666362 - Gray scale text anti-aliasing for 4-5 seconds after scrolling

Status: NEW

(Core :: Graphics, defect)

Description

[Mats Palmgren (inactive)]

Attachment: Testcase #1

Maybe this is the same underlying problem as bug 664966, marking dependent
for now...

STEPS TO REPRODUCE
1. save the attached testcase to a local file
2. copy layout/reftests/fonts/DejaVuSansMono.woff to the same folder
3. load the testcase using a file:// url

(The testcase scrolls the elements automatically in an onload handler)

ACTUAL RESULTS
The ellipsis is initially rendered with grey-scale anti-aliasing pixels,
unlike the nearby text which has light-blue/beige AA pixels.
After 4-5 seconds the AA pixels on the ellipsis changes to the same
colors as for the text.

EXPECTED RESULTS
Same AA colors for the ellipsis as for the text.

PLATFORMS AND BUILDS TESTED
Bug occurs in the latest mozilla-inbound (with bug 647560 and bug 312156 fixed)
on Windows XP.
Bug does NOT occur on Linux.
Bug does NOT occur (on WinXP) with the pref
   gfx.font_rendering.cleartype.use_for_downloadable_fonts
set to false

Comment 1

[Mats Palmgren (inactive)]

Bug also occurs on OSX 10.5.7.  BTW, this bug is the reason the reftest
layout/reftests/text-overflow/bidi-simple-scrolled.html
is disabled on those platforms:
http://hg.mozilla.org/integration/mozilla-inbound/file/e6d61d90c72f/layout/reftests/text-overflow/reftest.list

Comment 2

[Mats Palmgren (inactive)]

It looks like this also occurs on Linux in some cases,
STR in bug 666696 comment 2. (and that doesn't require scrolling)