User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20171103003834 Steps to reproduce: I middle click repeatedly and the indicator of scrolling being enabled doesn't toggle reliably. Actual results: So this is similar to https://bugzilla.mozilla.org/show_bug.cgi?id=1099491, but still happens to me in the current developer edition (fully updated as of 2017-11-13). I made a video here: https://www.youtube.com/watch?v=DL47OT2QOb8 Sometimes it just doesn't do anything, at like 10 seconds into the video it starts flickering. Expected results: The scroll indicator/scrolling should toggle reliably.
I don't know how we trigger that functionality. Jim, do you?
I can reproduce this. You trigger it with middle click, on my mouse there's a button integrated into the wheel you press for this.
Is this related to bug 1390247?
(In reply to Jim Mathies [:jimm] from comment #2) > I can reproduce this. You trigger it with middle click, on my mouse there's > a button integrated into the wheel you press for this. Sorry, I should have clarified: I know how to trigger it but are we somehow not sending the middle-click event to Windows to enable this mode?
We handle it internally, not via Windows. The code starts around https://searchfox.org/mozilla-central/rev/550148ab69b2879bfb82ffa698720ede1fa626f2/toolkit/content/browser-content.js#279-285