QTBUG-4887 and other exception safety fixes

This change includes a fix for QTBUG-4887 and other exception safety
problems found while testing it.

The QTBUG-4887 fix is to qimage.cpp. QImage doesn't throw exceptions on
failure like a proper class should, instead it tries to fail "nice".
What happens here is that setAlphaChannel would crash on OOM as after
the convertToFormat call, d could be NULL. This new version checks the
result of the conversion before using it.

The other fixes are all cases where exceptions were thrown from
destructors. I added code to the test app to help debug these cases,
and I fixed all the problems I found.

With these changes, tst_exceptionsafety_objects runs and passes on the
Symbian emulator.

Reviewed-by: Shane Kearns

1 files changed, 19 insertions, 0 deletions

diff --git a/tests/auto/exceptionsafety_objects/tst_exceptionsafety_objects.cpp b/tests/auto/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
index 4433c7a..91d1a44 100644
--- a/tests/auto/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
+++ b/tests/auto/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
@@ -43,6 +43,7 @@
 #include <QtTest/QtTest>
 
 #include <stddef.h>
+#include <exception>
 
 QT_USE_NAMESPACE
 
@@ -285,8 +286,26 @@ void tst_ExceptionSafetyObjects::safeMessageHandler(QtMsgType type, const char *
     allocFailer.reactivateAt(currentIndex);
 }
 
+typedef void (*PVF)();
+PVF defaultTerminate;
+void debugTerminate()
+{
+    // you can detect uncaught exceptions with a breakpoint in here
+    (*defaultTerminate)();
+}
+
+PVF defaultUnexpected;
+void debugUnexpected()
+{
+    // you can detect unexpected exceptions with a breakpoint in here
+    (*defaultUnexpected)();
+}
+
 void tst_ExceptionSafetyObjects::initTestCase()
 {
+    // set handlers for bad exception cases, you might want to step in and breakpoint the default handlers too
+    defaultTerminate = std::set_terminate(&debugTerminate);
+    defaultUnexpected = std::set_unexpected(&debugUnexpected);
     testMessageHandler = qInstallMsgHandler(safeMessageHandler);
 
     QVERIFY(AllocFailer::initialize());