SUMMARY When I click on menus in the menu bar of Firefox Nightly 86.0a1 (2021-1-15) - 88.0a1 (2021-3-6) and 86.0 on Wayland with WebRender enabled in a Fedora 34 KDE Plasma installation with Plasma 5.21.2 and earlier, the menu items under the cursor usually aren't highlighted. Sometimes just the first item in the menu was highlighted. Occasionally multiple items in the menu were highlighted at the same time. The menus shown when right-clicking on a page are also affected by this issue. This problem started with 86.0a1 (2021-1-15). I ran the following to look for the commit involved MOZ_ENABLE_WAYLAND=1 mozregression --good 2021-1-13 --bad 2021-1-18 The end of the process showed 13:17.81 INFO: Narrowed integration regression window from [25680895, 8a9e98e5] (4 builds) to [376c2ff6, 8a9e98e5] (2 builds) (~1 steps left) 13:17.81 INFO: No more integration revisions, bisection finished. 13:17.81 INFO: Last good revision: 376c2ff62872fbf7cc25803f9cbdcd42f8c1fe6c 13:17.81 INFO: First bad revision: 8a9e98e50d031c7a72429a08aad7325f50e34d2e 13:17.81 INFO: Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=376c2ff62872fbf7cc25803f9cbdcd42f8c1fe6c&tochange=8a9e98e50d031c7a72429a08aad7325f50e34d2e The first bad revision was https://hg.mozilla.org/integration/autoland/rev/8a9e98e50d031c7a72429a08aad7325f50e34d2e Bug 1686703 [Wayland] Merge GetWaylandBufferWithSwitch()/GetWaylandBufferRecent() to GetWaylandBuffer(), r=jhorak Depends on D101746 Differential Revision: https://phabricator.services.mozilla.com/D101747 The problem doesn't affect 86.0a1-88.0a1 and 86.0 on X in Plasma on Wayland with the same Firefox settings and system versions. STEPS TO REPRODUCE 1. Boot a Fedora 34 KDE Plasma installation updated to 2021-3-6 with the updates-testing repo enabled 2. Log in to Plasma 5.21.2 on Wayland 3. Install firefox-wayland if it isn't already with sudo dnf install firefox-wayland 4 Start Firefox on Wayland with WebRender compositing enabled 5. Show the menu bar if it isn't already by right-clicking on the tab area and selecting Menu bar 5. Select the Bookmarks menu 6. Move the cursor up and down over the Bookmarks menu 7. Repeat 5-6 for other menus in the menu bar 8. Go to a site such as https://bugzilla.mozilla.org 9. Right-click somewhere on the page 10. Move the cursor up and down the right-click menu OBSERVED RESULT Menu items under the cursor usually aren't highlighted in Firefox 86.0-88.0a1 on Wayland EXPECTED RESULT Menu items under the cursor would be highlighted normally SOFTWARE/OS VERSIONS Linux/KDE Plasma: Fedora 34 (available in About System) KDE Plasma Version: 5.21.2 KDE Frameworks Version: 5.79.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION I reported this problem at https://bugzilla.mozilla.org/show_bug.cgi?id=1693472 Vlad Zahorodnii's comments on that report seemed to indicate that the underlying problem might involve kwin_wayland. I'm unsure if the problem is in Firefox or kwin_wayland.
> Vlad Zahorodnii's comments on that report seemed to indicate that the underlying problem might involve kwin_wayland No, I just indicated that kwin might be doing something that other compositors don't. It still looks like a Firefox bug, not a compositor bug.
s/might be doing/is doing/
(In reply to Vlad Zahorodnii from comment #1) > > Vlad Zahorodnii's comments on that report seemed to indicate that the underlying problem might involve kwin_wayland > > No, I just indicated that kwin might be doing something that other > compositors don't. It still looks like a Firefox bug, not a compositor bug. I didn't mean that your comments indicated that the underlying problem was in kwin_wayland. I just meant that you seemed to say the difference in the way that kwin_wayland handled the issue with the Wayland buffers could be involved in why it shows up in Plasma as opposed to other desktops. I haven't been able to reproduce this problem in GNOME 40 beta. Do you have ideas on how the issue could be addressed? Thanks.
Well, Firefox needs to create a new buffer if the existing one is held by the compositor. I'll mark this bug report as RESOLVED UPSTREAM because it does look like an application bug rather than a compositor bug. If it's false, we can reopen this bug report.
*** This bug has been marked as a duplicate of bug 433011 ***