feat(runtime): prepare safe context checkpoints

src-tauri/icons/android/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+  <background android:drawable="@color/ic_launcher_background"/>
+</adaptive-icon>

src-tauri/icons/android/values/ic_launcher_background.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="ic_launcher_background">#fff</color>
+</resources>

src-tauri/src/lib.rs

@@ -515,6 +515,7 @@ impl DemoAppState {
             .get("nana.ending.returned_before_dawn")
             .copied()
             .unwrap_or(false)
+            && request.intent != TurnIntent::Regenerate
         {
             return Err(CommandError::invalid_input(
                 "这一夜的故事已经结束；可从回溯中选择另一条线路。",
@@ -965,7 +966,16 @@ impl TurnPlanProvider for DemoPlanProvider {
                     )
             });
 
-        let (beats, delta, suggestions, can_continue) = if accepted_promise {
+        let (beats, delta, suggestions, can_continue) = if request.intent == TurnIntent::Regenerate
+        {
+            let (beats, delta) = regular_turn(request);
+            let ending = state
+                .world_flags
+                .get("nana.ending.returned_before_dawn")
+                .copied()
+                .unwrap_or(false);
+            (beats, delta, Vec::new(), !ending)
+        } else if accepted_promise {
             let (beats, delta) = promise_turn(request, &committed_node_id);
             (beats, delta, investigation_suggestions(), true)
         } else if state
@@ -2188,6 +2198,47 @@ mod tests {
         }
     }
 
+    fn assert_ending_can_be_regenerated(app: &DemoAppState, ending_node_id: &str) {
+        let rejected = app
+            .submit_turn(&continue_request(
+                DEMO_BRANCH_ID,
+                ending_node_id,
+                "action_after_ending",
+            ))
+            .expect_err("ending is terminal");
+        assert_eq!(rejected.code, "invalid_input");
+        assert_eq!(
+            app.store
+                .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
+                .expect("unchanged ending")
+                .current_node,
+            ending_node_id
+        );
+
+        let mut regenerate =
+            continue_request(DEMO_BRANCH_ID, ending_node_id, "action_regenerate_ending");
+        regenerate.intent = TurnIntent::Regenerate;
+        regenerate.input = "this request text must not replace the original action".to_owned();
+        let regenerated = app
+            .submit_turn(&regenerate)
+            .expect("ending presentation can be regenerated");
+        assert_ne!(regenerated.player_view.branch_id, DEMO_BRANCH_ID);
+        assert!(!regenerated.player_view.can_continue);
+        assert_eq!(
+            app.store
+                .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
+                .expect("original ending branch retained")
+                .current_node,
+            ending_node_id
+        );
+        let regenerated_node = app
+            .store
+            .load_node(DEMO_STORY_ID, &regenerated.committed_node_id)
+            .expect("regenerated ending node");
+        assert_eq!(regenerated_node.action_id, "action_return_before_dawn");
+        assert!(regenerated_node.user_input.is_empty());
+    }
+
     fn node(id: &str, parent_id: Option<&str>, ops: Vec<StateOp>) -> StoryNode {
         StoryNode {
             id: id.to_owned(),
@@ -2312,21 +2363,7 @@ mod tests {
                 .get("nana.ending.returned_before_dawn"),
             Some(&true)
         );
-        let rejected = app
-            .submit_turn(&continue_request(
-                DEMO_BRANCH_ID,
-                &returned.committed_node_id,
-                "action_after_ending",
-            ))
-            .expect_err("ending is terminal");
-        assert_eq!(rejected.code, "invalid_input");
-        assert_eq!(
-            app.store
-                .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
-                .expect("unchanged ending")
-                .current_node,
-            returned.committed_node_id
-        );
+        assert_ending_can_be_regenerated(&app, &returned.committed_node_id);
     }
 
     #[test]