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It appears to me that SDL assumes reparenting wm,
I personally use dwm, with SDL 1.2.14 I have problems
(blank or overlapped window spawned) with both dwm 5.6
and 5.7.2 (previously with SDL 1.2.13 only with 5.7.2),
I heard of similar issue with awesome wm. I confirmed same
behaviour also with cwm.