Affected versions

• Firefox 68.0a1
• Firefox 67.0b9
• Firefox 66.0.3

Affected platforms

• Windows 10 x64
• macOS 10.13
• Ubuntu 18.04 x64

Prerequisites

• Activate a screen-reader (NVDA - Windows, on Ubuntu and mac just activated it from Settings).

Steps to reproduce

1. Open https://reddit.com
2. Click on one of the posts and start to scroll using the keyboard (up and down arrows, Home, End, Page Up and Page Down).
3. Click on the Back buttons and try again.

Expected result

• The scroll is performed without any issues.

Actual result

• Sometimes you can scroll using some of the buttons, some times you can't scroll at all by using any of the buttons from the keyboard.

Regression range

• I don't think this is a regression. I can reproduce the issue on builds from 2010-01-02.

Additional notes

• On mac, the issue is reproducing only when you click on one of the posts and navigate through it.
• This issue is reproducing on other sites too, (like 9gag.com, Facebook while watching a video).

Sounds more likely to be an a11y issue, but we can always put it back in layout if it turns out not to be the case.

The priority flag is not set for this bug.
:Jamie, could you have a look please?

For more information, please visit auto_nag documentation.

Thanks for testing accessibility. This is not a bug. I'm fairly sure that what's happening here is that screen readers often override the arrow keys to navigate the document by line, by character, etc. When exactly this occurs (and how you enable/disable the functionality) depends on the screen reader, but all of the screen readers you mention implement this functionality in one way or another. When this functionality is engaged, the arrow keys should scroll the document eventually, but they scroll according to the screen reader's position in the document, which will be quite different from the inbuilt visual scrolling behaviour usually seen when you use the arrow keys.