Browsers don't hyphenate Mongolian text

[r12a]

This issue has been closed because it was based on a false premise. See #40 (comment)

This issue is applicable to the Traditional Mongolian script.

Hyphenation occurs in writing Mongolian and Todo. U+1806 MONGOLIAN TODO SOFT HYPHEN is used to indicate resumption of a broken word. It functions like U+2010 HYPHEN, except that it appears at the beginning of a line rather than at the end. (Note that lines of Mongolian text are vertical, and progress from left to right.)

More:

• In-word line-breaks

The GAP

Neither Gecko, Blink, and Webkit hyphenate a word when hyphens is set to auto.

When ­ is added to the markup Gecko and Webkit both fail to produce hyphenation. Blink adds a hyphen and breaks the line inside the word, but it applies the hyphen to the bottom of the initial line, rather than to the top of the continuation line.

css-text Describes how to apply hyphenation. It makes no special mention of Mongolian, nor of which character to use and where.

css-text Has a hyphenate-character property which will allow users to specify the character to use for hyphenation, but it doesn't allow control of the location of the character.

Priority

Marked as advanced, since hyphenation is optional.

Tests

You may need to set the font for these tests to work.

Interactive test, Mongolian text is hyphenated when hyphens:auto is set

Interactive test, Mongolian adds a hyphen to the start of the second line when a word is manually hyphenated with SHY

i18n test suite, CSS3 Text, hyphens

General tests for hyphens support. (Results may need updating.)

Action taken

issue Better describe the likely outcomes of hyphenation

Browser bug reports:

Gecko • Blink • Webkit

Outcomes

No changes as yet.

[r12a]

The first comment in this issue contains text that will automatically appear in one or more gap-analysis documents as a subsection with the same title as this issue. Any edits made to that comment will be immediately available in the document. Proposals for changes or discussion of the content can be made in comments below this point.

Relevant gap analysis documents include:
Mongolian

[r12a]

I think this gap report needs to be completely rewritten. My expectation is that Mongolian words should not be split across a line, or need to use the SOFT HYPHEN. However, when compound nouns are separated by TODO SOFT HYPHEN, hyphen should move to the next line (and it has the right line-break property for that). Currently seeking clarification at #30

[asmusf]

My question: I keep hearing that there still are some open issues about the encoding model for (some aspects of) the (traditional) Mongolian script. If that assessment is correct, is it worth spending cycles on this issue? Or have those overarching issues been put to rest in the meantime?

[r12a]

I'm assuming that there is no connection between the handling of hyphens in Hudum and the encoding model changes (which focus on the letters).

[asmusf]

OK, but pending changes would make it difficult to have any implementation that can treat the text "correctly" in its entirety. At least not until they are settled. Just sayin'

[xfq]

issue Better describe the likely outcomes of hyphenation Open.

This issue has been closed now.

[xfq]

Also, what is described in the first comment and what is described in mlreq do not match. One of them needs to be updated.

[r12a]

I'm going to close this issue, and remove the labels that push it into the Mongolian Gap Analysis page, since it is based on the false assumption that TODO SOFT HYPHEN is used for breaking lines within ordinary words.

Hyphenation does NOT normally occur in Mongolian and Todo texts. However, occasionally compound words or names may contain more than one part, separated by a hyphen. In this case the hyphen used should be U+1806 MONGOLIAN TODO SOFT HYPHEN. It is used like U+2010 HYPHEN in English compound nouns, except that it appears at the beginning of a line rather than at the end when a line is wrapped at the hyphen location. (Note that lines of Mongolian text are vertical, and progress from left to right.)

The TODO SOFT HYPHEN behaves as expected in Gecko, Blink, and WebKit. See this test. The behaviour is governed by the Unicode linebreak properties for that character.