3 files changed, 50 insertions, 0 deletions
diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.h b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.h
index 2a0e177be1..fecd5d75c6 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.h
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.h
@@ -31,6 +31,11 @@
 #include "tst_qmetatype_common.h"
 #include "tst_qvariant_common.h"
 
+struct Derived : QObject
+{
+    Q_OBJECT
+};
+
 struct MessageHandlerCustom : public MessageHandler
 {
     MessageHandlerCustom(const int typeId)
@@ -118,6 +123,7 @@ private slots:
     void constRefs();
     void convertCustomType_data();
     void convertCustomType();
+    void convertConstNonConst();
     void compareCustomEqualOnlyType();
     void customDebugStream();
     void unknownType();
diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype2.cpp b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype2.cpp
index 3c097ad0d8..856b56941a 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype2.cpp
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype2.cpp
@@ -278,6 +278,20 @@ void tst_QMetaType::convertCustomType()
     QCOMPARE(v.value<CustomConvertibleType2>().m_foo, testCustom.m_foo);
 }
 
+void tst_QMetaType::convertConstNonConst()
+{
+    auto mtConstObj = QMetaType::fromType<QObject const*>();
+    auto mtObj = QMetaType::fromType<QObject *>();
+    auto mtConstDerived = QMetaType::fromType<Derived const*>();
+    auto mtDerived = QMetaType::fromType<Derived *>();
+
+    QVERIFY(QMetaType::canConvert(mtConstObj, mtObj));
+    QVERIFY(QMetaType::canConvert(mtObj, mtConstObj)); // casting const away is allowed (but can lead to UB)
+    QVERIFY(QMetaType::canConvert(mtConstDerived, mtObj));
+    QVERIFY(QMetaType::canConvert(mtDerived, mtConstObj));
+    QVERIFY(QMetaType::canConvert(mtObj, mtConstDerived));
+}
+
 void tst_QMetaType::compareCustomEqualOnlyType()
 {
     QMetaType type = QMetaType::fromType<CustomEqualsOnlyType>();
diff --git a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
index 23ee85ee46..2883a47852 100644
--- a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
+++ b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
@@ -59,6 +59,7 @@
 #include <QEasingCurve>
 #include <QSequentialIterable>
 #include <QAssociativeIterable>
+#include <QScopeGuard>
 #include "qnumeric.h"
 
 #include <private/qlocale_p.h>
@@ -253,6 +254,7 @@ private slots:
     void convertByteArrayToBool() const;
     void convertByteArrayToBool_data() const;
     void convertIterables() const;
+    void convertConstNonConst() const;
     void toIntFromQString() const;
     void toIntFromDouble() const;
     void setValue();
@@ -3136,6 +3138,34 @@ void tst_QVariant::convertIterables() const
     }
 }
 
+struct Derived : QObject
+{
+    Q_OBJECT
+};
+
+void tst_QVariant::convertConstNonConst() const
+{
+    Derived *derived = new Derived;
+    QObject *obj = derived;
+    QObject const *unrelatedConstObj = new QObject;
+    auto cleanUp = qScopeGuard([&] {
+        delete unrelatedConstObj;
+        delete derived;
+    });
+    QObject const *constObj = obj;
+    Derived const *constDerived = derived;
+    QCOMPARE(QVariant::fromValue(constObj).value<QObject *>(), obj);
+    QCOMPARE(QVariant::fromValue(obj).value<QObject const *>(), constObj);
+
+    QCOMPARE(QVariant::fromValue(constDerived).value<QObject *>(), derived);
+    QCOMPARE(QVariant::fromValue(derived).value<QObject const *>(), derived);
+
+    QObject const *derivedAsConstObject = derived;
+    // up cast and remove const is possible, albeit dangerous
+    QCOMPARE(QVariant::fromValue(derivedAsConstObject).value<Derived *>(), derived);
+    QCOMPARE(QVariant::fromValue(unrelatedConstObj).value<Derived *>(), nullptr);
+}
+
 /*!
   We verify that:
     1. Converting the string "9.9" to int fails. This is the behavior of