1043706 - Error in parsing value for display related to ruby in ua.css

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

When booting up b2g I see a number of "Error in parsing value for 'display'.  Declaration dropped" warnings from ua.css with rules that are display: ruby-something.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

In the past we've found ways to comment out or #ifdef out stuff like this, though it's a pain.  I wonder if we should make presence of pref'd-out properties in the UA style sheet not be errors, given that we've run into this problem enough.

Comment 2

[Daniel Holbert [:dholbert]]

(The chunk of ua.css in question was added in bug 1021952 part 2, FWIW.)

I think we can work around this by wrapping this chunk of ua.cs in an appropriate @supports condition.

e.g. "@supports (display:ruby) { ... }"

(I proposed doing this for a similar flexbox issue a while back, in bug 798592, but at that point it wasn't feasible, because (1) @supports wasn't enabled in release builds yet, and (2) we'd still spam the warnings despite the @supports guard (bug 807336). Fortunately, neither of those should be a problem anymore.)

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Ah, indeed, that's a perfect solution.

Comment 4

[sgbowen]

Attachment: ua-css-bug.patch

Here's the fix dholbert suggested. khuey: can you verify that this makes the error messages go away on b2g? They don't show up on desktop in any case.

Comment 5

[Daniel Holbert [:dholbert]]

Comment on attachment 8462882 [details] [diff] [review]
ua-css-bug.patch

commit-message nit:
>Bug 1043706 - Avoid spamming ruby display errors in b2g. r=dholbert

Per our "describe-the-change" philosophy of commit messages, the commit message should be more like:

Bug 1043706 - Wrap ruby-specific rules in ua.css in a "@supports" clause (to avoid spamming parse errors when ruby is disabled). r=dholbert

r=me with an updated commit message along those lines.

Comment 6

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #5)
> Per our "describe-the-change" philosophy of commit messages

(reference: https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Committing_Rules_and_Responsibilities#Checkin_comment )

Comment 7

[sgbowen]

Attachment: ua-css-bug.patch v2

Indeed, that wasn't a great commit message. Thanks for pointing that out.

Comment 8

[Daniel Holbert [:dholbert]]

Comment on attachment 8462890 [details] [diff] [review]
ua-css-bug.patch v2

Looks good - thanks!

Comment 9

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/fc4786cdbbb8

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/fc4786cdbbb8

Comment 11

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Haven't seen this since.