rpc: Include assumeutxo as a failure reason of rescanblockchain

bitcoin/bitcoin@42d5d53
bitcoin/bitcoin@9d2d9f7

Author: fjahr

src/interfaces/chain.h

@@ -228,6 +228,9 @@ class Chain {
     //! Check if any block has been pruned.
     virtual bool havePruned() = 0;
 
+    //! Get the current prune height.
+    virtual std::optional<int> getPruneHeight() = 0;
+
     //! Check if the node is ready to broadcast transactions.
     virtual bool isReadyToBroadcast() = 0;
 

src/node/interfaces.cpp

@@ -27,6 +27,7 @@
 #include <policy/settings.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
+#include <rpc/blockchain.h>
 #include <rpc/protocol.h>
 #include <rpc/server.h>
 #include <shutdown.h>
@@ -716,6 +717,10 @@ namespace {
             return !chainman().m_blockman.LoadingBlocks() &&
                    !isInitialBlockDownload();
         }
+        std::optional<int> getPruneHeight() override {
+            LOCK(chainman().GetMutex());
+            return GetPruneHeight(chainman().m_blockman, chainman().ActiveChain());
+        }
         bool isInitialBlockDownload() override {
             return chainman().IsInitialBlockDownload();
         }

src/wallet/rpcwallet.cpp

@@ -3767,14 +3767,29 @@ RPCHelpMan rescanblockchain() {
                     }
                 }
 
-                // We can't rescan beyond non-pruned blocks, stop and throw an
-                // error
+                // We can't rescan unavailable blocks, stop and throw an error
                 if (!pwallet->chain().hasBlocks(pwallet->GetLastBlockHash(),
                                                 start_height, stop_height)) {
+                    if (pwallet->chain().havePruned() &&
+                        pwallet->chain().getPruneHeight() >= start_height) {
+                        throw JSONRPCError(RPC_MISC_ERROR,
+                                           "Can't rescan beyond pruned data. "
+                                           "Use RPC call getblockchaininfo to "
+                                           "determine your pruned height.");
+                    }
+                    if (pwallet->chain().hasAssumedValidChain()) {
+                        throw JSONRPCError(
+                            RPC_MISC_ERROR,
+                            "Failed to rescan unavailable blocks likely due to "
+                            "an in-progress assumeutxo background sync. Check "
+                            "logs or getchainstates RPC for assumeutxo "
+                            "background sync progress and try again later.");
+                    }
                     throw JSONRPCError(
                         RPC_MISC_ERROR,
-                        "Can't rescan beyond pruned data. Use RPC call "
-                        "getblockchaininfo to determine your pruned height.");
+                        "Failed to rescan unavailable blocks, potentially "
+                        "caused by data corruption. If the issue persists you "
+                        "may want to reindex (see -reindex option).");
                 }
 
                 CHECK_NONFATAL(pwallet->chain().findAncestorByHeight(

test/functional/wallet_assumeutxo.py

@@ -161,10 +161,10 @@ def run_test(self):
         self.log.info("Backup from before the snapshot height can't be loaded during background sync")
         assert_raises_rpc_error(-4, "Wallet loading failed. Error loading wallet. Wallet requires blocks to be downloaded, and software does not currently support loading wallets while blocks are being downloaded out of order when using assumeutxo snapshots. Wallet should be able to load successfully after node sync reaches height 299", n1.restorewallet, "w2", "backup_w2.dat")
 
+        wallet_name = "w1"
+        n1.createwallet(wallet_name, disable_private_keys=True)
         if self.options.descriptors:
             self.log.info("Test loading descriptors during background sync")
-            wallet_name = "w1"
-            n1.createwallet(wallet_name, disable_private_keys=True)
             key = get_generate_key()
             time = n1.getblockchaininfo()['time']
             timestamp = 0
@@ -181,6 +181,10 @@ def run_test(self):
             assert_equal(result[0]['error']['code'], -1)
             assert_equal(result[0]['error']['message'], expected_error_message)
 
+        self.log.info("Test that rescanning blocks from before the snapshot fails when blocks are not available from the background sync yet")
+        w1 = n1.get_wallet_rpc(wallet_name)
+        assert_raises_rpc_error(-1, "Failed to rescan unavailable blocks likely due to an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later.", w1.rescanblockchain, 100)
+
         PAUSE_HEIGHT = FINAL_HEIGHT - 40
 
         self.log.info("Restarting node to stop at height %d", PAUSE_HEIGHT)