Abstract checkpoint saving to its own function

This also makes the save failed textbox not appear in special modes,
and allows custom levels to quicksave from checkpoints as well.

desktop_version/src/Entity.cpp

@@ -2750,17 +2750,7 @@ bool entityclass::updateentities( int i )
                 }
                 entities[i].state = 0;
 
-                if (game.checkpoint_saving)
+                game.checkpoint_save();
-                {
-                    bool success = game.savequick();
-                    game.gamesaved = success;
-                    game.gamesavefailed = !success;
-
-                    if (game.gamesavefailed) {
-                        game.show_save_fail();
-                        graphics.textboxapplyposition();
-                    }
-                }
             }
             break;
         case 9: //Gravity Lines

desktop_version/src/Game.cpp

@@ -845,6 +845,22 @@ void Game::show_save_fail(void)
     graphics.textboxtranslate(TEXTTRANSLATE_FUNCTION, save_textbox_fail);
 }
 
+void Game::checkpoint_save(void)
+{
+    if (checkpoint_saving && !inspecial())
+    {
+        bool success = map.custommode ? customsavequick(cl.ListOfMetaData[playcustomlevel].filename) : savequick();
+        gamesaved = success;
+        gamesavefailed = !success;
+
+        if (gamesavefailed)
+        {
+            show_save_fail();
+            graphics.textboxapplyposition();
+        }
+    }
+}
+
 void Game::savetele_textbox(void)
 {
     if (inspecial() || map.custommode)

desktop_version/src/Game.h

@@ -226,6 +226,7 @@ public:
     void remaining_textbox(void);
     void actionprompt_textbox(void);
     void show_save_fail(void);
+    void checkpoint_save(void);
     void savetele_textbox(void);
 
     void setstate(int gamestate);

desktop_version/src/Script.cpp

@@ -1207,17 +1207,7 @@ void scriptclass::run(void)
                     game.savedir = obj.entities[i].dir;
                 }
 
-                if (game.checkpoint_saving)
+                game.checkpoint_save();
-                {
-                    bool success = game.savequick();
-                    game.gamesaved = success;
-                    game.gamesavefailed = !success;
-
-                    if (game.gamesavefailed) {
-                        game.show_save_fail();
-                        graphics.textboxapplyposition();
-                    }
-                }
             }
             else if (words[0] == "gamestate")
             {