Add support for QSharedPointer<cv qualified>::create()

[ChangeLog][QtCore][QSharedPointer] Fixed a problem that made create()
on a type with const qualification fail to compile.

Task-number: QTBUG-68300
Change-Id: I0825ff5b5f6f4c85939ffffd152f3e55e5b9caae
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 15 insertions, 4 deletions

diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index a0e408b94a..bccf8c5740 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -246,7 +246,8 @@ namespace QtSharedPointer {
     struct ExternalRefCountWithContiguousData: public ExternalRefCountData
     {
         typedef ExternalRefCountData Parent;
-        T data;
+        typedef typename std::remove_cv<T>::type NoCVType;
+        NoCVType data;
 
         static void deleter(ExternalRefCountData *self)
         {
@@ -262,7 +263,7 @@ namespace QtSharedPointer {
         }
         static void noDeleter(ExternalRefCountData *) { }
 
-        static inline ExternalRefCountData *create(T **ptr, DestroyerFn destroy)
+        static inline ExternalRefCountData *create(NoCVType **ptr, DestroyerFn destroy)
         {
             ExternalRefCountWithContiguousData *d =
                 static_cast<ExternalRefCountWithContiguousData *>(::operator new(sizeof(ExternalRefCountWithContiguousData)));
@@ -437,10 +438,12 @@ public:
 # endif
         typename Private::DestroyerFn noDestroy = &Private::noDeleter;
         QSharedPointer result(Qt::Uninitialized);
-        result.d = Private::create(&result.value, noDestroy);
+        typename std::remove_cv<T>::type *ptr;
+        result.d = Private::create(&ptr, noDestroy);
 
         // now initialize the data
-        new (result.data()) T(std::forward<Args>(arguments)...);
+        new (ptr) T(std::forward<Args>(arguments)...);
+        result.value = ptr;
         result.d->destroyer = destroy;
         result.d->setQObjectShared(result.value, true);
 # ifdef QT_SHAREDPOINTER_TRACK_POINTERS
diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
index 203d9d8683..ade9c5e754 100644
--- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
+++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
@@ -93,6 +93,7 @@ private slots:
     void lambdaCustomDeleter();
 #endif
     void creating();
+    void creatingCvQualified();
     void creatingVariadic();
     void creatingQObject();
     void mixTrackingPointerCode();
@@ -1771,6 +1772,13 @@ void tst_QSharedPointer::creating()
     safetyCheck();
 }
 
+void tst_QSharedPointer::creatingCvQualified()
+{
+    auto cptr = QSharedPointer<const Data>::create();
+    auto vptr = QSharedPointer<volatile Data>::create();
+    auto cvptr = QSharedPointer<const volatile Data>::create();
+}
+
 void tst_QSharedPointer::creatingVariadic()
 {
     int i = 42;