engine: restore tabs closed inside a failed command group

crates/engine/src/batch_rollback_tests.rs

@@ -34,6 +34,28 @@ fn failed_group_closes_documents_opened_inside_it() {
     assert_eq!(s.journal, before_journal);
 }
 
+#[test]
+fn failed_group_reopens_documents_closed_inside_it() {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"name": "Second"})).unwrap();
+    assert_eq!((s.docs.len(), s.active), (2, 1));
+
+    let result = s.execute(
+        "command.batch",
+        &json!({
+            "commands": [
+                {"command": "file.close", "params": {"index": 1, "force": true}},
+                {"command": "node.set", "params": {"id": 999999, "props": {"name": "must fail"}}}
+            ]
+        }),
+    );
+
+    assert!(result.is_err());
+    assert_eq!(s.docs.len(), 2);
+    assert_eq!(s.active, 1);
+    assert!(s.ds().is_ok());
+}
+
 #[test]
 fn failed_plugin_run_restores_each_document_without_restoring_unrelated_state() {
     let mut s = Session::new();

crates/engine/src/lib.rs

@@ -1277,6 +1277,8 @@ impl Session {
             self.docs.iter().map(|ds| (ds.uid, ds.doc.clone(), ds.selection.clone(), ds.page, ds.history.undo.len(), ds.history.limit)).collect();
         // An edit inside clears the redo steps; a failed group has to bring them back.
         let redo_before: Vec<_> = self.docs.iter().map(|ds| ds.history.redo.clone()).collect();
+        // Tabs the group closes (or reorders) come back from this.
+        let tabs_before = self.docs.clone();
         let active = self.active;
         let journal_len = self.journal.len();
 
@@ -1293,7 +1295,14 @@ impl Session {
         }
 
         if result.is_err() {
-            self.docs.retain(|ds| before.iter().any(|(uid, _, _, _, _, _)| *uid == ds.uid));
+            let mut current = std::mem::take(&mut self.docs);
+            self.docs = tabs_before
+                .into_iter()
+                .map(|t| match current.iter().position(|d| d.uid == t.uid) {
+                    Some(i) => current.swap_remove(i),
+                    None => t,
+                })
+                .collect();
             for ((uid, doc, selection, page, undo_len, limit), redo) in before.iter().zip(redo_before) {
                 if let Some(ds) = self.docs.iter_mut().find(|ds| ds.uid == *uid) {
                     ds.history.redo = redo;