rpc: Add missing BlockUntilSyncedToCurrentChain to wallet RPCs

Wallet RPCs that allow a rescan based on block-timestamp or block-height
need to sync with the active chain first, because the user might assume
the wallet is up-to-date with the latest block they got reported via a
blockchain RPC.

src/wallet/rpc/backup.cpp

@@ -1346,6 +1346,11 @@ RPCHelpMan importmulti()
 {
     std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(mainRequest);
     if (!pwallet) return NullUniValue;
+    CWallet& wallet{*pwallet};
+
+    // Make sure the results are valid at least up to the most recent block
+    // the user could have gotten from another RPC command prior to now
+    wallet.BlockUntilSyncedToCurrentChain();
 
     RPCTypeCheck(mainRequest.params, {UniValue::VARR, UniValue::VOBJ});
 
@@ -1649,6 +1654,11 @@ RPCHelpMan importdescriptors()
 {
     std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(main_request);
     if (!pwallet) return NullUniValue;
+    CWallet& wallet{*pwallet};
+
+    // Make sure the results are valid at least up to the most recent block
+    // the user could have gotten from another RPC command prior to now
+    wallet.BlockUntilSyncedToCurrentChain();
 
     //  Make sure wallet is a descriptor wallet
     if (!pwallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {

src/wallet/rpcwallet.cpp

@@ -3304,6 +3304,11 @@ static RPCHelpMan rescanblockchain()
 {
     std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
     if (!pwallet) return NullUniValue;
+    CWallet& wallet{*pwallet};
+
+    // Make sure the results are valid at least up to the most recent block
+    // the user could have gotten from another RPC command prior to now
+    wallet.BlockUntilSyncedToCurrentChain();
 
     WalletRescanReserver reserver(*pwallet);
     if (!reserver.reserve()) {

test/functional/wallet_importmulti.py

@@ -65,7 +65,6 @@ class ImportMultiTest(BitcoinTestFramework):
         self.generate(self.nodes[0], 1, sync_fun=self.no_op)
         self.generate(self.nodes[1], 1, sync_fun=self.no_op)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()  # Sync the timestamp to the wallet, so that importmulti works
 
         node0_address1 = self.nodes[0].getaddressinfo(self.nodes[0].getnewaddress())
 
@@ -260,7 +259,6 @@ class ImportMultiTest(BitcoinTestFramework):
         self.nodes[1].sendtoaddress(multisig.p2sh_addr, 10.00)
         self.generate(self.nodes[1], 1, sync_fun=self.no_op)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()
 
         self.log.info("Should import a p2sh")
         self.test_importmulti({"scriptPubKey": {"address": multisig.p2sh_addr},
@@ -281,7 +279,6 @@ class ImportMultiTest(BitcoinTestFramework):
         self.nodes[1].sendtoaddress(multisig.p2sh_addr, 10.00)
         self.generate(self.nodes[1], 1, sync_fun=self.no_op)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()
 
         self.log.info("Should import a p2sh with respective redeem script")
         self.test_importmulti({"scriptPubKey": {"address": multisig.p2sh_addr},
@@ -302,7 +299,6 @@ class ImportMultiTest(BitcoinTestFramework):
         self.nodes[1].sendtoaddress(multisig.p2sh_addr, 10.00)
         self.generate(self.nodes[1], 1, sync_fun=self.no_op)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()
 
         self.log.info("Should import a p2sh with respective redeem script and private keys")
         self.test_importmulti({"scriptPubKey": {"address": multisig.p2sh_addr},
@@ -328,7 +324,6 @@ class ImportMultiTest(BitcoinTestFramework):
         self.nodes[1].sendtoaddress(multisig.p2sh_addr, 10.00)
         self.generate(self.nodes[1], 1, sync_fun=self.no_op)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()
 
         self.log.info("Should import a p2sh with respective redeem script and private keys")
         self.test_importmulti({"scriptPubKey": {"address": multisig.p2sh_addr},