Right in the middle of the fade transition, the previous and the next slide are painted each with 50% opacity on top of black background. This means that the black background will be slightly visible, which it shouldn't be. I propose a patch to fix this.


Reproducible: Always

Steps to Reproduce:
1. Open a PDF with blank white pages and fade transitions
2. Start a presentation
3. Switch between the pages

Actual Results:  
The screen goes from white to light gray to white

Expected Results:  
The screen stays white