Compatibility/Unshippables
From MozillaWiki
This page contains a list of bugfixes, features, or APIs we can't ship (or remove) in Firefox because doing so would break the web for our users.
| Feature Name | Bug(s) | Notes |
|---|---|---|
| -webkit-min-device-pixel-ratio"/"-webkit-max-device-pixel-ratio media query | 1237720 | Enabling this breaks Google docs icons. Last attempt / backout was March 14, 2018 (1444139) |
| TC39 global proposal | 1317422 | Broke deezer, flickr, moment.js, Jira |
| Stop dispatching keypress events for non-printable keys | 968056 | Blocked by bug of Closure framework |
| Start to dispatch keydown and keyup events even during composition | 354358 | Should be fixed at same time with bug 968056 for saving web app developers' cost |
| Hiding all Gecko specific editing UI | 1449564 | Collect actual usage first (1452538) |
| Removing window.controllers | 1010577 | Sites use as a proxy for UA sniffing (possible removal in 1448045) |
| Offline Application Cache | 1237782 | Big players still use this for various high profile sites (e.g. Microsoft), alternative: Service Workers |
| Clear window.name on cross-origin nav | Not certain this is unshippable - safari shipped it years ago, and Chrome is trying | |
| add me | add me | add me |
See also https://html.spec.whatwg.org/#concept-navigator-compatibility-mode and in particular navigator.taintEnabled() and navigator.oscpu.
