RFR: 8208377: Soft hyphens render if not using TextLayout [v3]

[Phil Race]

On Fri, 20 Dec 2024 00:17:54 GMT, Daniel Gredler <dgredler at openjdk.org> wrote:

>> Soft hyphens should never render, regardless of the rendering path used internally.
>> 
>> This PR does not expand the categorization of "complex" characters in `FontUtilities` in order to force the use of `TextLayout` rendering code paths (as was discussed in JBS).
>> 
>> Instead, it takes the existing (limited) format-category checks in `sun.font.CMap` (a TrueType font helper class), expands it to a more general / complete default-ignorable check (`FontUtilities.isDefaultIgnorable(int)`), and then moves these checks out of `CMap` and up a level into the `CharToGlyphMapper` classes themselves.
>> 
>> The Type1 glyph mapper, the TTF glyph mapper, and the macOS glyph mapper have all been updated.
>
> Daniel Gredler has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add more info about test fonts and default-ignorable chars

I am not completely comfortable with this change, as there's a policy change, and I am not as sure as I'd like to be even though it passes all the tests that we normally run.
Also note harfbuzz *happens* to be what we use for layout but that's internal implementation. But I do agree consistency of layout vs non-layout paths is important.
Meaning drawString("XXX") ought to render the same glyphs in the same way as "new TextLayout("XXX").draw(...)  in all cases.
I am approving however, as this is early in 25 and I hope any issues surface early.

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Marked as reviewed by prr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22670#pullrequestreview-2573495758