Added p2sh address to output script.

lib/bitcoin/address_to_output_script.dart

@@ -0,0 +1,25 @@
+import 'dart:typed_data';
+import 'package:bs58check/bs58check.dart' as bs58check;
+import 'package:bitcoin_flutter/src/utils/constants/op.dart';
+import 'package:bitcoin_flutter/src/utils/script.dart' as bscript;
+import 'package:bitcoin_flutter/src/address.dart';
+
+
+Uint8List p2shAddressToOutputScript(String address) {
+  final decodeBase58 = bs58check.decode(address);
+  final hash = decodeBase58.sublist(1);
+  return bscript.compile(<dynamic>[OPS['OP_HASH160'], hash, OPS['OP_EQUAL']]);
+}
+
+Uint8List addressToOutputScript(String address) {
+  try {
+    // FIXME: improve validation for p2sh addresses
+    if (address.startsWith('3')) {
+      return p2shAddressToOutputScript(address);
+    }
+
+    return Address.addressToOutputScript(address);
+  } catch (_) {
+    return Uint8List(0);
+  }
+}

lib/bitcoin/bitcoin_wallet.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'dart:convert';
+import 'package:cake_wallet/bitcoin/address_to_output_script.dart';
 import 'package:cake_wallet/bitcoin/bitcoin_mnemonic.dart';
 import 'package:mobx/mobx.dart';
 import 'package:flutter/foundation.dart';
@@ -302,7 +303,8 @@ abstract class BitcoinWalletBase extends WalletBase<BitcoinBalance> with Store {
       }
     });
 
-    txb.addOutput(transactionCredentials.address, amount);
+    txb.addOutput(
+        addressToOutputScript(transactionCredentials.address), amount);
 
     if (changeValue > 0) {
       txb.addOutput(changeAddress, changeValue);

lib/main.dart

@@ -1,4 +1,3 @@
-import 'package:cake_wallet/bitcoin/bitcoin_mnemonic.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:hive/hive.dart';