1409615 - Tab text misaligned when containing East Asian text

Status: RESOLVED DUPLICATE of bug 1432045

(Firefox :: Tabbed Browser, defect, P3)

Description

[Kevin Hsieh]

Attachment: testcase.htm

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Nightly version: 57.0b9 (64-bit)

Steps to reproduce:

Open the attached HTML files in Firefox 57.

Actual results:

Tab text is vertically bottom-aligned (relative to other tabs). This results in misalignment with icons on the tab when there is East Asian text.

Expected results:

Tab text is vertically center-aligned. Reference Chrome and MSIE screenshots.

Comment 1

[Kevin Hsieh]

Attachment: reference.htm

Comment 2

[Kevin Hsieh]

Attachment: screenshots.zip

Comment 3

[Kevin Hsieh]

Correction: This is on 57, not Nightly.

Comment 4

[Jonathan Kew [:jfkthame]]

I don't have a Win7 machine on hand to experiment with this directly (and it doesn't seem to happen on Win10), but it sounds to me like an issue that should be fixed in the front-end, perhaps an adjustment to line-height of the tab title or something like that; it's not clear to me there is a Layout:Text bug here.

The presence of CJK characters in the title presumably results in font fallback choosing a different font from the default for Latin text, and that font may have different ascent/descent metrics, resulting in a different default line-height. Explicitly setting a (sufficiently generous) line-height (perhaps line-height:1.7 or thereabouts) on the tabbrowser-tab class may help to maintain consistent alignment.