Debugger: Introduce a tree level above stack frames

This level is meant to take the role of current thread handler
in the long run, allowing per-thread stackviews in each engine.

For now, the additional level holds just a single, invisible
dummy item playing the role of a "current thread".

Change-Id: Ief6131500fc1aa8902f2313038a65840b80b495b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

1 files changed, 2 insertions, 3 deletions

diff --git a/src/plugins/debugger/qml/qmlengine.cpp b/src/plugins/debugger/qml/qmlengine.cpp
index d518d77701..9b745ddf65 100644
--- a/src/plugins/debugger/qml/qmlengine.cpp
+++ b/src/plugins/debugger/qml/qmlengine.cpp
@@ -663,9 +663,8 @@ void QmlEngine::activateFrame(int index)
         return;
 
     stackHandler()->setCurrentIndex(index);
-    auto frameItem = stackHandler()->rootItem()->childAt(index);
-    QTC_ASSERT(frameItem, return);
-    gotoLocation(frameItem->frame);
+    const StackFrame &frame = stackHandler()->frameAt(index);
+    gotoLocation(frame);
 
     d->updateLocals();
 }