Merge bitcoin/bitcoin#26116: rpc: Allow importmulti watchonly imports with locked wallet

2c03465 test: Test watchonly imports with passphrase-locked wallet (Aurèle Oulès)
1fcf9e6 rpc: Allow importmulti watchonly imports with locked wallet (Aurèle Oulès)

Pull request description:

  Allows watch-only imports on locked wallets with `importmulti`.
  Also adds a test.

  Fixes #17867.

ACKs for top commit:
  achow101:
    ACK 2c03465
  kristapsk:
    re-ACK 2c03465
  theStack:
    re-ACK 2c03465

Tree-SHA512: 9978d6e59a230c0d160efd312c671cf59458797387d6622b6bf5c9e0681c1fcfebedb3d834fa9314dc5a1eda97e3295696352eacbeab9b43a46b942990087035

Author: achow101

src/wallet/rpc/backup.cpp

@@ -1363,7 +1363,18 @@ RPCHelpMan importmulti()
     UniValue response(UniValue::VARR);
     {
         LOCK(pwallet->cs_wallet);
-        EnsureWalletIsUnlocked(*pwallet);
+
+        // Check all requests are watchonly
+        bool is_watchonly{true};
+        for (size_t i = 0; i < requests.size(); ++i) {
+            const UniValue& request = requests[i];
+            if (!request.exists("watchonly") || !request["watchonly"].get_bool()) {
+                is_watchonly = false;
+                break;
+            }
+        }
+        // Wallet does not need to be unlocked if all requests are watchonly
+        if (!is_watchonly) EnsureWalletIsUnlocked(wallet);
 
         // Verify all timestamps are present before importing any keys.
         CHECK_NONFATAL(pwallet->chain().findBlock(pwallet->GetLastBlockHash(), FoundBlock().time(nLowestTimestamp).mtpTime(now)));

test/functional/wallet_importmulti.py

@@ -874,6 +874,25 @@ def run_test(self):
             addr = wrpc.getnewaddress('', 'bech32')
             assert_equal(addr, addresses[i])
 
+        # Create wallet with passphrase
+        self.log.info('Test watchonly imports on a wallet with a passphrase, without unlocking')
+        self.nodes[1].createwallet(wallet_name='w1', blank=True, passphrase='pass')
+        wrpc = self.nodes[1].get_wallet_rpc('w1')
+        assert_raises_rpc_error(-13, "Please enter the wallet passphrase with walletpassphrase first.",
+                                wrpc.importmulti, [{
+                                    'desc': descsum_create('wpkh(' + pub1 + ')'),
+                                    "timestamp": "now",
+                                }])
+
+        result = wrpc.importmulti(
+            [{
+                'desc': descsum_create('wpkh(' + pub1 + ')'),
+                "timestamp": "now",
+                "watchonly": True,
+            }]
+        )
+        assert result[0]['success']
+
 
 if __name__ == '__main__':
     ImportMultiTest().main()