Created attachment 257150 [details] Testcase #1 Right padding is missing in the scroll view. STEPS TO REPRODUCE 1. load the attached testcase ACTUAL RESULT In the scroll view there is a yellow box surrounded by 30px padding (white) on all sides except on the right side where it is missing. EXPECTED RESULT In the scroll view there is a yellow box surrounded by 30px padding (white) on all sides. PLATFORMS AND BUILDS TESTED Bug occurs in a SeaMonkey 20070303 nightly build on Linux Bug does not occur in SeaMonkey 2006120701 (pre reflow branch) on Linux. Bug occurs in SeaMonkey 2006120801 (post reflow branch) on Linux.
Our behavior in terms of the right padding actually agrees with Safari. The justification is that the width of the child block is greater than the width of the parent, so it overflows, covering the right padding. Our behavior is arguably wrong in terms of the bottom padding, though. The child block should also overlap the bottom padding. We aren't calulating the computed height of the scrolled frame correctly, at least according to the Safari model. And I think the Safari model is the only one that can really make sense in the long run.
Since this is a regression from the reflow branch, let's try and get this into 1.9.0.x/1.9.1.
The testcase renders the same in Gecko 1.9.x, IE8b2 and Safari 3.1.2. Only Opera 9.5.2 differs and shows a white bottom padding and a twice as wide right padding.
I no longer work for Mozilla, I am deassigning myself from bugs I have no intention of working on as a volunteer.
With the patches in bug 665597, the scroll box accounts for margin/padding on the right and bottom sides (so that yellow/blue boxes have an equal gap on all sides)
The original issue is invalid, and as Eli says in comment 1 we should also overflow the bottom padding. Bug 665597 will fix that, and also the margin case.