15942 - 1px dark lines across page related to background image

Status: VERIFIED FIXED

(Core Graveyard :: GFX, defect, P3)

Description

[Stephen Moehle]

In Mozilla, the page has multiple horizontal lines that extend across the entire
page.  This page displays properly in Communicator 4.7.

Mozilla M10 on RedHat 6.1 i386

Comment 1

[troy]

I don't see this problem with the latest build

Comment 2

[Chris Petersen]

With the Oct 13th Linux Build, I don't see the problem described.

Comment 3

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

In the 10-12 Linux viewer, I see occasionall 1px horizontal lines resulting from
scrolling.  You have to scroll up and down a bit before they appear.  I think
this may be a real (compositor) bug, possibly related to bug 16200.  Reopening,
retitling, and changing component.

Comment 4

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

...and reassigning to owner of Compositor.

Comment 5

[Patrick C. Beard]

*** Bug 16194 has been marked as a duplicate of this bug. ***

Comment 6

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

I'm seeing similar problems on http://www.abc.es/ , even without scrolling.

Comment 7

[Stephen Moehle]

I, also, am still seeing the problem I originally reported.  This is in the Oct
27 build.  No scrolling is involved.  The black lines are there after the
initial display of the page.

Comment 8

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

The common thread between these pages seems to be the background image.  I have
isolated the problem in the ABC page to the background image.  I will attach the
image and a simplified test case that uses it, and a screenshot.

cc:ing pnunn, since this could be related to imagelib.  The image in this case
is 1px tall.

(Could this result from some sort of rounding error in the Compositor?  see
bug 16200)

Is this linux only or is it XP?

Comment 9

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

I am also seeing the black lines in the original page in current builds
(yesterday's) without any scrolling.  Retitling.

Comment 10

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

Attachment: GIF background image used in testcase

Comment 11

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

Attachment: simple testcase demonstrating bug

Comment 12

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

Attachment: screenshot of problem

Comment 13

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

The lines seem to appear in different places after partial repaints (but I think
it's always the same after full repaints).  This can be seen in the lower right
part of the attached screenshot, since a dialog box from gimp appeared over that
area before I took the screenshot.

This makes me strongly suspect a rounding problem.

Comment 14

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

The original reason I cc:ed pnunn was that I thought there was something wrong
with the image, because I thought my image viewer was acting strangely.
However, I discovered it was exhibiting normal behavior (and removed most of my
comments to that effect when I cc:ed pnunn), so the image is probably fine.
pnunn - feel free to remove yourself from the cc: list (nobody ever seems to do
that, but I think it's a sensible thing to do sometimes...).

Comment 15

[pnunn]

no problem dbaron.
I don't mind the cc.
-p

Comment 16

[Stuart Parmenter]

it is a rounding bug.  i have a fix.

Comment 17

[Stuart Parmenter]

it is a rounding bug.  i have a fix.

Comment 18

[Stuart Parmenter]

checked in fix

Comment 19

[Chris Petersen]

Fixed in the Oct 1 Linux build (1999110108).