Affected versions

• 75.0, 76.0b4, 77.01a(2020-04-09);

Affected platforms

• macOS 10.15.3, Windows 10, Ubuntu 18.04;

Steps to reproduce

1. Launch Firefox, navigate a few webpages so that the highlights section becmoes populated;
2. Hover over a Highlights tile;
3. Click on the top-right (...) button for the tile;
4. Click on the Delete From History button;
5. Press on the ESC key;
6. Press the TAB key plenty of times - try to open other menus;

Expected result

• modal menu closed at step 5;
• TAB navigation behind the modal should not be possible in the page;
• other menus should not be open;

Actual result

• modal not closed on step 5;
• other menus can be open;
• trying to dismiss another highlight is "doable" but still the modal displayed is in effect dismissing 1st highlight tile;
• :mcoman noticed that that multiple modal menus can be open from this scenario as well;

Regression range

• will check asap;

Additional notes

• attached recording with the main issue.

It doesn't seem to be a regression. Went back as far as 57.0a1 on Windows 10 x64 and the issue is reproducible with every build. Builds prior to that do not have the highlights section displayed.

Thanks, updating fields as well.