Bug 116232 – REGRESSION: MathML in an XHTML "a" link element is now underlined

• Component: MathML
• Status: NEW

[Chris W. Johnson]

Created attachment 201965 [details]
MathML embedded in an XHTML "a" link element.

In the current Safari (6.0.4) the following is not a problem, but it is a problem in the current WebKit nightlies:

Embedding MathML markup within an XHTML "a" link element causes every element in the MathML markup to appear with a blue link underline. While logical up to a point, this is not a good practice when dealing with MathML. The most serious problem is that it can change the apparent meaning of elements in the MathML, notably and plus sign with a link underline looks like a completely operator, the "±" sign. Less serious, but worth considering, is that it makes a visual mess of the MathML rendering.

[Alexey Proskuryakov]

Firefox behaves as expected: MathML content is clickable and blue, but not underlined.

[Frédéric Wang (:fredw)]

Gecko has the following rule in the MathML stylesheet:

:-moz-any-link {
  text-decoration: none !important;
}

Probably, the same should be done in Source/WebCore/css/mathml.css (with -webkit instead of -moz).

[Frédéric Wang (:fredw)]

Mmm, even setting text-decoration: none explicitly on the <math> does not seem to remove the underline, so I guess it is done by another mechanism.

BTW, Gecko does not handle this case very well either, it does not underline the text, but gaps are visible:
https://bugzilla.mozilla.org/show_bug.cgi?id=667567

Also, I believe the appropriate way to do links is via the MathML3 href attribute (bug 85733).

[Ahmad Saleem]

I am still able to reproduce this bug using attached test case in Safari Technology Preview 153 and it shows "underline" and Chrome seems to be broken in this case while Firefox seems to render it quite good but the bug mentioned in Comment 03 is still open.

Just wanted to share updated status. Thanks!

[Ahmad Saleem]

If needed, we can try to give another try to amend mathml.css and see if there is any difference?

https://github.com/WebKit/WebKit/blob/main/Source/WebCore/css/mathml.css