Show the viewer manually before the end of the scope is reached

viewer/glow-extras/viewer/view.hh

@@ -175,7 +175,8 @@ public:
     }
 
     raii_view_closer(raii_view_closer&& rhs) noexcept : mMustCloseSubview(rhs.mMustCloseSubview) { rhs.isValid = false; }
-    ~raii_view_closer()
+    ~raii_view_closer() { show(); }
+    void show()
     {
         if (!isValid)
             return;
@@ -192,6 +193,7 @@ public:
         {
             on_last_command();
         }
+        isValid = false;
     }
 
     static void convertCurrentSubviewToLayout(layout::settings&& settings)