The editor of medium.com is not aware of standardized keypress event behavior of Gecko. So, we need to add medium.com/p/ into the blacklist until they will fix the bug by Medium side.

Medium's editor listens to keypress event to handle Ctrl+Z and Ctrl+Y on Gecko. Therefore, if we don't dispatch keypress events for non-printable keys (by default on Nightly), users cannot use undo/redo in medium.com. This patch makes the editor of medium.com into the blacklist of strict keypress dispatching for avoiding inconvenience of Nightly testers.

Comment on attachment 9013542 [details] Bug 1495627 - Add "medium.com/p/" into dom.keyboardevent.keypress.hack.dispatch_non_printable_keys Olli Pettay [:smaug] (r- if the bug doesn't explain what the change(s) are about.) has approved the revision.

Pushed by masayuki@d-toybox.com: https://hg.mozilla.org/integration/autoland/rev/ef315578d748 Add "medium.com/p/" into dom.keyboardevent.keypress.hack.dispatch_non_printable_keys r=smaug