See: http://css-class.com/test/css/overflow/float-container-margin-overflow.htm In current WebKit, the right float is not allowed to have its left edge extend beyond the left border edge. This is not correct according to the CSS2.1 spec and does not match Firefox.
Created attachment 20179 [details] Remove the clamping code Remove the code that clamps right floats to the left border edge.
I will land this patch with a better test case that doesn't depend on resizing the window.
Comment on attachment 20179 [details] Remove the clamping code r=me because I know you'll add a ChangeLog and test case -- but why not do that before setting the review flag next time?
Because keeping a ChangeLog in my tree for days is a giant pain when I'm doing other work.
I have created a new test case without the need for scrolling. Just one element floated right. Firefox will hide the left edge of the float beyond the left edge of the viewpoint. Safari will show the full width of the float causing a horizontal scrollbar. See: http://css-class.com/test/bug/float-right-left-edge-hidden.htm
Hyatt, are you planning on landing this?
Comment on attachment 20179 [details] Remove the clamping code Let me get a test case and changelog.
Fixed in r36061.