User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:74.0) Gecko/20100101 Firefox/74.0

Steps to reproduce:

• open the test case attached to bug 1066965:
  https://bugzilla.mozilla.org/attachment.cgi?id=8951336
• click the top contenteditable "text in div (click to edit)"
• press Home or End keys

Actual results:

Nothing

Expected results:

The cursor should jump to the start or end of the line, as is the case when doing this in the bottom contenteditable.

Possibly related to bug 1553852.

I tested this with Firefox 72.0.2 and 74.0 on Windows and Home/End keys work fine there, so this is a Mac-specific issue.

I haven't been able to check on Linux.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

(In reply to Brecht Machie from comment #2)

I tested this with Firefox 72.0.2 and 74.0 on Windows and Home/End keys work fine there, so this is a Mac-specific issue.

I haven't been able to check on Linux.

Works with Firefox 75.0b5 on Ubuntu 18.04.

(In reply to Brecht Machie from comment #2)

this is a Mac-specific issue.

It doesn't work not only in contenteditable in shadow root, the it dones't work in light dom and browser UI (e.g. URL bar, search bar ..), either.
See https://bugzilla.mozilla.org/show_bug.cgi?id=1539376.