fix(core): a folder listed just as its create lands is listed from the database (B177)

crates/pdfs-core/src/db/nodes.rs

@@ -533,9 +533,10 @@ impl Db {
     /// re-enumerates from the remote on next access.
     pub fn set_listed(&self, uid: &NodeUid, listed: bool) -> Result<()> {
         let conn = self.conn.lock();
+        let (key, uid) = row_key(&uid.to_string());
         conn.execute(
-            "UPDATE nodes SET listed = ?2 WHERE uid = ?1",
-            params![uid.to_string(), listed as i64],
+            &format!("UPDATE nodes SET listed = ?2 WHERE {key} = ?1"),
+            params![uid, listed as i64],
         )?;
         Ok(())
     }
@@ -694,10 +695,11 @@ impl Db {
     /// server head, so changes made while unmounted are still applied (P2).
     pub fn children_if_listed(&self, parent: &NodeUid) -> Result<Option<Vec<Node>>> {
         let conn = self.read();
+        let (key, folder) = row_key(&parent.to_string());
         let listed: Option<i64> = conn
             .query_row(
-                "SELECT listed FROM nodes WHERE uid = ?1",
-                params![parent.to_string()],
+                &format!("SELECT listed FROM nodes WHERE {key} = ?1"),
+                params![folder],
                 |r| r.get(0),
             )
             .optional()?;
@@ -792,6 +794,17 @@ pub(super) fn node_lid(conn: &rusqlite::Connection, uid: &str) -> Result<Option<
     Ok(row.optional()?)
 }
 
+/// The column and value that find `uid`'s own row. A stand-in is found by its
+/// local id: a create that lands gives the row the uid Drive made before the
+/// tree has it, and the tree asks by the stand-in until then (`docs/BUGS.md`
+/// B177).
+fn row_key(uid: &str) -> (&'static str, Value) {
+    match local_lid(uid) {
+        Some(lid) => ("lid", Value::Integer(lid)),
+        None => ("uid", Value::Text(uid.to_owned())),
+    }
+}
+
 /// The column and value a row names `parent` by: its local id when it has a
 /// row, which the children keep when it lands, or its uid when it has none,
 /// as a device folder's root does.

crates/pdfs-core/src/db/tests.rs

@@ -3282,6 +3282,37 @@ fn a_stand_in_keeps_its_access_once_its_create_has_landed() {
     );
 }
 
+#[test]
+fn a_stand_in_folder_stays_listed_once_its_create_has_landed() {
+    let db = Db::open_in_memory().unwrap();
+    db.upsert_node(&folder("parent", None, "My Files")).unwrap();
+    let parent = uid("parent").to_string();
+    let lid = db.add_local_row(&parent, "dir", true, 1).unwrap();
+    let local = local_uid(lid);
+    let stand_in = NodeUid::new(VolumeId::from("local"), LinkId::from(lid.to_string()));
+    let mut node = folder("new", Some("parent"), "dir");
+    node.uid = stand_in.clone();
+    db.upsert_node(&node).unwrap();
+    db.set_listed(&stand_in, true).unwrap();
+    let real = uid("real").to_string();
+    let (id, _) = db
+        .enqueue_op(&op_on(OP_MKDIR, &local, Some(&parent)))
+        .unwrap();
+    db.claim_next_due_op(1).unwrap().unwrap();
+    db.finish_create(id, None, &landing(&local, &real, &parent, "dir"), |_| None)
+        .unwrap();
+
+    // The tree still names the folder by its stand-in for a moment; a listing
+    // asked by it must not go to Drive, which has never heard of it.
+    assert!(
+        db.children_if_listed(&stand_in)
+            .unwrap()
+            .is_some_and(|kids| kids.is_empty())
+    );
+    db.set_listed(&stand_in, false).unwrap();
+    assert!(db.children_if_listed(&uid("real")).unwrap().is_none());
+}
+
 #[test]
 fn a_node_queued_under_both_its_uids_is_sent_one_op_at_a_time() {
     let db = Db::open_in_memory().unwrap();