Fix for dwm crashing following unmapping of systray window that had been moved to another monitor ref. #423

dwm.c

@@ -2516,8 +2516,10 @@ manage(Window w, XWindowAttributes *wa)
 		#endif // CENTER_TRANSIENT_WINDOWS_PATCH | CENTER_TRANSIENT_WINDOWS_BY_PARENT_PATCH | CENTER_PATCH
 	} else {
 		#if SEAMLESS_RESTART_PATCH
-		if (!settings_restored)
+		if (!settings_restored || c->mon == NULL) {
 			c->mon = selmon;
+			settings_restored = 0;
+		}
 		#else
 		c->mon = selmon;
 		#endif // SEAMLESS_RESTART_PATCH

patch/seamless_restart.c

@@ -39,12 +39,12 @@ persistclientstate(Client *c)
 int
 restoreclientstate(Client *c)
 {
-	return getclienttags(c)
-		| getclientfields(c)
-		#if SAVEFLOATS_PATCH
-		| restorewindowfloatposition(c, c->mon ? c->mon : selmon)
-		#endif // SAVEFLOATS_PATCH
-	;
+	int restored = getclientfields(c);
+	getclienttags(c);
+	#if SAVEFLOATS_PATCH
+	restorewindowfloatposition(c, c->mon ? c->mon : selmon);
+	#endif // SAVEFLOATS_PATCH
+	return restored;
 }
 
 void setmonitorfields(Monitor *m)