Bug 235257 – Two bopomofo tone marks are not moved to the correct place in vertical text with a particular bopomofo font

• Component: Text
• Status: RESOLVED FIXED

[Myles C. Maxfield]

See https://cmex-30.github.io/Bopomofo_on_Web/testpage/index.html

In the last box, these two characters are not placed correctly:

- ˫ U+02EB MODIFIER LETTER YANG DEPARTING TONE MARK
- ˪ U+02EA MODIFIER LETTER YIN DEPARTING TONE MARK

Compare the positioning to Chrome.

[Radar WebKit Bug Importer]

<rdar://problem/87625596>

[Myles C. Maxfield]

Created attachment 449233 [details]
Reduction

[Myles C. Maxfield]

(The attached reduction needs the custom font from https://cmex-30.github.io/Bopomofo_on_Web/testpage/index.html)

[Myles C. Maxfield]

For some reason we're getting two different Font objects in FontCascade::drawGlyphBuffer() which point to the same CTFont

[Myles C. Maxfield]

m_font.glyphDataForCharacter() is reporting different Font objects for those characters. They point to the same CTFont though.

[Myles C. Maxfield]

I see what's happening. The FontCascade::isCJKIdeographOrSymbol() check in FontCascadeFonts::glyphDataForVariant() is returning true for the modifiers but false for the regular characters.

[Myles C. Maxfield]

Created attachment 449287 [details]
Patch

[Darin Adler]

Comment on attachment 449287 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=449287&action=review

> Source/WebCore/ChangeLog:16
> +        No new tests because this requires a custom font to test.

We need to do something about this; maybe make some more custom fonts for the WebKit test suite. That situation is high risk for the project, I think. I’d even like to see this kind of thing tested in WPT.

[Myles C. Maxfield]

Created attachment 450730 [details]
Needs attribution for font creator

[Myles C. Maxfield]

Created attachment 450845 [details]
Patch for committing

[Myles C. Maxfield]

Committed r289101 (246798@trunk): <https://commits.webkit.org/246798@trunk>