458863 - [@font-face] positioning of text with downloaded fonts differs from system fonts

Status: RESOLVED FIXED

(Core :: Graphics, defect, P3)

Description

[John Daggett (:jtd)]

Attachment: testcase, using downloadable font version of Ahem

When the same font is used both as a locally available font and as a downloadable font, the positioning of text varies.

Steps:

1. Download the testcases into layout/reftests/fonts
     - or -
   Copy the testcases to a folder and put a copy of Ahem in that folder

2. Copy Ahem.ttf into a folder within ~/Library/Fonts

3. Restart trunk build

4. In two tabs, load the two attached testcases

Result: the positioning of the red rectangle varies slightly

Comment 1

[John Daggett (:jtd)]

Attachment: testcase, using local version of Ahem

Comment 2

[philippe (part-time)]

Attachment: alternative test case (with Ahem)

Side by side: left: using @font-face; right using the font installed on the system - the 2 blocks should be identical.
This testcase uses a data url for the font (need to set gfx.downloadable_fonts.enforce_same_site_origin to false)

Also available with downloadable font from
http://dev.l-c-n.com/css3/font-face/baseline-test2.html

-----
The odd thing I've noticed: if the downloaded font is used more than once, in separate block level elements, then it displays correctly:
http://dev.l-c-n.com/css3/font-face/baseline-test2b.html

Comment 3

[Bill Gianopoulos [:WG9s]]

(In reply to comment #2)
> Created an attachment (id=342062) [details]
> alternative test case (with Ahem)

The patch attached to bug 467084 makes this testcase pass.

Comment 4

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

Yeah, the patch there should fix this; taking bug.

Comment 5

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

Fixed on mozilla-central by bug 467084.  That still needs to land on 1.9.1, though.