540521 - wrong line height on Youtube, when default font is Meiryo

Status: NEW

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

Description

[ICHIMARU Takeshi(a.k.a. Ayakawa)]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.1; ja; rv:1.9.2) Gecko/20100118 Namoroka/3.6 (ayakawa PGU)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a1pre) Gecko/20100117 Minefield/3.7a1pre

When default font is メイリオ(Meiryo), thumbnail title line with japanese lacks the half.
Line with alphabet only not lacks the half.

Reproducible: Always

Steps to Reproduce:
1. Options > Content > Default font > change メイリオ(Meiryo)
2. goto http://www.youtube.com/?gl=JP&hl=ja

Actual Results:  
Line with japanese lacks the half.

Expected Results:  
Show line with japanese fully.

NG:changeset 36457:58359ad70d1b
This regression cause at 2009-12-18 or before...

Comment 1

[ICHIMARU Takeshi(a.k.a. Ayakawa)]

Attachment: sample view Fx3.6rc2 and Trunk

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(In reply to comment #0)
> NG:changeset 36457:58359ad70d1b

What is "NG:" ?

Comment 3

[ICHIMARU Takeshi(a.k.a. Ayakawa)]

sorry. last sentence are:

This regression caused at 2009-12-18(changeset 36457:58359ad70d1b
) or before.
Previous build was not obtained from it.

Comment 4

[ICHIMARU Takeshi(a.k.a. Ayakawa)]

Attachment: sample image Trunk/fx 3.6 rc2 with MS P Gothic and Meiryo

sorry. I miss.
This bug happen Fx 3.5.7 and Fx 3.6rc2 too.

Comment 5

[Jean-Marc Desperrier]

I can confirm (doesn't happen for every single box, but is obvious to spot just on the japanese main page of youtube, Meiryo is a free download for windows XP http://www.microsoft.com/downloads/details.aspx?FamilyID=f7d758d2-46ff-4c55-92f2-69ae834ac928 )

But I can't find any obvious relationship between the changelog in http://hg.mozilla.org/mozilla-central/shortlog/36457 and this bug. 
Maybe bug 533379 fixed by matspal a little earlier ??

Takeshi, do you know the first earlier version that doesn't have the bug ?

I tried to add Meiryo to the font.blacklist.underline_offset black list Masayuki created in bug 417014, but it doesn't seem to fix it the problem.

PS : Meiryo should be the default Japanese font under Windows whenever available, I'll open a bug for that.

Comment 6

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

I don't think that this is our bug. The font size is 12px and the box's height is only 30px. The Meiryo's font metrics at 12px is here:

> tmHeight		18
> tmAscent		13
> tmDescent		5
> tmInternalLeading	6
> tmExternalLeading	0

So, 30px is too short. Basically, web sites shouldn't specify height property for containers of text node.

Comment 7

[Jean-Marc Desperrier]

Actually opposite to what the reporter's attachment 422279 [details] showed, it seems to happen with every version of Firefox.

So there's apparently only left a Tech Evangelism bug to get youtube to not set a fixed height for those boxes.