Bugzilla

(In reply to Emilio Cobos Álvarez (:emilio) from comment #5)
> Daniel / others: Do you know what that code is doing? Should it work on replaced elements?

We discussed this on slack, but I forgot to update the bug.

tl;dr: this is for `align-content:baseline` which is indeed specced as inflating the padding -- it adds space between the border and the content-box of a grid item. See https://bugzilla.mozilla.org/show_bug.cgi?id=1256429#c1 and https://drafts.csswg.org/css-align-3/#baseline-align-content for more on this.

`align-content:baseline` is a pretty niche behavior and I'm pretty sure we're still the only browser to implement it (we're alone in passing https://wpt.fyi/results/css/css-grid/alignment/grid-item-mixed-baseline-001.html?label=master&label=experimental for example), so it'd probably fine to turn off this behavior for themed-widgets-that-don't-support-padding, if we have a way to do that.

(In reply to Emilio Cobos Álvarez (:emilio) from comment #5)
> Daniel / others: Do you know what that code is doing? Should it work on replaced elements?

We discussed this on slack, but I forgot to update the bug.

tl;dr: this is for `align-content:baseline` which is indeed specced as inflating the padding -- it adds space between the border and the content-box of a grid item (we only implement it in grid; bug 1480850 is filed on implementing in flexbox). See https://bugzilla.mozilla.org/show_bug.cgi?id=1256429#c1 and https://drafts.csswg.org/css-align-3/#baseline-align-content for more on this.

`align-content:baseline` is a pretty niche behavior and I'm pretty sure we're still the only browser to implement it (we're alone in passing https://wpt.fyi/results/css/css-grid/alignment/grid-item-mixed-baseline-001.html?label=master&label=experimental for example), so it'd probably fine to turn off this behavior for themed-widgets-that-don't-support-padding, if we have a way to do that.