QPointer: add a test for const QPointer<X>

People use this, so make sure there's a test for it.

I don't expect this test to fail, but static and
dynamic checkers should be presented with this
use-case, so they have a chance of warning, because
certain implementation strategies of QPointer may
make this code undefined.

Change-Id: I334bd73204ba4e186c4098fc6b7188917407e020
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/auto/corelib/kernel/qpointer/tst_qpointer.cpp b/tests/auto/corelib/kernel/qpointer/tst_qpointer.cpp
index d7cce4ada4..f3f485297a 100644
--- a/tests/auto/corelib/kernel/qpointer/tst_qpointer.cpp
+++ b/tests/auto/corelib/kernel/qpointer/tst_qpointer.cpp
@@ -59,6 +59,7 @@ private slots:
 
     void qvariantCast();
     void constPointer();
+    void constQPointer();
 };
 
 void tst_QPointer::constructors()
@@ -402,6 +403,21 @@ void tst_QPointer::constPointer()
     delete fp.data();
 }
 
+void tst_QPointer::constQPointer()
+{
+    // Check that const QPointers work. It's a bit weird to mark a pointer
+    // const if its value can change, but the shallow-const principle in C/C++
+    // allows this, and people use it, so document it with a test.
+    //
+    // It's unlikely that this test will fail in and out of itself, but it
+    // presents the use-case to static and dynamic checkers that can raise
+    // a warning (hopefully) should this become an issue.
+    QObject *o = new QObject(this);
+    const QPointer<QObject> p = o;
+    delete o;
+    QVERIFY(!p);
+}
+
 
 QTEST_MAIN(tst_QPointer)
 #include "tst_qpointer.moc"