Re: [csswg-drafts] [css-ui] 'auto' as the initial value for the 'appearance' property isn't web-compatible

FYI, we intend to [implement](https://bugzilla.mozilla.org/show_bug.cgi?id=1368555) `-webkit-appearance` with support for **all** values that Chrome supports.  Sadly, that seems to be what is required to be web-compatible. I don't think we're particularly interested in implementing an unprefixed `appearance` property at this point. It would bring zero benefits with a lot web-compat risk. (If Chrome implements and ships that first, then we can reconsider.)  As for standardization, I think it would probably be more useful to add `-webkit-appearance` to the [compat spec](https://compat.spec.whatwg.org/).

> However, would it still be web incompatible if you did not alias the two?

Right, we didn't try that.  Assuming you cascade it separately and that `appearance: none` trumps the prefixed property(ies), then you get problems like:
```css
input {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}
input[type="checkbox"] {
  -webkit-appearance: checkbox;
  /* oops forgot to add the other properties here */
}
```
where the used value will be `none`. I'm also worried about about stray `appearance: none` that web developers added at some point and then forgot about. etc. Personally, I doubt an unprefixed  `appearance`  can be web-compatible in any form. (Sorry, I don't mean to discourage you.)

Anyway, `auto` must of course be the default for `appearance` if it's a separate property that trumps the other ones, so I withdraw my original request. 

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Received on Wednesday, 7 June 2017 13:06:51 UTC