Description of problem:
When I switch away from Firefox to another app by Alt+Tab and then I want to scroll a displayed page without switching back, just hover on Firefox window, it does not scroll but goes in page history back and forth as if I was still holding Alt key.
Version-Release number of selected component (if applicable):
firefox.x86_64 69.0.1-3.fc31
How reproducible:
100%
Steps to Reproduce:
1. Start Firefox while another non-fullscreen app running
2. Create some browsing history
3. Switch to the other window using Alt+Tab keys
4. Hover on Firefox window without switching there and use mouse wheel to scroll
Actual results:
Firefox going in browsing history back and forth
Expected results:
The page should scroll without any url changes
Additional info:
Running a wayland session, I haven't observed such behaviour in any other app (e.g. Chromium works fine), so I expect it is a Firefox problem.