I just tested several other browser-versions, and they all behave as-shown the screencast in comment 8: * Chrome 133 dev (current) on Linux * Chrome 55 on Win 10 (roughly the timeframe when we implemented this feature in bug 1261673) * Safari 18.1 on macOS Sequoia So it looks like our implementation in bug 1261673 was overly broad, at least with respect to what's implemented in other browsers (and what was implemented at-the-time in Chromium at least). If we want to add this feature back (for feature parity on sites that opt into it via a `wheel` event listener), we won't want to simply toggle the pref (reverting bug 1741469) because that makes the feature too much of a footgun, as described in bug 1741469. We would need to rework it to have the same constraints as other browsers, around whether there's a `wheel` event-listener, so that hopefully only sites that are interested in this wheel-based-mutation will be opening themselves up to it. I'll leave that to folks on the DOM team if they're interested; my involvement here (in bug 1741469) was just in switching off our preexisting footgunny version of the feature, since as described there, it caused unwanted behavior in all sorts of cases where Chrome/Safari do nothing.
Bug 1939377 Comment 9 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
I just tested several other browser-versions, and they all behave as-shown the screencast in comment 8 (i.e. mousewheel has no effect until I add a 'wheel' event listener): * Chrome 133 dev (current) on Linux * Chrome 55 on Win 10 (roughly the timeframe when we implemented this feature in bug 1261673) * Safari 18.1 on macOS Sequoia So it looks like our implementation in bug 1261673 was overly broad, at least with respect to what's implemented in other browsers (and what was implemented at-the-time in Chromium at least). If we want to add this feature back (for feature parity on sites that opt into it via a `wheel` event listener), we won't want to simply toggle the pref (reverting bug 1741469) because that makes the feature too much of a footgun, as described in bug 1741469. We would need to rework it to have the same constraints as other browsers, around whether there's a `wheel` event-listener, so that hopefully only sites that are interested in this wheel-based-mutation will be opening themselves up to it. I'll leave that to folks on the DOM team if they're interested; my involvement here (in bug 1741469) was just in switching off our preexisting footgunny version of the feature, since as described there, it caused unwanted behavior in all sorts of cases where Chrome/Safari do nothing.