Allow SetWindowLong(... GWL_STYLE) to change visible bit.
diff --git a/windows/win.c b/windows/win.c
index 0e28e2a..68a1e44 100644
--- a/windows/win.c
+++ b/windows/win.c
@@ -2029,8 +2029,8 @@
goto end;
case GWL_STYLE:
style.styleOld = wndPtr->dwStyle;
- newval &= ~(WS_VISIBLE | WS_CHILD); /* Some bits can't be changed this way */
- style.styleNew = newval | (style.styleOld & (WS_VISIBLE | WS_CHILD));
+ newval &= ~(WS_CHILD); /* this bit can't be changed this way */
+ style.styleNew = newval | (style.styleOld & (WS_CHILD));
if (wndPtr->flags & WIN_ISWIN32)
SendMessageA(hwnd,WM_STYLECHANGING,GWL_STYLE,(LPARAM)&style);