QtGraphicalEffects item crashes app when used multiple times in a row with an empty Image source

Using QtGraphicalEffects items (tested ColorOverlay and OpacityMask) within a row with an empty Image item source as source crashed the app with the following stack trace (from Mac OS X):

0 QQuickShaderEffectMaterial::UniformData::operator==(QQuickShaderEffectMaterial::UniformData const&) const QQuickShaderEffectMaterial::UniformData::operator==(QQuickShaderEffectMaterial::UniformData const&) const 0x1001c4bb5
1 QQuickShaderEffectMaterial::compare(QSGMaterial const ) const QQuickShaderEffectMaterial::compare(QSGMaterial const) const 0x1001c4d2b
2 QSGBatchRenderer::Renderer::prepareAlphaBatches() QSGBatchRenderer::Renderer::prepareAlphaBatches() 0x10006fb44
3 QSGBatchRenderer::Renderer::render() QSGBatchRenderer::Renderer::render() 0x100076541
4 QSGRenderer::renderScene(QSGBindable const&) QSGRenderer::renderScene(QSGBindable const&) 0x100085b59
5 QSGRenderer::renderScene(unsigned int) QSGRenderer::renderScene(unsigned int) 0x1000859d4
6 QSGRenderContext::renderNextFrame(QSGRenderer , unsigned int) QSGRenderContext::renderNextFrame(QSGRenderer, unsigned int) 0x10009683c
7 QQuickWindowPrivate::renderSceneGraph(QSize const&) QQuickWindowPrivate::renderSceneGraph(QSize const&) 0x1000dee2a
8 QSGRenderThread::syncAndRender() QSGRenderThread::syncAndRender() 0x1000b327a
9 QSGRenderThread::run() QSGRenderThread::run() 0x1000b4248
10 QThreadPrivate::start(void ) QThreadPrivate::start(void) 0x100a4f8c3
11 _pthread_body _pthread_body 0x7fff94327268
12 _pthread_start _pthread_start 0x7fff943271e5
13 thread_start thread_start 0x7fff9432541d

This use case might occur when an item is dynamically loaded where all the properties are not set yet.

A demo QML file where the crash happens is attached to this report. Please note that the app does not crash when the used Row item contains only one sub item (or only one ColorOverlay item is used). The app does not crash when a valid default Image source property is set.

The crash is reproducible on Mac OS X Beta 5.5 and on Windows Beta 5.5 msvc2012 32bit.

This crash does not happen when used with Qt 5.4.1, so this might be a regression.