Add support for NullData addresses (OP_RETURN)

src/rpc/util.cpp

@@ -120,6 +120,14 @@ class DescribeAddressVisitor : public boost::static_visitor<UniValue>
         obj.pushKV("witness_program", HexStr(id.program, id.program + id.length));
         return obj;
     }
+
+    UniValue operator()(const NullData& id) const
+    {
+        UniValue obj(UniValue::VOBJ);
+        obj.pushKV("isscript", false);
+        obj.pushKV("iswitness", false);
+        return obj;
+    }
 };
 
 UniValue DescribeAddress(const CTxDestination& dest)

src/script/standard.cpp

@@ -177,6 +177,11 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
     if (!Solver(scriptPubKey, whichType, vSolutions))
         return false;
 
+    if (whichType == TX_NULL_DATA) {
+        // This is data, not addresses
+        return false;
+    }
+
     if (whichType == TX_PUBKEY)
     {
         CPubKey pubKey(vSolutions[0]);
@@ -303,6 +308,16 @@ class CScriptVisitor : public boost::static_visitor<bool>
         *script << CScript::EncodeOP_N(id.version) << std::vector<unsigned char>(id.program, id.program + id.length);
         return true;
     }
+
+    bool operator()(const NullData& id) const
+    {
+        script->clear();
+        *script << OP_RETURN;
+        for (const auto& push : id.null_data) {
+            *script << push;
+        }
+        return true;
+    }
 };
 } // namespace
 

src/script/standard.h

@@ -111,6 +111,21 @@ struct WitnessUnknown
     }
 };
 
+// ELEMENTS:
+class NullData
+{
+public:
+    std::vector<std::vector<unsigned char>> null_data;
+    friend bool operator==(const NullData &a, const NullData &b) { return  true; }
+    friend bool operator<(const NullData &a, const NullData &b) { return  true; }
+
+    NullData& operator<<(std::vector<unsigned char> b)
+    {
+        null_data.push_back(b);
+        return *this;
+    }
+};
+
 /**
  * A txout script template with a specific destination. It is either:
  *  * CNoDestination: no destination set
@@ -119,9 +134,10 @@ struct WitnessUnknown
  *  * WitnessV0ScriptHash: TX_WITNESS_V0_SCRIPTHASH destination (P2WSH)
  *  * WitnessV0KeyHash: TX_WITNESS_V0_KEYHASH destination (P2WPKH)
  *  * WitnessUnknown: TX_WITNESS_UNKNOWN destination (P2W???)
+ *  * NullData: TX_NULL_DATA destination (OP_RETURN)
  *  A CTxDestination is the internal data type encoded in a bitcoin address
  */
-typedef boost::variant<CNoDestination, CKeyID, CScriptID, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown> CTxDestination;
+typedef boost::variant<CNoDestination, CKeyID, CScriptID, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown, NullData> CTxDestination;
 
 /** Check whether a CTxDestination is a CNoDestination. */
 bool IsValidDestination(const CTxDestination& dest);

src/wallet/rpcwallet.cpp

@@ -4185,6 +4185,7 @@ class DescribeWalletAddressVisitor : public boost::static_visitor<UniValue>
     }
 
     UniValue operator()(const WitnessUnknown& id) const { return UniValue(UniValue::VOBJ); }
+    UniValue operator()(const NullData& id) const { return NullUniValue; }
 };
 
 static UniValue DescribeWalletAddress(CWallet* pwallet, const CTxDestination& dest)