Merge bitcoin#28067: descriptors: do not return top-level only funcs as sub descriptors

dd9633b test: wallet, add coverage for watch-only raw sh script migration (furszy)
cc781a2 descriptor: InferScript, do not return top-level only func as sub descriptor (furszy)
286e0c7 wallet: loading, log descriptor parsing error details (furszy)

Pull request description:

  Linked to bitcoin#28057.

  Currently, the `InferScript` function returns an invalid descriptor when it tries to infer a p2sh-p2pkh script whose pubkey is not known by the wallet.

  This behavior occurs because the inference process bypasses the `pkh` subscript when the pubkey is not contained by the wallet (no pubkey provider), interpreting it as a `sh(addr(ADDR))` descriptor. Then, the failure arises because the `addr()` function is restricted to being used only at the top level.

  For reviewers, would recommend to start by examining the functional test to understand the context and the circumstances on which this can result in a fatal error (e.g. during the migration process).

ACKs for top commit:
  achow101:
    ACK dd9633b
  darosior:
    utACK dd9633b

Tree-SHA512: 61e763206c604c372019d2c36e31684f3dddf81f8b154eb9aba5cd66d8d61bda457ed4e591613eb6ce6c76cf7c3f11764abc6cd727a7c2b6414f1065783be032

Author: achow101

src/script/descriptor.cpp

@@ -1723,6 +1723,10 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
         }
     }
 
+    // The following descriptors are all top-level only descriptors.
+    // So if we are not at the top level, return early.
+    if (ctx != ParseScriptContext::TOP) return nullptr;
+
     CTxDestination dest;
     if (ExtractDestination(script, dest)) {
         if (GetScriptForDestination(dest) == script) {

src/wallet/walletdb.cpp

@@ -794,11 +794,13 @@ static DBErrors LoadDescriptorWalletRecords(CWallet* pwallet, DatabaseBatch& bat
         WalletDescriptor desc;
         try {
             value >> desc;
-        } catch (const std::ios_base::failure&) {
+        } catch (const std::ios_base::failure& e) {
             strErr = strprintf("Error: Unrecognized descriptor found in wallet %s. ", pwallet->GetName());
             strErr += (last_client > CLIENT_VERSION) ? "The wallet might had been created on a newer version. " :
                     "The database might be corrupted or the software version is not compatible with one of your wallet descriptors. ";
             strErr += "Please try running the latest software version";
+            // Also include error details
+            strErr = strprintf("%s\nDetails: %s", strErr, e.what());
             return DBErrors::UNKNOWN_DESCRIPTOR;
         }
         pwallet->LoadDescriptorScriptPubKeyMan(id, desc);

test/functional/data/rpc_decodescript.json

@@ -69,7 +69,7 @@
             "p2sh": "2N34iiGoUUkVSPiaaTFpJjB1FR9TXQu3PGM",
             "segwit": {
                 "asm": "0 96c2368fc30514a438a8bd909f93c49a1549d77198ccbdb792043b666cb24f42",
-                "desc": "wsh(raw(02eeee))#gtay4y0z",
+                "desc": "addr(bcrt1qjmprdr7rq522gw9ghkgfly7yng25n4m3nrxtmdujqsakvm9jfapqk795l5)#5akkdska",
                 "hex": "002096c2368fc30514a438a8bd909f93c49a1549d77198ccbdb792043b666cb24f42",
                 "address": "bcrt1qjmprdr7rq522gw9ghkgfly7yng25n4m3nrxtmdujqsakvm9jfapqk795l5",
                 "type": "witness_v0_scripthash",

test/functional/rpc_decodescript.py

@@ -271,7 +271,7 @@ def decodescript_miniscript(self):
         assert res["segwit"]["desc"] == "wsh(and_v(and_v(v:hash160(ffffffffffffffffffffffffffffffffffffffff),v:pk(0250929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0)),older(1)))#gm8xz4fl"
         # Miniscript-incompatible offered HTLC
         res = self.nodes[0].decodescript("82012088a914ffffffffffffffffffffffffffffffffffffffff882102ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffacb2")
-        assert res["segwit"]["desc"] == "wsh(raw(82012088a914ffffffffffffffffffffffffffffffffffffffff882102ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffacb2))#ra6w2xa7"
+        assert res["segwit"]["desc"] == "addr(bcrt1q73qyfypp47hvgnkjqnav0j3k2lq3v76wg22dk8tmwuz5sfgv66xsvxg6uu)#9p3q328s"
         # Miniscript-compatible multisig bigger than 520 byte P2SH limit.
         res = self.nodes[0].decodescript("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")
         assert_equal(res["segwit"]["desc"], "wsh(or_d(multi(11,020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261,02675333a4e4b8fb51d9d4e22fa5a8eaced3fdac8a8cbf9be8c030f75712e6af99,02896807d54bc55c24981f24a453c60ad3e8993d693732288068a23df3d9f50d48,029e51a5ef5db3137051de8323b001749932f2ff0d34c82e96a2c2461de96ae56c,02a4e1a9638d46923272c266631d94d36bdb03a64ee0e14c7518e49d2f29bc4010,031c41fdbcebe17bec8d49816e00ca1b5ac34766b91c9f2ac37d39c63e5e008afb,03079e252e85abffd3c401a69b087e590a9b86f33f574f08129ccbd3521ecf516b,03111cf405b627e22135b3b3733a4a34aa5723fb0f58379a16d32861bf576b0ec2,0318f331b3e5d38156da6633b31929c5b220349859cc9ca3d33fb4e68aa0840174,03230dae6b4ac93480aeab26d000841298e3b8f6157028e47b0897c1e025165de1,035abff4281ff00660f99ab27bb53e6b33689c2cd8dcd364bc3c90ca5aea0d71a6,03bd45cddfacf2083b14310ae4a84e25de61e451637346325222747b157446614c,03cc297026b06c71cbfa52089149157b5ff23de027ac5ab781800a578192d17546,03d3bde5d63bdb3a6379b461be64dad45eabff42f758543a9645afd42f6d424828,03ed1e8d5109c9ed66f7941bc53cc71137baa76d50d274bda8d5e8ffbd6e61fe9a),and_v(v:older(4032),multi(2,03aab896d53a8e7d6433137bbba940f9c521e085dd07e60994579b64a6d992cf79,0291b7d0b1b692f8f524516ed950872e5da10fb1b808b5a526dedc6fed1cf29807,0386aa9372fbab374593466bc5451dc59954e90787f08060964d95c87ef34ca5bb))))#7jwwklk4")

