Avoid out-of-bounds access

Task-number: QTBUG-33364
Change-Id: I33d713df5d60a349c48f109a5f76db5fa57573af
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Bump MODULE_VERSION to 5.2.1

Change-Id: I59276a6546747fb7e5e73fba25f199936884a828
Reviewed-by: Matti Paaso <matti.paaso@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>