If a shortcut is set by Firefox, we prevent setting it for an extension, something similar should happen for shortcuts that are already set by an extension.

STR

1. Assign a shortcut to something (like Ctrl+Alt+S)
2. Try to assign another shortcut to the same thing (Ctrl+Alt+S)

Expected results: An error is shown, stating that this shortcut is already defined (possibly including at least one extension name that already defines it)

Actual results: The shortcut is set, but it may or may not execute the related command

@mark, Can I work on this, I have an idea how to get started?

Prevent assigning a shortcut that is already assigned

Pushed by nerli@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/a9aed50dd3eb
Prevent assigning a shortcut that is already assigned r=mstriemer,aswan,flod

https://hg.mozilla.org/mozilla-central/rev/a9aed50dd3eb

Thanks for solving this! Much appreciated.

This issue is verified as fixed on Firefox 68.0a1 (20190404215521) under Win 7 64-bit and Mac OS X 10.14.1.

Please see the attached video.

Is this bug a duplicate of Bug1520123?

They look like dupes, but I think we can keep it. We had identified two things we should do: notify users of duplicates and prevent more duplicates from being created. This bug solves the second case, so I've updated the other bug to solve the first case.