test: addmultisigaddress, coverage for script size limits

Author: furszy

test/functional/rpc_createmultisig.py

@@ -62,7 +62,7 @@ def run_test(self):
             for output_type in ["bech32", "p2sh-segwit", "legacy"]:
                 self.do_multisig(keys, sigs, output_type, wallet_multi)
 
-        self.test_multisig_script_limit()
+        self.test_multisig_script_limit(wallet_multi)
         self.test_mixing_uncompressed_and_compressed_keys(node0, wallet_multi)
         self.test_sortedmulti_descriptors_bip67()
 
@@ -84,7 +84,7 @@ def check_addmultisigaddress_errors(self):
         pubs = [self.nodes[1].getaddressinfo(addr)["pubkey"] for addr in addresses]
         assert_raises_rpc_error(-5, "Bech32m multisig addresses cannot be created with legacy wallets", self.nodes[0].addmultisigaddress, 2, pubs, "", "bech32m")
 
-    def test_multisig_script_limit(self):
+    def test_multisig_script_limit(self, wallet_multi):
         node1 = self.nodes[1]
         pubkeys = self.pub[0:20]
 
@@ -99,6 +99,17 @@ def test_multisig_script_limit(self):
         assert_raises_rpc_error(-8, "Number of keys involved in the multisignature address creation > 20", node1.createmultisig, 16, self.pub, 'p2sh-segwit')
         assert_raises_rpc_error(-8, "Number of keys involved in the multisignature address creation > 20", node1.createmultisig, 16, self.pub, 'bech32')
 
+        # Check legacy wallet related command
+        self.log.info('Test legacy redeem script max size limit (with wallet)')
+        if wallet_multi is not None and not self.options.descriptors:
+            assert_raises_rpc_error(-8, "redeemScript exceeds size limit: 684 > 520", wallet_multi.addmultisigaddress, 16, pubkeys, '', 'legacy')
+
+            self.log.info('Test legacy wallet unsupported operation. 16-20 multisig p2sh-legacy and bech32 generation')
+            # Due an internal limitation on legacy wallets, the redeem script limit also applies to p2sh-segwit and bech32 (even when the scripts are valid)
+            # We take this as a "good thing" to tell users to upgrade to descriptors.
+            assert_raises_rpc_error(-4, "Unsupported multisig script size for legacy wallet. Upgrade to descriptors to overcome this limitation for p2sh-segwit or bech32 scripts", wallet_multi.addmultisigaddress, 16, pubkeys, '', 'p2sh-segwit')
+            assert_raises_rpc_error(-4, "Unsupported multisig script size for legacy wallet. Upgrade to descriptors to overcome this limitation for p2sh-segwit or bech32 scripts", wallet_multi.addmultisigaddress, 16, pubkeys, '', 'bech32')
+
     def do_multisig(self, nkeys, nsigs, output_type, wallet_multi):
         node0, node1, node2 = self.nodes
         pub_keys = self.pub[0: nkeys]