User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/17.0 Firefox/17.0 Build ID: 20120813030532 Steps to reproduce: Swipe left or right on my trackpad to move back or forward through my tab's history. Actual results: On some pages, such as craigslist.org searches, swiping fails completely. I must click on the back button to go back. On other pages (nytimes.com, macrumors.com, in the same history list), I must swipe *twice* before anything happens. Expected results: Swiping should cause the previous or next page to display, depending on swipe direction. This worked reliably until a build from 3 or 4 days ago.
Hmm, this could be a regression of bug 719320.
Okay, this is my fault.
Created attachment 651728 [details] [diff] [review] Patch If there is no scrollable frame for the wheel event, we don't set overflowDelta*. Then, widget understands that the wheel event is consumed. We should always set overflowDelta* when the action is "scroll".
Also seeing this: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/17.0 Firefox/17.0
this seems to be a problem again on the latest nightly 2013-04-11