Bug#921046: xserver-xorg-core: Xorg crashes when I run the Easystroke application

["Mark St. John" <mark@markstjohn.net>]

After digging a bit further, I found the following commit from xorg that definitively fixes the issue for me: https://gitlab.freedesktop.org/xorg/xserver/commit/ce393de0efb8626d15f3b97c97916971a6aefebd

I've attached a patch that replicates this fix for X.Org X Server 1.19.6. Please use this patch and disregard the easystroke.diff one that I sent earlier.

Fixing Easystroke crash
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -744,10 +744,13 @@
     drmmode_ptr drmmode = drmmode_crtc->drmmode;
     uint32_t handle = drmmode_crtc->cursor_bo->handle;
     modesettingPtr ms = modesettingPTR(crtc->scrn);
+    CursorPtr cursor = xf86CurrentCursor(crtc->scrn->pScreen);
     int ret = -EINVAL;
 
+    if (cursor == NullCursor)
+        return TRUE;
+
     if (!drmmode_crtc->set_cursor2_failed) {
-        CursorPtr cursor = xf86CurrentCursor(crtc->scrn->pScreen);
 
         ret =
             drmModeSetCursor2(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id,