On my system the mouse cursor disappears if I lock the screen and unlock it again. The GPU, according to lspci, is:
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b)
This is a Gentoo system, that currently uses a snapshot of the xf86-video-intel driver (from 20160407). This bug also appears with the latest git code from today. It does not appear if I downgrade to 2.99.917.
I tried to git-bisect the commit that introduced this bug, but it was impossible, because most of the time the driver simply wouldn't compile.
The screen locker I'm using is light-locker, started by a combination of lxde and lightdm. The way it works is - as far as I know - that the screen gets locked on console 7, a new X instance gets started on console 8 and that shows the passwort prompt. So I assume this happens somehow related to the switching between different X instances. Interestingly the mouse cursor is still there on the password prompt.
Using xorg-server-1.18.2? When it doesn't compile (because X changed its headers?) use git bisect skip.
The compilation errors were of different kind, some of them related to pixman, some seemed to be missing includes (used function fstat without including the appropriate headers).
Possibly related: bug #94677
Yep, seems to be the same as #94677, if I reverse-patch the commit b04767c84deafc44993723add4b1c5163fc11711 the problem disappears.