Test failed `TestBreakIterator::testLao` with icu 70

[Caolán McNamara]

On Sat, 2021-11-13 at 19:56 +0000, oxalica wrote:
> Hello,
> 
> I'm on NixOS and we recently updated a libreoffice dependency `icu`
> to 70.
...
> > /build/libreoffice-
> > 7.2.2.2/i18npool/qa/cppunit/test_breakiterator.cxx:865:TestBreakIte
> > rator::testLao
> > equality assertion failed
> > - Expected: 9
> > - Actual  : 12
> 
> I can confirm that downgrading `icu` back to 69.0 fixes the test 
> failure. But I'm not sure what is this test doing and I cannot read
> Lao.

The test is querying where the words in a Lao sentence are considered
to start and end. Lao, like Thai and a few others, don't typically use
spaces between words which makes figuring that out trickier than for
other languages.

> Does the test need updating, or there it's an issue of the new `icu`
> 70.0?

I have no idea, but its one or the other :-). If you disable/comment-
out the test and carry on, the outcome is that there will be a
difference in where a paragraph breaks when it word wraps from icu69 to
icu70 for Lao text.