1072348 - supplementary-plane ideographs are not handled correctly during justification

Status: RESOLVED FIXED

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

Description

[Jonathan Kew [:jfkthame]]

The IsJustifiableCharacter() helper in nsTextFrame.cpp doesn't handle the (many thousands of) CJK ideograph characters in Plane 2 of Unicode, with the result that they're not treated as justifiable.

Testcase:
  data:text/html;charset=utf-8,<div lang="zh"
    style="font:16px monospace; width:200px; -moz-text-align-last:justify">
    你好<span style="color:red">&%23x210cf;&%23x219c3;</span>你好

Note how the two red (Plane 2) characters remain "stuck together" instead of being spread by justification.

(Other inconsistent spacing in this example is presumably due to bug 1063857, which is a separate issue.)

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Make IsJustifiableCharacter recognize Plane 2 ideographs.

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: Test for justification of text including Plane 2 characters.

Comment 3

[Jonathan Kew [:jfkthame]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/570b7a08a2b7
https://hg.mozilla.org/integration/mozilla-inbound/rev/4a1dd8939824

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/570b7a08a2b7
https://hg.mozilla.org/mozilla-central/rev/4a1dd8939824