1871364 - Version 121 has incorrect width calculations and incorrect automatic line breaks.

Status: RESOLVED DUPLICATE of bug 1870973

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

Description

[webst.net]

Attachment: WS006648.JPG

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0

Steps to reproduce:

Display this sample HTML.

Example:
<style><!--
div{
display:inline-block;
background-color: #cfc;
margin: 5px;
}
--></style>
<div>あいうえおかきくけこ</div><br>
<div>　あいうえおかきくけこ</div><br>
<div>あいうえお　かきくけこ</div><br>
<div>あいうえおかきくけこ　</div><br>
<div>あいうえおかきくけこ</div><br>

Actual results:

If there is a 　 (Japanese full-width space) at the beginning or end of a line, the character width of the space character is not calculated correctly.
As a result, lines may be broken at unintended positions or unintended line widths may be calculated.

Expected results:

The displayed result should be the same as the current display in Firefox versions prior to 120.1 or in other browsers

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Text and Fonts' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[6k64x4ma]

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=0d91ef074019779822e1fa8c7887ba528cafe6af&tochange=3ff9d913d60ad145b0ba96f2bb2a686902421f99

Seems to be a duplicate of bug 1870973.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

:jfkthame, since you are the author of the regressor, bug 1862249, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 4

[Jonathan Kew [:jfkthame]]

This was fixed (by backing out the regressor) in bug 1870973.