bug#52067: 29.0.50; string-glyph-split halts on certain emoji strings

[Lars Ingebrigtsen]

Paul Maragakis <paul.maragakis@icloud.com> writes:

> The logic in string-glyph-split expects the first two elements in the result
> from find-composition-internal to give the start and end of a multibyte 
> grapheme
> and return nil when there is a regular character at position POS.  However, 
> this 
> isn't always the case.

Yup.  

Paul Maragakis <paul.maragakis@icloud.com> writes:

> The following code fixes this bug, though there might be better ways
> to fix it for someone who understands the domain.

Thanks.  `find-composition' takes a the LIMIT parameter, and that'll
make it avoid searching back into the bit of the string that we've
already handled.  So I did that instead in Emacs 29.

-- 
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   bloggy blog: http://lars.ingebrigtsen.no