672161 - When zoomed in, strange artifacts appear on underlined text

Status: RESOLVED DUPLICATE of bug 660189

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

Description

[Stuart Cook]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0.1) Gecko/20100101 Firefox/5.0.1
Build ID: 20110707182747

Steps to reproduce:

Go to http://www.mozilla.com/en-US/firefox/5.0.1/whatsnew/ . Reset zoom, and then zoom once or twice. Look at the "Get answers" link.


Actual results:

Light-grey segments appear on top of the black underline, breaking it up.


Expected results:

The text and its underline should increase in size without introducing any artifacts.

Comment 1

[Stuart Cook]

Attachment: Screenshot of the glitch

Comment 2

[Stuart Cook]

Possibly a duplicate of bug 505243, but it's hard to tell because I can't reproduce the glitch on that bug's test page.

In either case, this does seem to be caused by text-shadow. The glitched parts of the underline align with the letters, and disabling text-shadow in Firebug caused the glitch to disappear.

Comment 3

[Thomas Ahlblom]

Reproduced (but I at least sometimes have to zoom more than just one two steps):
Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.18) Gecko/20110614 Firefox/3.6.18
Mozilla/5.0 (X11; Linux x86_64; rv:5.0) Gecko/20100101 Firefox/5.0
Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20100101 Firefox/6.0
Mozilla/5.0 (X11; Linux x86_64; rv:7.0a2) Gecko/20110717 Firefox/7.0a2
Mozilla/5.0 (X11; Linux x86_64; rv:8.0a1) Gecko/20110717 Firefox/8.0a1

Comment 4

[mjh563]

Yes, it looks as though the white text "shadow" is overlapping the black underline.

Comment 5

[Stuart Cook]

Attachment: Minimal test page

Comment 6

[Stuart Cook]

Attachment: Screenshot of test page at +1 zoom

Comment 7

[Vlad [QA]]

WFM on Mozilla/5.0 (Windows NT 6.1; rv:8.0a1) Gecko/20110802 Firefox/8.0a1
There is no glitch.

Reproducible for me on Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0a1) Gecko/20110802 Firefox/8.0a1

Setting resolution to NEW.

Comment 8

[Mats Palmgren (inactive)]

Attachment: The testcase zoomed up on Linux

Comment 9

[Vitor Menezes]

Isn't this a duplicate of Bug 660189?

Comment 10

[Mats Palmgren (inactive)]

Yes, I agree.