Remember last selected ROM on load failure

src/nese.c

@@ -112,6 +112,10 @@ static int select_rom(menu_state* menu,
                       cart_info* cur_cart) {
     int status = 0;
     cart_info cart = {0};
+    cart_info ref_cart = {
+        .filename = cur_cart->filename,
+        .file = cur_cart->file,
+    };
     nes_cart new_cart = {0};
 
     while (0 == status && NULL == cart.file) {
@@ -125,22 +129,22 @@ static int select_rom(menu_state* menu,
                 // Program closed inside modal
                 status = input_Result_Quit;
             }
-            free(cart.filename);
-            cart.filename = NULL;
         }
 
         if (0 == status) {
-            cart.filename = run_main_menu(menu, comp, cur_cart);
+            char* new_filename = run_main_menu(menu, comp,
+                                               &ref_cart);
 
-            if ((char*)-1 == cart.filename) {
-                // This means that we quit
+            if ((char*)-1 == new_filename) {
                 status = input_Result_Quit;
 
-            } else if (NULL == cart.filename) {
-                // This means we didn't press "cancel"
+            } else if (NULL == new_filename) {
                 status = input_Result_Cancel;
 
             } else {
+                free(cart.filename);
+                cart.filename = new_filename;
+                ref_cart.filename = new_filename;
                 cart.file = nes_load_cart(&new_cart,
                                           cart.filename);
             }
@@ -157,6 +161,9 @@ static int select_rom(menu_state* menu,
         *cur_cart = cart;
 
         nes_setup_cart(comp->sys);
+
+    } else {
+        free(cart.filename);
     }
 
     return status;