From 98ca31981977c5a265bb745cc70aafd17384d346 Mon Sep 17 00:00:00 2001
From: Fabian Kosmale <fabian.kosmale@qt.io>
Date: Fri, 28 Feb 2020 15:27:53 +0100
Subject: [PATCH] QMetaType::fromType: support classes with inaccessible dtors

Change-Id: I60a1b2496d48651a8166173b420da37f59d7a395
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/corelib/kernel/qmetatype.h                   |  5 ++++-
 .../corelib/kernel/qmetatype/tst_qmetatype.cpp   | 16 ++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 0bec7ca4c0..1ae0fb45bc 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -2719,7 +2719,10 @@ QMetaTypeInterface QMetaTypeForType<T>::metaType = {
         }
     }),
     /*.dtor=*/ QT_METATYPE_CONSTEXPRLAMDA( -> QMetaTypeInterface::DtorFn {
-        return [](const QMetaTypeInterface *, void *addr) { reinterpret_cast<T *>(addr)->~T(); };
+        if constexpr (std::is_destructible_v<T>)
+            return [](const QMetaTypeInterface *, void *addr) { reinterpret_cast<T *>(addr)->~T(); };
+        else
+            return nullptr;
     }),
     /*.legacyRegisterOp=*/ QT_METATYPE_CONSTEXPRLAMDA( -> QMetaTypeInterface::LegacyRegisterOp {
         if constexpr (QMetaTypeId2<T>::Defined && !QMetaTypeId2<T>::IsBuiltIn) {
diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
index 0d9dfc1c4c..f144aad7e4 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
@@ -126,6 +126,7 @@ private slots:
     void fromType();
     void operatorEq_data();
     void operatorEq();
+    void typesWithInaccessibleDTors();
 };
 
 struct BaseGenericType
@@ -2574,6 +2575,21 @@ void tst_QMetaType::operatorEq()
     QCOMPARE(typeB != typeA, !eq);
 }
 
+class WithPrivateDTor {
+    ~WithPrivateDTor(){};
+};
+
+struct WithDeletedDtor {
+    ~WithDeletedDtor() = delete;
+};
+
+void tst_QMetaType::typesWithInaccessibleDTors()
+{
+    // should compile
+    Q_UNUSED(QMetaType::fromType<WithPrivateDTor>());
+    Q_UNUSED(QMetaType::fromType<WithDeletedDtor>());
+}
+
 // Compile-time test, it should be possible to register function pointer types
 class Undefined;