Merge bitcoin/bitcoin#23642: refactor: Call type-solver earlier in decodescript

3333070 refactor: Call type-solver earlier in decodescript (MarcoFalke)
fab0d99 style: Remove whitespace (MarcoFalke)

Pull request description:

  The current logic is a bit confusing. First creating the `UniValue` return dict, then parsing it again to get the type as `std::string`.

  Clean this up by using a strong type `TxoutType`. Also, remove whitespace.

ACKs for top commit:
  shaavan:
    ACK 3333070
  theStack:
    Code-review ACK 3333070

Tree-SHA512: 49db7bc614d2491cd3ec0177d21ad1e9924dbece1eb5635290cd7fd18cb30adf4711b891daf522e7c4f6baab3033b66393bbfcd1d4726f24f90a433124f925d6

Author: MarcoFalke

src/rpc/rawtransaction.cpp

@@ -540,32 +540,33 @@ static std::string GetAllOutputTypes()
 
 static RPCHelpMan decodescript()
 {
-    return RPCHelpMan{"decodescript",
-                "\nDecode a hex-encoded script.\n",
-                {
-                    {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "the hex-encoded script"},
-                },
-                RPCResult{
-                    RPCResult::Type::OBJ, "", "",
-                    {
-                        {RPCResult::Type::STR, "asm", "Script public key"},
-                        {RPCResult::Type::STR, "type", "The output type (e.g. "+GetAllOutputTypes()+")"},
-                        {RPCResult::Type::STR, "address", /* optional */ true, "The Bitcoin address (only if a well-defined address exists)"},
-                        {RPCResult::Type::STR, "p2sh", /* optional */ true, "address of P2SH script wrapping this redeem script (not returned if the script is already a P2SH)"},
-                        {RPCResult::Type::OBJ, "segwit", /* optional */ true, "Result of a witness script public key wrapping this redeem script (not returned if the script is a P2SH or witness)",
-                        {
-                            {RPCResult::Type::STR, "asm", "String representation of the script public key"},
-                            {RPCResult::Type::STR_HEX, "hex", "Hex string of the script public key"},
-                            {RPCResult::Type::STR, "type", "The type of the script public key (e.g. witness_v0_keyhash or witness_v0_scripthash)"},
-                            {RPCResult::Type::STR, "address", /* optional */ true, "The Bitcoin address (only if a well-defined address exists)"},
-                            {RPCResult::Type::STR, "p2sh-segwit", "address of the P2SH script wrapping this witness redeem script"},
-                        }},
-                    }
-                },
-                RPCExamples{
-                    HelpExampleCli("decodescript", "\"hexstring\"")
-            + HelpExampleRpc("decodescript", "\"hexstring\"")
-                },
+    return RPCHelpMan{
+        "decodescript",
+        "\nDecode a hex-encoded script.\n",
+        {
+            {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "the hex-encoded script"},
+        },
+        RPCResult{
+            RPCResult::Type::OBJ, "", "",
+            {
+                {RPCResult::Type::STR, "asm", "Script public key"},
+                {RPCResult::Type::STR, "type", "The output type (e.g. " + GetAllOutputTypes() + ")"},
+                {RPCResult::Type::STR, "address", /* optional */ true, "The Bitcoin address (only if a well-defined address exists)"},
+                {RPCResult::Type::STR, "p2sh", /* optional */ true, "address of P2SH script wrapping this redeem script (not returned if the script is already a P2SH)"},
+                {RPCResult::Type::OBJ, "segwit", /* optional */ true, "Result of a witness script public key wrapping this redeem script (not returned if the script is a P2SH or witness)",
+                 {
+                     {RPCResult::Type::STR, "asm", "String representation of the script public key"},
+                     {RPCResult::Type::STR_HEX, "hex", "Hex string of the script public key"},
+                     {RPCResult::Type::STR, "type", "The type of the script public key (e.g. witness_v0_keyhash or witness_v0_scripthash)"},
+                     {RPCResult::Type::STR, "address", /* optional */ true, "The Bitcoin address (only if a well-defined address exists)"},
+                     {RPCResult::Type::STR, "p2sh-segwit", "address of the P2SH script wrapping this witness redeem script"},
+                 }},
+            },
+        },
+        RPCExamples{
+            HelpExampleCli("decodescript", "\"hexstring\"")
+          + HelpExampleRpc("decodescript", "\"hexstring\"")
+        },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
     RPCTypeCheck(request.params, {UniValue::VSTR});
@@ -580,18 +581,16 @@ static RPCHelpMan decodescript()
     }
     ScriptPubKeyToUniv(script, r, /* include_hex */ false);
 
-    UniValue type;
-    type = find_value(r, "type");
+    std::vector<std::vector<unsigned char>> solutions_data;
+    const TxoutType which_type{Solver(script, solutions_data)};
 
-    if (type.isStr() && type.get_str() != "scripthash") {
+    if (which_type != TxoutType::SCRIPTHASH) {
         // P2SH cannot be wrapped in a P2SH. If this script is already a P2SH,
         // don't return the address for a P2SH of the P2SH.
         r.pushKV("p2sh", EncodeDestination(ScriptHash(script)));
         // P2SH and witness programs cannot be wrapped in P2WSH, if this script
         // is a witness program, don't return addresses for a segwit programs.
-        if (type.get_str() == "pubkey" || type.get_str() == "pubkeyhash" || type.get_str() == "multisig" || type.get_str() == "nonstandard") {
-            std::vector<std::vector<unsigned char>> solutions_data;
-            TxoutType which_type = Solver(script, solutions_data);
+        if (which_type == TxoutType::PUBKEY || which_type == TxoutType::PUBKEYHASH || which_type == TxoutType::MULTISIG || which_type == TxoutType::NONSTANDARD) {
             // Uncompressed pubkeys cannot be used with segwit checksigs.
             // If the script contains an uncompressed pubkey, skip encoding of a segwit program.
             if ((which_type == TxoutType::PUBKEY) || (which_type == TxoutType::MULTISIG)) {