Select World: deleting the last world opens Create New World

WorldSelectionList.handleNewLevels opens a fresh CreateWorldScreen when
the singleplayer list comes back empty, with Cancel going to the title
screen. Horizon went back to an empty list instead.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/horizon-client/src/title.rs

@@ -298,15 +298,23 @@ impl Title {
             options: WorldOptions::default(),
         }
     }
+    /// WorldSelectionList.handleNewLevels: a singleplayer list that comes
+    /// back empty (the last world deleted, say) opens a fresh Create New
+    /// World, whose Cancel goes to the title screen.
     fn return_to_list(&mut self, folder: Option<&str>) {
         let worlds = list_worlds(&self.saves);
+        *self.recent.borrow_mut() = None;
+        if worlds.is_empty() {
+            self.create_return_to_main = true;
+            self.mode = Self::new_world();
+            return;
+        }
         let selected = folder.and_then(|folder| {
             worlds
                 .iter()
                 .position(|w| w.folder == folder && self.matches_search(w))
         });
         self.mode = Mode::Select { worlds, selected };
-        *self.recent.borrow_mut() = None;
     }
     /// Deletes the world `Mode::Delete` asks about and goes back to the
     /// refreshed list; a failure (the world is open elsewhere, say) shows the

crates/horizon-client/src/title/tests.rs

@@ -288,12 +288,37 @@ fn delete_requires_confirmation_and_both_cancel_paths_preserve_world() {
     assert_eq!((delete.x, delete.y, delete.w), (88.0, 146.0, 150.0));
     f.click("Delete");
     assert!(!f.title.saves.join("World").exists());
-    assert!(matches!(&f.title.mode, Mode::Select { worlds, selected: None } if worlds.is_empty()));
-    f.click("Back");
+    // The last world gone, vanilla opens a fresh Create New World, not an empty list.
+    assert!(matches!(&f.title.mode, Mode::Create { name, .. } if name == "New World"));
+    f.click("Cancel");
+    assert!(matches!(f.title.mode, Mode::Main));
     f.click("Singleplayer");
     assert!(matches!(f.title.mode, Mode::Create { .. }));
 }
 
+#[test]
+fn deleting_one_of_two_worlds_keeps_the_list() {
+    let mut f = Fixture::new();
+    f.world("One", "One");
+    f.world("Two", "Two");
+    f.select();
+    f.click("Delete");
+    f.click("Delete");
+    assert!(matches!(&f.title.mode, Mode::Select { worlds, .. } if worlds.len() == 1));
+}
+
+#[test]
+fn a_list_emptied_elsewhere_opens_create_world() {
+    let mut f = Fixture::new();
+    f.world("World", "World");
+    f.title.enter_singleplayer();
+    world_management::delete(&f.title.saves, "World").unwrap();
+    f.title.worlds_changed();
+    assert!(matches!(f.title.mode, Mode::Create { .. }));
+    f.title.escape();
+    assert!(matches!(f.title.mode, Mode::Main));
+}
+
 #[test]
 fn backup_zip_preserves_nested_files_excludes_lock_and_keeps_duplicate_backups() {
     let f = Fixture::new();
@@ -600,7 +625,7 @@ fn world_management_buttons_sound_when_enabled() {
     assert_eq!(f.click_with_sound("Cancel"), (Action::None, true));
     assert_eq!(f.click_with_sound("Delete"), (Action::None, true));
     assert_eq!(f.click_with_sound("Delete"), (Action::None, true));
-    assert!(matches!(f.title.mode, Mode::Select { .. }));
+    assert!(matches!(f.title.mode, Mode::Create { .. }));
 }
 
 #[test]