477519 - horizontal white lines randomly appear in image

Status: RESOLVED DUPLICATE of bug 477236

(Core :: Graphics, defect, P1)

Description

[Justin Dolske [:Dolske]]

Attachment: Screenshot of problem

Just noticed this with the linked URL. Horizontal white lines appear at random positions in the image as it loads (slowly, it takes 8-10 seconds). They disappear as soon as the page is scrolled slightly. Reloading the page causes them to come back (reliably, at least for me right now).

Right-click, Properties says "3556px × 1998px (scaled to 624px × 351px)". Also, not using Page Zoom here.

Similar to bug 414975, but they're now white instead of black. :)

Comment 1

[:Gavin Sharp [email: [e-mail]]]

Perhaps related to bug 477236?

Comment 2

[Justin Dolske [:Dolske]]

(Oh, this is on a current 1.9.2 trunk nightly, OS X).

Comment 3

[Jo Hermans]

bug 477728 ?

Comment 4

[(dormant account)]

 animated gifs make this easy to spot, see the red dog gif on
http://www.webdeveloper.com/animations/g.html

Most of these bugs seem to be caused by scaling code used in Fennec, when browsing in zoomLevel==1(tho the dog bug happens at zoom==1), only the following dog bug stands out.

Interestingly opening the gif directly in Fennec avoids the drawing bug

3rd patch in bug 477855 seems to fix the testcase linked in the bug.

Comment 5

[(dormant account)]

I think I found the reason for white lines. If i change the color in drawWindow it becomes obvious.

      ctx.drawWindow(this._browser.contentWindow,
                     rect.left, rect.top,
                     rect.width, rect.height,
                     "red",
                     ctx.DRAWWINDOW_DO_NOT_FLUSH | ctx.DRAWWINDOW_DRAW_CARET);
  
Now every result of drawWindow is drawn with a red border!!!

Comment 6

[(dormant account)]

disgregard 2 of my comments above, they were meant for bug 478092

Comment 7

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Yeah, was going to say -- this bug is not about Fennec, so let's not turn it into one.  Sounds like that's 478092, and that this bug sounds the same as 477236.