Invisible Operators should not add space

[Frédéric Wang (:fredw)]

Created attachment 201047 [details]
testcase

In the attached test case (from the MathML spec), you see that invisible operators add space to the mathematical formulas. However, they should have width=0 and per the Operator dictionary (http://www.w3.org/TR/MathML/appendixc.html) no space around them.

[Frédéric Wang (:fredw)]

A Chromium bug was reported last January:
http://code.google.com/p/chromium/issues/detail?id=169753

[Frédéric Wang (:fredw)]

Created attachment 225243 [details]
Patch

[Frédéric Wang (:fredw)]

Created attachment 225996 [details]
Patch

Just refreshing the patch.

[chris fleizach]

Comment on attachment 225996 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=225996&action=review

is this ready for r?

> Source/WebCore/rendering/mathml/RenderMathMLOperator.h:91
> +    bool isInvisibleOperator() { return 0x2061 <= m_operator && m_operator <= 0x2064; }

this can be const

[Frédéric Wang (:fredw)]

(In reply to comment #4)
> (From update of attachment 225996 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=225996&action=review
> 
> is this ready for r?

I don't think the patch will change much, but this applies on top of the patch of bug 115787 which itself applies on top of bug 124838... Did you find anything about how to make the accessibility test pass after the patch for bug 124838?

[Frédéric Wang (:fredw)]

Created attachment 226402 [details]
Patch + 115787 for testing

[Frédéric Wang (:fredw)]

Created attachment 226411 [details]
Patch

This applies on top of 115787.

[chris fleizach]

Comment on attachment 226411 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=226411&action=review

> Source/WebCore/rendering/mathml/RenderMathMLOperator.cpp:1306
> +            // In some fonts, glyphs for invisible operators have nonzero width. Consequently, we substract that width here to avoid wide gaps.

substract -> subtract

[Frédéric Wang (:fredw)]

Committed r165464: <http://trac.webkit.org/changeset/165464>

[Frédéric Wang (:fredw)]

Interestingly, <p>_&#x2062;_</p> does not produce space on Gecko but it does on WebKit. According to Khaled Hosny, HarfBuzz handles these characters specifically:

https://bugzilla.mozilla.org/show_bug.cgi?id=522393#c43