Prevent crashes after throwing an exception.

After bc3491c1b85ca36486c9472ecf7ba82f46699e8a, throwing an exception
from a slot will cause the application to crash (segfault). This patch
wraps the offending callFunction call in a try/catch block when
QT_NO_EXCEPTIONS is defined, allowing the appropriate cleanup to occur
and hence preventing the crash.

Task-number: QTBUG-26825
Task-number: QTBUG-27548
Change-Id: Ia3a02398b0308b2216ad17f8f643745bd013fd50
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andy Shaw <andy.shaw@digia.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 9008fb8fb5..5ac32aec53 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -3536,8 +3536,23 @@ void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_sign
                 if (qt_signal_spy_callback_set.slot_begin_callback != 0)
                     qt_signal_spy_callback_set.slot_begin_callback(receiver, c->method(), argv ? argv : empty_argv);
 
+#if defined(QT_NO_EXCEPTIONS)
                 callFunction(receiver, QMetaObject::InvokeMetaMethod, method_relative, argv ? argv : empty_argv);
+#else
+                QT_TRY {
+                    callFunction(receiver, QMetaObject::InvokeMetaMethod, method_relative, argv ? argv : empty_argv);
+                } QT_CATCH(...) {
+                    locker.relock();
+                    if (receiverInSameThread)
+                        QObjectPrivate::resetCurrentSender(receiver, &currentSender, previousSender);
 
+                    --connectionLists->inUse;
+                    Q_ASSERT(connectionLists->inUse >= 0);
+                    if (connectionLists->orphaned && !connectionLists->inUse)
+                        delete connectionLists;
+                    QT_RETHROW;
+                }
+#endif
                 if (qt_signal_spy_callback_set.slot_end_callback != 0)
                     qt_signal_spy_callback_set.slot_end_callback(receiver, c->method());
                 locker.relock();