test/functional/wallet_migration.py

@@ -8,6 +8,8 @@
 import shutil
 from test_framework.descriptors import descsum_create
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.messages import COIN, CTransaction, CTxOut
+from test_framework.script_util import key_to_p2pkh_script, script_to_p2sh_script, script_to_p2wsh_script
 from test_framework.util import (
     assert_equal,
     assert_raises_rpc_error,
@@ -639,6 +641,53 @@ def check(info, node):
         for addr_info in [addr_external, addr_external_with_label]:
             check(addr_info, wallet_solvables)
 
+    def test_migrate_raw_p2sh(self):
+        self.log.info("Test migration of watch-only raw p2sh script")
+        df_wallet = self.nodes[0].get_wallet_rpc(self.default_wallet_name)
+        wallet = self.create_legacy_wallet("raw_p2sh")
+
+        def send_to_script(script, amount):
+            tx = CTransaction()
+            tx.vout.append(CTxOut(nValue=amount*COIN, scriptPubKey=script))
+
+            hex_tx = df_wallet.fundrawtransaction(tx.serialize().hex())['hex']
+            signed_tx = df_wallet.signrawtransactionwithwallet(hex_tx)
+            df_wallet.sendrawtransaction(signed_tx['hex'])
+            self.generate(self.nodes[0], 1)
+
+        # Craft sh(pkh(key)) script and send coins to it
+        pubkey = df_wallet.getaddressinfo(df_wallet.getnewaddress())["pubkey"]
+        script_pkh = key_to_p2pkh_script(pubkey)
+        script_sh_pkh = script_to_p2sh_script(script_pkh)
+        send_to_script(script=script_sh_pkh, amount=2)
+
+        # Import script and check balance
+        wallet.rpc.importaddress(address=script_pkh.hex(), label="raw_spk", rescan=True, p2sh=True)
+        assert_equal(wallet.getbalances()['watchonly']['trusted'], 2)
+
+        # Craft wsh(pkh(key)) and send coins to it
+        pubkey = df_wallet.getaddressinfo(df_wallet.getnewaddress())["pubkey"]
+        script_wsh_pkh = script_to_p2wsh_script(key_to_p2pkh_script(pubkey))
+        send_to_script(script=script_wsh_pkh, amount=3)
+
+        # Import script and check balance
+        wallet.rpc.importaddress(address=script_wsh_pkh.hex(), label="raw_spk2", rescan=True, p2sh=False)
+        assert_equal(wallet.getbalances()['watchonly']['trusted'], 5)
+
+        # Migrate wallet and re-check balance
+        info_migration = wallet.migratewallet()
+        wallet_wo = self.nodes[0].get_wallet_rpc(info_migration["watchonly_name"])
+
+        # Watch-only balance is under "mine".
+        assert_equal(wallet_wo.getbalances()['mine']['trusted'], 5)
+        # The watch-only scripts are no longer part of the main wallet
+        assert_equal(wallet.getbalances()['mine']['trusted'], 0)
+
+        # Just in case, also verify wallet restart
+        self.nodes[0].unloadwallet(info_migration["watchonly_name"])
+        self.nodes[0].loadwallet(info_migration["watchonly_name"])
+        assert_equal(wallet_wo.getbalances()['mine']['trusted'], 5)
+
     def run_test(self):
         self.generate(self.nodes[0], 101)
 
@@ -654,6 +703,7 @@ def run_test(self):
         self.test_default_wallet()
         self.test_direct_file()
         self.test_addressbook()
+        self.test_migrate_raw_p2sh()
 
 if __name__ == '__main__':
     WalletMigrationTest().main()