Added a fix for X11 / Cinnamon window popups and maximize button not visible.

ptlinux/native/gamescope-keep-nested-windows-visible.patch

@@ -0,0 +1,34 @@
+From: PT Linux Launcher maintainers
+Subject: Keep the nested game window visible during its login transition
+
+PristonTale replaces its startup presentation while entering the login screen
+and asks the nested X11 window manager to mark the game window iconic. Gamescope
+3.16.20 acknowledges that request by publishing IconicState even though the
+surface stays mapped. Wine then hides or resizes the client, which also changes
+the outer Gamescope presentation.
+
+When the launcher opts in through PTLINUX_GAMESCOPE_KEEP_WINDOWS_VISIBLE, keep
+the nested client in NormalState. This is scoped to the launcher environment;
+Gamescope retains its upstream behavior for every other invocation. Desktop
+minimize and focus operate on the outer Wayland window and remain unaffected.
+
+--- a/src/steamcompmgr.cpp
++++ b/src/steamcompmgr.cpp
+@@ -5361,8 +5361,17 @@ static void
+ handle_wm_change_state(xwayland_ctx_t *ctx, steamcompmgr_win_t *w, XClientMessageEvent *ev)
+ {
+ 	long state = ev->data.l[0];
++	static const bool bKeepNestedWindowsVisible = env_to_bool(
++		getenv( "PTLINUX_GAMESCOPE_KEEP_WINDOWS_VISIBLE" ) );
+ 
+ 	if (state == ICCCM_ICONIC_STATE) {
++		if ( bKeepNestedWindowsVisible )
++		{
++			xwm_log.debugf("Ignoring WM_CHANGE_STATE to ICONIC for window 0x%lx", w->xwayland().id);
++			set_wm_state( ctx, w->xwayland().id, ICCCM_NORMAL_STATE );
++			return;
++		}
++
+ 		xwm_log.debugf("Faking WM_CHANGE_STATE to ICONIC for window 0x%lx", w->xwayland().id);
+ 		set_wm_state( ctx, w->xwayland().id, ICCCM_ICONIC_STATE );
+ 	} else {