123266 - PNG corruption on scroll

Status: VERIFIED DUPLICATE of bug 121230

(Core :: Graphics: ImageLib, defect)

Description

[Aaron Kaluszka]

The title PNG on the libpr0n website gets corrupted when the browser window is
scrolled past the image and back onto it.
Build 2002020208

Comment 1

[basic]

seeing this with build 2002020603 win32 trunk on images at
http://www.mozillanews.org/ . I've posted some screenshots at:
http://website.mozdev.org/image1.png
http://website.mozdev.org/image2.png
http://website.mozdev.org/image3.png
http://website.mozdev.org/image4.png
http://website.mozdev.org/image5.png

Comment 2

[Grey Hodge (jX)]

Looks like we have a pattern forming.

*** This bug has been marked as a duplicate of 102401 ***

Comment 3

[Grey Hodge (jX)]

Ok, ok, my bad I missed the previous bug was on an ATI card, which have chronic
problems. Unduping...

Comment 4

[Aaron Kaluszka]

Not sure if this is top100, but it does affect many of the validation buttons on
the bottom of the W3C page.

Comment 5

[Terri Preston]

I see this on win XP build 2002020603, nominating

Comment 6

[basic]

this seems to only affect 32bit PNG images.

Comment 7

[basic]

I take that back it affects other images too, just not all images. I'll attach a
testcase, this might not be an imagelib bug.

Comment 8

[basic]

Attachment: testcase

ok no idea what is going on but at first I thought it might not be an imagelib
bug because I thought I saw part of another image being painted in an image.
Then again, I might have been wrong because the two images are alike. Here is a
testcase.

Comment 9

[basic]

from testing these pages:
http://www.schaik.com/pngsuite/pngsuite_bas_png.html
http://www.schaik.com/pngsuite/pngsuite_int_png.html
http://www.schaik.com/pngsuite/pngsuite_bck_png.html

it seems like it only affect images with alpha.

Comment 10

[Greg Breland]

I saw this problem the other day on Linux at http://www.mozillanews.org on the
top left image, which is a png file with Alpha channels.  However, with build
2002020809 on Linux, this problem seems to be fixed.  I tried every page listed
as having problems and could not recreate this anymore.

Comment 11

[Aaron Kaluszka]

I see it on 2002020908/WinXP

Comment 12

[basic]

bug 124705 has a really cool testcase for this.

Comment 13

[Daniel Steinberger]

*** This bug has been marked as a duplicate of 121230 ***

Comment 14

[Terri Preston]

Verified Duplicate