Don't crash in debugger if QScriptEngine is deleted

Task-number: QTBUG-21548

Change-Id: I925a920c8685cf4cf40c7ad03c2d519e2f2121fb
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/src/scripttools/debugging/qscriptdebuggerbackend.cpp b/src/scripttools/debugging/qscriptdebuggerbackend.cpp
index adc1410..63dcf75 100644
--- a/src/scripttools/debugging/qscriptdebuggerbackend.cpp
+++ b/src/scripttools/debugging/qscriptdebuggerbackend.cpp
@@ -154,6 +154,7 @@ void QScriptDebuggerBackendPrivate::postEvent(QEvent *e)
 {
     if (!eventReceiver) {
         eventReceiver = new QScriptDebuggerBackendEventReceiver(this);
+        Q_ASSERT(agent != 0);
         eventReceiver->moveToThread(agent->engine()->thread());
     }
     QCoreApplication::postEvent(eventReceiver, e);
diff --git a/src/scripttools/debugging/qscriptenginedebuggerfrontend.cpp b/src/scripttools/debugging/qscriptenginedebuggerfrontend.cpp
index 8b08e4c..d1b881c 100644
--- a/src/scripttools/debugging/qscriptenginedebuggerfrontend.cpp
+++ b/src/scripttools/debugging/qscriptenginedebuggerfrontend.cpp
@@ -201,7 +201,8 @@ QScriptEngineDebuggerBackend::~QScriptEngineDebuggerBackend()
 void QScriptEngineDebuggerBackend::processCommand(int id, const QScriptDebuggerCommand &command)
 {
     Q_D(QScriptEngineDebuggerBackend);
-    d->postEvent(new QScriptDebuggerCommandEvent(id, command));
+    if (d->agent)
+        d->postEvent(new QScriptDebuggerCommandEvent(id, command));
 }
 
 /*!