STEPS TO REPRODUCE: 1. Load any page in print-preview -- preferably something multi-page, so you have more to scroll. e.g. http://ftp.mozilla.org/pub/mozilla.org/ (2 pages long for me) 2. Scroll up and down. (Either with mousewheel, or uparrow/downarrow, or by clicking the up/down scrollbar buttons, or by dragging the scrollbar) ACTUAL RESULTS: Dark horizontal lines appear across the page, "scrolled into view", from some sizeable percentage of the scrolling operations. (that is, I don't get a dark line for every single "tick" of the scroll operation, but I do get a few dark lines every time I scroll) NOTE: If I *only* scroll by pressing the downarrow key, I get a dark line on every fourth downarrow click. This leads me to believe this is from rounding error. NOTE: If I focus the desktop or a different window, the dark lines instantly go away -- so this appears to be an invalidation bug. Mozilla/5.0 (X11; Linux x86_64; rv:2.0b7pre) Gecko/20100929 Firefox/4.0b7pre
Regression range: 20100902044413 dc2939f2640d 20100903030104 4b879b793eb6 http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=dc2939f2640d&tochange=4b879b793eb6 I'm guessing this is from bug 579276, which had a lot of drawing-related changes, e.g.: >c888cdffd617 Robert O'Callahan — Bug 579276. Part 12: > Clip all drawing to the visible region on the nonretained path. r=cjones
Same as bug 598575?
Ah yes, looks like it.