Persist cached SPKs on wallet creation

Author: j-kon

src/wallet/mod.rs

@@ -2838,7 +2838,7 @@ fn make_indexed_graph(
     use_spk_cache: bool,
 ) -> Result<IndexedTxGraph<ConfirmationBlockTime, KeychainTxOutIndex<KeychainKind>>, DescriptorError>
 {
-    let (indexed_graph, changeset) = IndexedTxGraph::from_changeset(
+    let (mut indexed_graph, changeset) = IndexedTxGraph::from_changeset(
         chain::indexed_tx_graph::ChangeSet {
             tx_graph: tx_graph_changeset,
             indexer: indexer_changeset,
@@ -2880,8 +2880,19 @@ fn make_indexed_graph(
             Ok(idx)
         },
     )?;
+    // `insert_descriptor` stages any newly derived lookahead SPKs inside the indexer, but
+    // `IndexedTxGraph::from_changeset` only returns reindexing changes. Flush the stage here so
+    // wallet creation persists the initial SPK cache.
+    let mut initial_indexer_changeset = indexed_graph
+        .index
+        .index_txout(OutPoint::null(), &TxOut::NULL);
+    initial_indexer_changeset
+        .spk_cache
+        .retain(|_, spks| !spks.is_empty());
+
     stage.tx_graph.merge(changeset.tx_graph);
     stage.indexer.merge(changeset.indexer);
+    stage.indexer.merge(initial_indexer_changeset);
     Ok(indexed_graph)
 }
 

tests/persisted_wallet.rs

@@ -101,22 +101,39 @@ fn wallet_is_persisted() -> anyhow::Result<()> {
         let (external_desc, internal_desc) = get_test_tr_single_sig_xprv_and_change_desc();
 
         // create new wallet
-        let wallet_spk_index = {
+        {
             let mut db = create_db(&file_path)?;
-            let mut wallet = Wallet::create(external_desc, internal_desc)
+            let wallet = Wallet::create(external_desc, internal_desc)
                 .network(Network::Testnet)
                 .use_spk_cache(true)
                 .create_wallet(&mut db)?;
 
-            wallet.reveal_next_address(KeychainKind::External);
+            assert!(
+                wallet.staged().is_none(),
+                "persisted wallet creation should write the initial changeset"
+            );
+        }
+
+        // reload immediately to ensure the initial cached SPKs were persisted at creation time
+        let wallet_spk_index = {
+            let mut db = open_db(&file_path)?;
+            let mut wallet = Wallet::load()
+                .check_network(Network::Testnet)
+                .use_spk_cache(true)
+                .load_wallet(&mut db)?
+                .expect("wallet must exist");
+
+            assert!(wallet.staged().is_none());
+
+            let revealed_external_addr = wallet.reveal_next_address(KeychainKind::External);
 
             check_cache_cs(
                 &staged_cache(&wallet),
-                [
-                    (KeychainKind::External, 0..DEFAULT_LOOKAHEAD + 1),
-                    (KeychainKind::Internal, 0..DEFAULT_LOOKAHEAD),
-                ],
-                "cache cs must return initial set + the external index that was just derived",
+                [(
+                    KeychainKind::External,
+                    [revealed_external_addr.index + DEFAULT_LOOKAHEAD],
+                )],
+                "initial cached SPKs should already be persisted at wallet creation",
             );
 
             // persist new wallet changes