Bug 837211 added support for "-webkit-appearance" as an alias of "-moz-appearance" (and various other -webkit aliases). But, we later realized that caused visual regressions (bug 1248975 in particular) since our -moz-appearance implementation doesn't work quite like -webkit-appearance (e.g. bug 605985). So we backed out that aliasing in bug 1249134. So currently we have no "-webkit-appearance" support in any shipping builds. Therefore: I'm filing this bug to cover reimplementing a "-webkit-appearance" --> "-moz-appearance" mapping, once we've addressed bug 605985 (and any other incompatibilities we're aware of). (with the goal of improved web compatibility) The patch here will basically consist of backing out bug 1249134. (i.e. backing out the alias-removal)

Thanks for filing the bug, Daniel! Please don't forget to set the dev-doc-needed flag accordingly! Sebastian

See also bug 1333482 for implementing 'appearance' matching the css-ui spec. We should probably fix that bug first, before deciding on what to do about the -webkit- alias.

This was fixed in bug 1333482, although as an alias for 'appearance' not '-moz-appearance'. (the plan is to disable -moz-appearance in a future release: bug 1351745)

Additionally to the mentionings at https://developer.mozilla.org/en-US/docs/Web/CSS/appearance and https://developer.mozilla.org/en-US/Firefox/Releases/54#CSS, I've added compatibility information for this to https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-appearance. Sebastian