Input settings window with "double" close X (display glitch) - LiveCD Only

reactos-livecd-0.4.15-dev-5131-g311fcc6-x86-gcc-lin-dbg

(Unable to reproduce with reactos-bootcd-0.4.15-dev-5130-gc1c1279-x86-gcc-lin-dbg)

reactos-livecd-0.4.14-release-97-g1dbf277-x86-gcc-lin-dbg (=> REGRESSION)

BISECT : 

 reactos-livecd-0.4.14-dev-1563-g950124b-x86-gcc-lin-dbg  "Details"
 reactos-livecd-0.4.14-release-97-g1dbf277-x86-gcc-lin-dbg  "Details"
 reactos-livecd-0.4.15-dev-1200-gc3b3fcd-x86-gcc-lin-dbg  "Details"
 /  reactos-livecd-0.4.15-dev-1400-g16e5ce8-x86-gcc-lin-dbg  "Details", sometimes double cross
 reactos-livecd-0.4.15-dev-1500-g8ee88d3-x86-gcc-lin-dbg

• Open Regional Settings

• Open Language > Details

The resulting window has a "double closing X" (top right)

With reactos-livecd-0.4.15-dev-1-gd328584 , reactos-livecd-0.4.15-dev-1000-gb62948e-x86-gcc-lin-dbg symptom is different : "Details" button displayed through child window, but no double X