I added some traces to understand where the problem was coming from, and I found this: when the problem occurs, the scrollToMousePos() method of the magnifier can be called while the _xDelayed and _yDelayed variables are undefined. This is the case when you enable the magnifier in push mode with focus and caret tracking disabled; calling the startTrackingMouse() method invokes this method very early, even though these variables haven't been defined. We could do it differently, but a simple change in the type check for the variables in question from null to undefined is enough to fix the problem for me (see patch).
** Attachment added: "fix freeze with magnifier in push mode" https://bugs.launchpad.net/gnome-shell/+bug/1991001/+attachment/5865297/+files/check_delayed_undefined -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1991001 Title: Can't move (or see) the mouse cursor during desktop zoom To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1991001/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
