index out of range when using Glow

When using the Glow effect from Qt Quick Graphical Effects in Qt 5.8, i got a runtime error "index out of range" in qvector.h 437.
it appears to be somewhere in qquickopenglshadereffect.cpp.

When removing the Glow block it runs without problems.

see attached a small test program for this.
and an image how it should look like.