Hi @Manta12, thanks for this PR.

I would like to confirm if this change would indeed be compatible with currently supported Firefox versions.
Before merging this, would you please check it on Firefox ESR 52 and 60 (if not already done)?

Ideally this should be a task for automated testing, or a QA team, but I am not sure we have someone in charge.

Thank you again.

Thanks muxator,

Sorry for late my reply.
Yes, I checked ESR, then I confirmed that I can handle to the non-printable key on ESR 52/60. (Tab / Delete / Alt+s ...etc)

Furthermore, this changes will not affect other UAs. (like Chrome/Safari..etc) I tried these browser just in case.

Thanks!

Merged, thanks.

Fixes #3383.

I just noted that this PR (merged in 2be873e) breaks the frontend tests (http://<yourhost>/tests/frontend/), because they were full of special cases that sent keypress when executed in Firefox:

    if(inner$(window)[0].bowser.firefox || inner$(window)[0].bowser.modernIE){ // if it's a mozilla or IE
      var evtType = "keypress";
    }else{
      var evtType = "keydown";
    }

Taking out the special check for Firefox goes back to 10097% success rate for frontend tests in Firefox 61 (when applying only over this change).