Fix occasional crashes in canvas getImageData and other places

In some places we allocate custom array objects and in the constructor we call
setArrayType, which will allocate the array's data through the GC. In all of
these cases we need to make sure that the array object itself is protected from
garbage collection, because while in the constructor it may not be yet in the
scope the callee has usually set up.

Change-Id: I96b7af4ae00fd809067e12bacd6563984c5e9240
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/quick/items/context2d/qquickcontext2d.cpp b/src/quick/items/context2d/qquickcontext2d.cpp
index a01ce5db90..f32cf7cbcd 100644
--- a/src/quick/items/context2d/qquickcontext2d.cpp
+++ b/src/quick/items/context2d/qquickcontext2d.cpp
@@ -871,6 +871,9 @@ struct QQuickJSContext2DPixelData : public QV4::Object
         : QV4::Object(engine)
     {
         setVTable(staticVTable());
+        QV4::Scope scope(engine);
+        QV4::ScopedObject protectThis(scope, this);
+        Q_UNUSED(protectThis);
         setArrayType(QV4::ArrayData::Custom);
     }