[Bug 47392] New: Drakensang Online crashes when exiting fullscreen

https://bugs.winehq.org/show_bug.cgi?id=47392

Bug ID: 47392
           Summary: Drakensang Online crashes when exiting fullscreen
           Product: Wine
           Version: 4.10
          Hardware: x86
               URL: https://www.drakensang.com/en
                OS: Linux
            Status: NEW
          Keywords: download
          Severity: normal
          Priority: P2
         Component: directx-d3d
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

It calls IDirect3DDevice9::SetCursorProperties() to change the cursor. As a
result the current cursor (struct wined3d_device.cursor_texture) is destroyed.
Meanwhile, on the CSMT thread, swapchain_gl_present() checks for
wined3d_device.cursor_texture, finds it to exist, then attempts to blit from
the texture to the backbuffer, and crashes trying to access it, because it has
been set to NULL in the meantime.

The fact that this is inherently a race means that probably the crash is
intermittent, or takes different forms. Still, it's clear enough that there is
some form of missing synchronization. I don't know enough about the context to
guess what that should be.