Fix constructing a QSharedPointer<const> of a QEnableSharedFromThis type

It should compile, since the std::shared_ptr does.

[ChangeLog][QtCore][QSharedPointer] Fixed a problem that would cause a
compilation error when constructing a QSharedPointer of a const type
when the type derives from QEnableSharedFromThis.

Task-number: QTBUG-49748
Change-Id: I8de47ed6c7be4847b99bffff141c84f5e0b6bea8
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 44 insertions, 6 deletions

diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
index 7741803224..b63485e91e 100644
--- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
+++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
@@ -94,18 +94,18 @@ private slots:
     void creatingQObject();
     void mixTrackingPointerCode();
     void reentrancyWhileDestructing();
+    void map();
+    void hash();
+    void qvariantCast();
+    void sharedFromThis();
 
     void threadStressTest_data();
     void threadStressTest();
-    void map();
-    void hash();
     void validConstructs();
     void invalidConstructs_data();
     void invalidConstructs();
-
-    void qvariantCast();
-    void sharedFromThis();
-
+    // let invalidConstructs be the last test, because it's the slowest;
+    // add new tests above this block
 public slots:
     void cleanup() { safetyCheck(); }
 
@@ -231,6 +231,14 @@ void tst_QSharedPointer::basics()
         QCOMPARE(sizeof(weakref), 2*sizeof(void*));
     }
 
+    {
+        QSharedPointer<const Data> ptr;
+        QWeakPointer<const Data> weakref;
+
+        QCOMPARE(sizeof(ptr), 2*sizeof(void*));
+        QCOMPARE(sizeof(weakref), 2*sizeof(void*));
+    }
+
     QFETCH(bool, isNull);
     Data *aData = 0;
     if (!isNull)
@@ -2171,6 +2179,16 @@ void tst_QSharedPointer::sharedFromThis()
         QVERIFY(const_scp.isNull());
         QCOMPARE(Data::generationCounter, generations + 1);
         QCOMPARE(Data::destructorCounter, destructions);
+
+        QWeakPointer<SomeClass> wcp = sc.sharedFromThis();
+        QVERIFY(wcp.isNull());
+        QCOMPARE(Data::generationCounter, generations + 1);
+        QCOMPARE(Data::destructorCounter, destructions);
+
+        QWeakPointer<const SomeClass> const_wcp = sc.sharedFromThis();
+        QVERIFY(const_wcp.isNull());
+        QCOMPARE(Data::generationCounter, generations + 1);
+        QCOMPARE(Data::destructorCounter, destructions);
     }
 
     QCOMPARE(Data::generationCounter, generations + 1);
@@ -2182,6 +2200,11 @@ void tst_QSharedPointer::sharedFromThis()
         QVERIFY(const_scp.isNull());
         QCOMPARE(Data::generationCounter, generations + 2);
         QCOMPARE(Data::destructorCounter, destructions + 1);
+
+        QWeakPointer<const SomeClass> const_wcp = sc.sharedFromThis();
+        QVERIFY(const_wcp.isNull());
+        QCOMPARE(Data::generationCounter, generations + 2);
+        QCOMPARE(Data::destructorCounter, destructions + 1);
     }
 
     QCOMPARE(Data::generationCounter, generations + 2);
@@ -2373,6 +2396,21 @@ void tst_QSharedPointer::sharedFromThis()
 
     QCOMPARE(Data::generationCounter, generations + 5);
     QCOMPARE(Data::destructorCounter, destructions + 5);
+
+    {
+        QSharedPointer<const SomeClass> scp2(new SomeClass());
+        QVERIFY(!scp2.isNull());
+        QCOMPARE(Data::generationCounter, generations + 6);
+        QCOMPARE(Data::destructorCounter, destructions + 5);
+
+        QWeakPointer<const SomeClass> wcp2(scp2.constCast<SomeClass>());
+        QVERIFY(!wcp2.isNull());
+        QCOMPARE(Data::generationCounter, generations + 6);
+        QCOMPARE(Data::destructorCounter, destructions + 5);
+    }
+
+    QCOMPARE(Data::generationCounter, generations + 6);
+    QCOMPARE(Data::destructorCounter, destructions + 6);
 }
 
 namespace ReentrancyWhileDestructing {