User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:74.0) Gecko/20100101 Firefox/74.0

Steps to reproduce:

I think DMABUF was enabled a couple of days ago. It introduced some UI glitches:

1. selecting text with the mouse doesn't draw the selection until mouse up (keyboard selection works fine)
2. the mouse cursor doesn't change until clicking an element

Hi, dmabuf should not be enabled by default as it's used for some specialized tasks only.
Can you check if dmabuf is off by default when you create a new profile?
Thanks.

It's strange. This happens in my old profile even without any add-ons enabled, but if I create a new profile and copy my old prefs.js it works fine.

Is there something I should be looking for? The dmabuf preference is gone, so I'm not sure if it's used or not.

I managed to reproduce this in a new profile + my preferences. Once it happens, there's a "DataSourceSurface of SharedSurfaces does not exist for extId:25769803796" entry in the GPU error log.

If I open a new window, both the mouse selection and cursor work fine until I switch to the previous window and back. After that, they're broken again.

This might be related to bug 1610202. That full-screen toggling issue also occurs after switching windows.

Note: I can't seem to reproduce this any more.