1530048 - HTML spec says tables should have `border-color:gray`, but we only do that in quirks mode

Status: RESOLVED FIXED

(Core :: Layout: Tables, defect, P3)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1: standards mode

The html spec says that tables should have border-color:gray:

table, td, th { border-color: gray; }

We specify that in our quirks-mode stylesheet, so we only give tables gray borders in quirks mode, but we give them black (i.e. default-color) borders in standards mode.
https://searchfox.org/mozilla-central/rev/dc0adc07db3df9431a0876156f50c65d580010cb/layout/style/res/quirk.css#55-60

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 2: quirks mode

Comment 2

[Daniel Holbert [:dholbert]]

Here are how different browsers render the attached testcases (listing the border colors as "outer/inner", i.e. "table/td"):

                         Firefox 67     Chrome 74 and Safari 12    Edge 18 & IE11
Standards-mode colors:   black/black         gray/black              Black/Black
Quirks-mode colors:      gray/gray           gray/black              Black/Black

So:

• We're the only browser to have a difference based on quirks-mode.
• We're the only browser to ever render gray borders for the td (and th) elements (though it's what the spec says we're supposed to do).
• We have a comment saying our gray color is "for compatibility" (presumably with IE, in the old days), but Edge/IE don't have any special non-default border-coloring behavior for tables anymore (!!)

Maybe we should just get the spec updated? Given the lack of compatibility here and the agreement between Edge and Firefox (and Chrome for td/th), I'm not sure it's useful for HTML to specify a special default "border-color" for table elements that disagrees with the browser ~consensus.

Comment 3

[Daniel Holbert [:dholbert]]

It looks like our quirks-mode rule dates back to https://bugzilla.mozilla.org/show_bug.cgi?id=84307#c20

See also bug 370833 -- the testcases on that bug are interesting (using <table border>) and seem to behave a bit differently...

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: testcase 3: standards-mode, testing border-style:outset as well

Comment 5

[Daniel Holbert [:dholbert]]

Attachment: testcase 3: border-style:solid, vs. inset/outset, vs. inset/outset with explicit border-color:pink (standards-mode)

Comment 6

[Daniel Holbert [:dholbert]]

I filed https://github.com/whatwg/html/issues/4391 on fixing the spec.

Comment 7

[Daniel Holbert [:dholbert]]

And I filed https://bugs.chromium.org/p/chromium/issues/detail?id=935708 and https://bugs.webkit.org/show_bug.cgi?id=195015 on the Chrome/Safari (Blink/WebKit) magic behavior for inset/outset cells' border colors (which is shown in the middle section of testcase 3).

Comment 8

[Daniel Holbert [:dholbert]]

Let's see if we can just remove this quirk.

Try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=c566483359cc82d6949575bfe8d68c2e3da69c33

Comment 9

[Daniel Holbert [:dholbert]]

Attachment: Bug 1530048 part 1: Remove quirks-mode-only UA stylesheet rule that made table borders gray. r?dbaron

This quirk was originally for compatibility with IE, but IE doesn't have this
special behavior anymore (in quirks-mode or in standards-mode).
And Blink/WebKit have yet another set of behaviors, which are also not
quirks-mode-dependent, and vary depending on the part of the table:
https://bugs.chromium.org/p/chromium/issues/detail?id=935708
https://bugs.chromium.org/p/chromium/issues/detail?id=935729

Comment 10

[Daniel Holbert [:dholbert]]

Try run is green, which means we don't have any test coverage for this quirk (I should probably add some before landing).

Comment 11

[Daniel Holbert [:dholbert]]

Attachment: Bug 1530048 part 2: Add test to verify that table, td, and th draw borders using 'currentColor'. r?dbaron

Depends on D21175

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8ff9537201ef
part 1: Remove quirks-mode-only UA stylesheet rule that made table borders gray. r=dbaron
https://hg.mozilla.org/integration/autoland/rev/72127702116c
part 2: Add test to verify that table, td, and th draw borders using 'currentColor'. r=dbaron

Comment 13

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/8ff9537201ef
https://hg.mozilla.org/mozilla-central/rev/72127702116c

Comment 14

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/15748 for changes under testing/web-platform/tests

Comment 15

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Can't merge web-platform-tests PR due to failing upstream checks:
Github PR https://github.com/web-platform-tests/wpt/pull/15748
* Taskcluster (pull_request) (https://tools.taskcluster.net/task-group-inspector/#/f5byuvYzSq-fxen70Fqm8Q)

Comment 16

[Daniel Holbert [:dholbert]]

The "can't merge" reason is bogus; I left a comment in the pull request.