xfree86/modes: Call xf86RotateRedisplay from xf86CrtcRotate

If a new rotate buffer was allocated. This makes sure the new buffer
has valid transformed contents when it starts being displayed.

Reviewed-by: Adam Jackson <ajax@redhat.com>

hw/xfree86/modes/xf86Rotate.c

@@ -485,6 +485,9 @@ xf86CrtcRotate(xf86CrtcPtr crtc)
 
     if (damage)
         xf86CrtcDamageShadow(crtc);
+    else if (crtc->rotatedData && !crtc->rotatedPixmap)
+        /* Make sure the new rotate buffer has valid transformed contents */
+        xf86RotateRedisplay(pScreen);
 
     /* All done */
     return TRUE;