4412,7 @@ bool QObject::doSetProperty(const char *name, const QVariant *lvalue, QVariant *
         qWarning("%s::setProperty: Property \"%s\" invalid,"
                  " read-only or does not exist", metaObject()->className(), name);
 #endif
-    return rvalue ? p.write(this, std::move(*rvalue)) : p.write(this, *lvalue);
+    return rvalue ? p.write(this, std::move(*rvalue)) : p.write(this, value);
 }
 
 /*!
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h
index 813ccdb6735..8c2cd74281e 100644
--- a/src/corelib/kernel/qobject.h
+++ b/src/corelib/kernel/qobject.h
@@ -387,7 +387,10 @@ protected:
 
 private:
     void doSetObjectName(const QString &name);
+#if QT_CORE_REMOVED_SINCE(6, 10)
     bool doSetProperty(const char *name, const QVariant *lvalue, QVariant *rvalue);
+#endif
+    bool doSetProperty(const char *name, const QVariant &value, QVariant *rvalue);
 
     Q_DISABLE_COPY(QObject)
 
@@ -409,12 +412,12 @@ inline QMetaObject::Connection QObject::connect(const QObject *asender, const ch
 #if QT_CORE_INLINE_IMPL_SINCE(6, 6)
 bool QObject::setProperty(const char *name, const QVariant &value)
 {
-    return doSetProperty(name, &value, nullptr);
+    return doSetProperty(name, value, nullptr);
 }
 #endif // inline since 6.6
 bool QObject::setProperty(const char *name, QVariant &&value)
 {
-    return doSetProperty(name, &value, &value);
+    return doSetProperty(name, value, &value);
 }
 
 template <class T>