478092 - when loading page, some images have white horizontal lines through them

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Joel Maher ( :jmaher ) (UTC -8)]

if you browse to www.spreadfirefox.com, you will see an image of some fine young mozilla models wearing firefox shirts.  When this loads, you end up with white horizontal lines.

I have seen this on mac and linux desktop versions of fennec from alpha2->current trunk.  Running on the device, I don't see this (maemo only, had trouble loading on my windows mobile build).

Comment 1

[Dave Townsend [:mossop]]

I see this effect as well in my Tab Sidebar extension, which uses the MozAfterPaint event to draw the browser contents onto a canvas, much like Fennec, so I suspect the rect sent with the event doesn't cover the whole area of the image drawn as it is loading.

Comment 2

[(dormant account)]

I see a white border around stuff drawn with drawWindow, This is especially evident on animated images.

Comment 3

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

I wonder whether this is related to bug 477236? Or perhaps bug 477519...

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Sounds more like 477519. A testcase would be great...

Comment 5

[Dave Townsend [:mossop]]

I'm not entirely sure it is either, I see the white lines in the canvas when they aren't in the browser display. I'm also not sure how I would construct a testcase that includes a slow loading image since that seems to be what triggers this.

Comment 6

[(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!!!

also scroll offset fix in bug 477855 seems to fix the bonus problems introduced in fennec.

Comment 7

[(dormant account)]

Attachment: fixes all of the painting issues i found

this is pretty much the same patch as in bug 477855, except it also deals with animated gif issues(ie mozafterpaint) in addition to viewportHandler fixes. I think this is a more appropriate bug for it.

Comment 8

[(dormant account)]

http://hg.mozilla.org/mobile-browser/rev/f35ab2861209