Fix crash when the return-from-master slide is deleted while in master

Need to check for slide validity before attempting to change to it.

Task-number: QT3DS-1750
Change-Id: I77e93f8f8398169dd9ebf54a8fb281b16407d055
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/Authoring/Studio/Palettes/Slide/SlideView.cpp b/src/Authoring/Studio/Palettes/Slide/SlideView.cpp
index 6f82ef9b..47fb154b 100644
--- a/src/Authoring/Studio/Palettes/Slide/SlideView.cpp
+++ b/src/Authoring/Studio/Palettes/Slide/SlideView.cpp
@@ -93,11 +93,11 @@ void SlideView::setShowMasterSlide(bool show)
         theBridge->GetOrCreateGraphRoot(theRoot); // this will return the master slide
     qt3dsdm::ISlideSystem *theSlideSystem = theDoc->GetStudioSystem()->GetSlideSystem();
     if (m_CurrentModel != m_MasterSlideModel) {
-        if (m_MasterSlideReturnPointers.contains(theNewActiveSlide)) {
-            theNewActiveSlide = m_MasterSlideReturnPointers.value(theNewActiveSlide);
-        } else {
+        qt3dsdm::Qt3DSDMSlideHandle masterSlide = theNewActiveSlide;
+        theNewActiveSlide = m_MasterSlideReturnPointers.value(masterSlide, 0);
+        if (!theSlideSystem->SlideValid(theNewActiveSlide)) {
             theNewActiveSlide = theSlideSystem->GetSlideByIndex(
-                        theNewActiveSlide, 1); // activate the first slide;
+                        masterSlide, 1); // activate the first slide;
         }
     }