rpc: add non-regression test about deriveaddresses crash when index is 2147483647

This test would cause a crash in bitcoind (see #26274) if the fix given in the
previous commit was not applied.

Github-Pull: #26275
Rebased-From: 9153ff3

Author: muxator

test/functional/rpc_deriveaddresses.py

@@ -44,6 +44,13 @@ def run_test(self):
         combo_descriptor = descsum_create("combo(tprv8ZgxMBicQKsPd7Uf69XL1XwhmjHopUGep8GuEiJDZmbQz6o58LninorQAfcKZWARbtRtfnLcJ5MQ2AtHcQJCCRUcMRvmDUjyEmNUWwx8UbK/1/1/0)")
         assert_equal(self.nodes[0].deriveaddresses(combo_descriptor), ["mtfUoUax9L4tzXARpw1oTGxWyoogp52KhJ", "mtfUoUax9L4tzXARpw1oTGxWyoogp52KhJ", address, "2NDvEwGfpEqJWfybzpKPHF2XH3jwoQV3D7x"])
 
+        # Before #26275, bitcoind would crash when deriveaddresses was
+        # called with derivation index 2147483647, which is the maximum
+        # positive value of a signed int32, and - currently - the
+        # maximum value that the deriveaddresses bitcoin RPC call
+        # accepts as derivation index.
+        assert_equal(self.nodes[0].deriveaddresses(descsum_create("wpkh(tprv8ZgxMBicQKsPd7Uf69XL1XwhmjHopUGep8GuEiJDZmbQz6o58LninorQAfcKZWARbtRtfnLcJ5MQ2AtHcQJCCRUcMRvmDUjyEmNUWwx8UbK/1/1/*)"), [2147483647, 2147483647]), ["bcrt1qtzs23vgzpreks5gtygwxf8tv5rldxvvsyfpdkg"])
+
         hardened_without_privkey_descriptor = descsum_create("wpkh(tpubD6NzVbkrYhZ4WaWSyoBvQwbpLkojyoTZPRsgXELWz3Popb3qkjcJyJUGLnL4qHHoQvao8ESaAstxYSnhyswJ76uZPStJRJCTKvosUCJZL5B/1'/1/0)")
         assert_raises_rpc_error(-5, "Cannot derive script without private keys", self.nodes[0].deriveaddresses, hardened_without_privkey_descriptor)