From bug 35011 comment 69: Looking at http://www.hixie.ch/tests/adhoc/dom/level0/001.html We get onscroll events even when a scroll hasn't happened. For example, drag the vertical scrollbar up beyond its bounds. The event counter keeps incrementing. In IE6, the counter only increments if an actual scroll occurs.

The patch makes sure that there was indeed a change in the scrollbar positionbefore firing the onScroll event. Because of this change onScroll event will not fire if you resize the window and the resize lead to a change in the size of the slider and/or the top position of the slider.

Comment on attachment 99899 [details] [diff] [review] Initial patch Nit of the day: if (presShell && targetFrame && targetContent) presShell->HandleEventWithTarget(&event, targetFrame, targetContent, NS_EVENT_FLAG_INIT, &status); - nsIScrollableView* s = GetScrollableView(mOuter->mPresContext); + s->RemoveScrollPositionListener(this); ScrollbarChanged(mOuter->mPresContext, x*mOnePixel, y*mOnePixel); s->AddScrollPositionListener(this); How about removing the whole line where you're removing the code above, and then also remove the empty line below it. No need to space things out this much IMO. Other than that, this looks great. sr=jst

Comment on attachment 99899 [details] [diff] [review] Initial patch Looks good to me, r=saari

Fix checked in.

verifying build 2003-01-17-04-trunk