1645314 - Line breaking opportunities in Japanese are different in firefox and chrome

Status: RESOLVED DUPLICATE of bug 1719535

(Core :: Layout: Text and Fonts, defect)

Description

[Karl Dubost💡 :karlcow]

1. go to https://www.maruzenjunkudo.co.jp/info/20200409-01/

Notice the broken renderin in Firefox Android. Compare to chrome.

Ksenia has created a test case.
https://codepen.io/ksy36/pen/PoPRZxP

We can see that Chrome is breaking at different places. indeed.

On the original site.

<a href="https://honto.jp/store/detail_1570046_14HB320.html" target="_blank" rel="noopener noreferrer">MARUZEN＆ジュンク堂書店 札幌店</a>

For example, in between N (LATIN CAPITAL LETTER N) and ＆ (FULLWIDTH AMPERSAND != AMPERSAND)

for 11:00～19:00 we get a DIGIT ZERO and FULLWIDTH TILDE and DIGIT ONE which chrome is breaking and not firefox.

Comment 1

[Jonathan Kew [:jfkthame]]

In general, it's not guaranteed (or even expected) that browsers will always agree on line breaks; there's no single "correct" behavior, and various heuristics may come into play.

:m_kato might have some opinion on the specific examples here.

Comment 2

[Makoto Kato [:m_kato]]

<a href="https://honto.jp/store/detail_1570046_14HB320.html" target="_blank" rel="noopener noreferrer">MARUZEN＆ジュンク堂書店 札幌店</a>

No, I think that this is another point. This issue is break rule of 10:30～19:00（月～木）. As long as UAX14 rule is NU ÷ East Asia OP, this Gecko rule is different of UAX14.

Comment 3

[Makoto Kato [:m_kato]]

Our current break rule test is considering historical issue of supporting ASCII face mark, so I don't have good decision for all. (At least, I think that this issue is comment #2)...

Comment 4

[Thomas Wisniewski [:twisniewski]]

Setting webcompat P3 priority for now, as we've only seen one such piece of breakage in two years, and doesn't seem to be a major site or major breakage.

Comment 5

[Makoto Kato [:m_kato]]

This is fixed by 1719535. comment #2's behavior is same