QSharedPointer: make QT_SHAREDPOINTER_TRACK_POINTERS work with QObjects

If setQObjectShared crashes because a QObject is tracked by two
different QSharedPointers, we lose the debug feature offered by #defining
QT_SHAREDPOINTER_TRACK_POINTERS, as the check done by this define
happens after the setQObjectShared call.

Therefore, move setQObjectShared after the internalSafetyCheckAdd call.

This is actually a noop change in 5.0, as setQObjectShared does nothing.
However it prevents a bug in case the Qt 4 behaviour is brought back
in some later version.

Change-Id: I71340d0f878828354537762d01c46d441efc918c
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index f5a94fe..2cb07ad 100644 (file)
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -387,10 +387,10 @@ public:
 
         // now initialize the data
         new (result.data()) T();
-        result.d->setQObjectShared(result.value, true);
 # ifdef QT_SHAREDPOINTER_TRACK_POINTERS
         internalSafetyCheckAdd(result.d, result.value);
 # endif
+        result.d->setQObjectShared(result.value, true);
         return result;
     }
 
@@ -425,10 +425,10 @@ private:
 # endif
         d = Private::create(ptr, deleter, actualDeleter);
 
-        d->setQObjectShared(ptr, true);
 #ifdef QT_SHAREDPOINTER_TRACK_POINTERS
         internalSafetyCheckAdd(d, ptr);
 #endif
+        d->setQObjectShared(ptr, true);
     }
 
     template <class X>

diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
index 6896b32..f38df1e 100644 (file)
--- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
+++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
@@ -1760,6 +1760,13 @@ void tst_QSharedPointer::invalidConstructs_data()
            "QSharedPointer<Data> ptr1 = QSharedPointer<Data>(aData);\n"
            "QSharedPointer<Data> ptr2 = QSharedPointer<Data>(aData);\n";
 
+    // two QObjects with the same pointer
+    QTest::newRow("same-pointer-to-qobject")
+        << &QTest::QExternalTest::tryRunFail
+        << "QObject *anObj = new QObject;\n"
+           "QSharedPointer<QObject> ptr1 = QSharedPointer<QObject>(anObj);\n"
+           "QSharedPointer<QObject> ptr2 = QSharedPointer<QObject>(anObj);\n";
+
     // re-creation:
     QTest::newRow("re-creation")
         << &QTest::QExternalTest::tryRunFail