Re: [csswg-drafts] [css-text] How to handle leading ideographic space sequences ? (#4180)

> which of the following results would be the expected one

Result 2 is the expected one.

Here is why:

* Phase 1:
    > A sequence of collapsible spaces at the beginning of a line is removed

    Ideographic spaces are not "collapsible spaces".
    => They do not get removed
    (Nothing else is relevant in "Phase 1")
* Segment Break Transformation Rules
    (Nothing is relevant in that section)
* Phase 2:
   * > as each line is laid out

        wrapping opportunities are allowed after every ideographic space (cf: https://www.unicode.org/reports/tr14/tr14-39.html#BA)
        => We can fit the two U+3000 but no more, and are allowed to wrap after each of them, so they both go on line 1, and XX goes on line 2
    * > A sequence at the end of a line of collapsible spaces (U+0020) and/or other space separators whose white-space value collapses spaces is removed. 

        U+3000 is one of "[other space separators](https://drafts.csswg.org/css-text-3/#white-space-rules)"
        => the two U+3000 at the end of line 1 get removed. That does not change what goes on line 1 or 2, as this happens after splitting into lines. so the XX stay on line 2. However, if there was a span with a background around the U+3000, or a `text-decoration:underline`, the background or underline would not be seen on line 1, since the U+3000 are removed.
        (Nothing else is relevant in "Phase 2")

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Received on Monday, 12 August 2019 12:01:28 UTC