Comment 4 for bug 1615871

I was tempted to r+ but it looks like this is an undesirable side effect, so I'd prefer not to rely on that. From the freedesktop bug:

"Weird, not sure why that avoids the problem; maybe there's an off-by-one bug somewhere which causes the window to be incorrectly considered on-screen. I wouldn't recommend relying on that. Also, again I'm not sure that negative coordinates can never be visible."

Also

"Assuming a window is really the only possibility, (why) can't it set the swap interval to 0 via one of the GLX extensions for this, to prevent SwapBuffers operations from getting throttled?"

Can't we do this instead?