fix test `add-deleted-window-p-01` wrongly fail on small window size.
fix test `add-deleted-window-p-01` wrongly fail on small window size.

xyzzy-022/xyzzy,southly/xyzzy.src,NobuoK/xyzzy,xyzzy-022/xyzzy,southly/xyzzy.src,kosh04/xyzzy,xyzzy-022/xyzzy,kosh04/xyzzy,kosh04/xyzzy,southly/xyzzy.src,kosh04/xyzzy,kosh04/xyzzy,NobuoK/xyzzy,NobuoK/xyzzy,NobuoK/xyzzy,NobuoK/xyzzy,xyzzy-022/xyzzy