Wrong render of stacked materials

[Makushimu]

I use material stacking technique a lot for quick material changes. Just change the order should work.
In the latest version from January 21, I noticed a bug.
If we have several materials applied to the same section, leftmost in the stack is rendered, but rightmost in the stack is visible in the viewport.
The one furthest to the right should always be the top one in the viewport as well as when rendering. The order is right to left.