From 4d1e17865b09216a977e4cbfcde64362eb832356 Mon Sep 17 00:00:00 2001
From: The MMGen Project <mmgen@tuta.io>
Date: Sun, 6 Sep 2026 10:08:41 +0000
Subject: [PATCH] new BitcoinDataOutput class

---
 mmgen/proto/btc/tx/base.py        |  2 +-
 mmgen/proto/btc/tx/data_output.py | 23 +++++++++++++++++++++++
 mmgen/tx/data_output.py           |  8 ++------
 test/modtest_d/tx.py              | 17 +++++++++++------
 4 files changed, 37 insertions(+), 13 deletions(-)
 create mode 100755 mmgen/proto/btc/tx/data_output.py

diff --git a/mmgen/proto/btc/tx/base.py b/mmgen/proto/btc/tx/base.py
index c824ada0..b496c83f 100755
--- a/mmgen/proto/btc/tx/base.py
+++ b/mmgen/proto/btc/tx/base.py
@@ -18,7 +18,7 @@ from ....tx.base import Base as TxBase
 from ....obj import MMGenList, HexStr, ListItemAttr
 from ....util import msg, make_chksum_6, die, pp_fmt
 
-from ....tx.data_output import DataOutput
+from .data_output import DataOutput
 
 def data2scriptPubKey(data):
 	return '6a' + '{:02x}'.format(len(data)) + data.hex() # OP_RETURN data
diff --git a/mmgen/proto/btc/tx/data_output.py b/mmgen/proto/btc/tx/data_output.py
new file mode 100755
index 00000000..3b716387
--- /dev/null
+++ b/mmgen/proto/btc/tx/data_output.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+#
+# MMGen Wallet, a terminal-based cryptocurrency wallet
+# Copyright (C)2013-2026 The MMGen Project <mmgen@tuta.io>
+# Licensed under the GNU General Public License, Version 3:
+#   https://www.gnu.org/licenses
+# Public project repositories:
+#   https://github.com/mmgen/mmgen-wallet
+#   https://gitlab.com/mmgen/mmgen-wallet
+
+"""
+proto.btc.tx.data_output: Bitcoin data output class
+"""
+
+from ....tx.data_output import DataOutput
+
+class BitcoinDataOutput(DataOutput):
+
+	desc = 'OP_RETURN data'
+
+	@property
+	def max_len(self):
+		return self.proto.max_op_return_data_len
diff --git a/mmgen/tx/data_output.py b/mmgen/tx/data_output.py
index b155e21a..b01a35df 100755
--- a/mmgen/tx/data_output.py
+++ b/mmgen/tx/data_output.py
@@ -16,13 +16,9 @@ from ..obj import InitErrors
 
 class DataOutput(bytes, InitErrors):
 
-	desc = 'OP_RETURN data'
+	def __new__(base_cls, proto, data_spec):
 
-	@property
-	def max_len(self):
-		return self.proto.max_op_return_data_len
-
-	def __new__(cls, proto, data_spec):
+		cls = proto.base_proto_subclass(base_cls, 'tx.data_output')
 
 		assert isinstance(data_spec, str), f'{cls.desc} argument must be a string'
 
diff --git a/test/modtest_d/tx.py b/test/modtest_d/tx.py
index 55b3737e..2e97de97 100755
--- a/test/modtest_d/tx.py
+++ b/test/modtest_d/tx.py
@@ -9,6 +9,7 @@ import os
 from mmgen.tx import CompletedTX, UnsignedTX
 from mmgen.tx.file import MMGenTxFile
 from mmgen.cfg import Config
+from mmgen.protocol import init_proto
 
 from ..include.common import cfg, qmsg, vmsg, gr_uc
 
@@ -112,9 +113,13 @@ class unit_tests:
 		ut.process_bad_data(bad_data)
 		return True
 
-	def data_output(self, name, ut, desc='DataOutput class'):
-		max_len = cfg._proto.max_op_return_data_len
+	def data_output_btc(self, name, ut, desc='BitcoinDataOutput class'):
+		return self._data_output(ut, 'btc')
+
+	def _data_output(self, ut, coin):
+		proto = init_proto(cfg, coin)
 		from mmgen.tx.data_output import DataOutput
+		max_len = DataOutput(proto, 'data:abc').max_len
 		vecs = [
 			'data:=:ETH.ETH:0x86d526d6624AbC0178cF7296cD538Ecc080A95F1:0/1/0',
 			'hexdata:3d3a4554482e4554483a30783836643532366436363234416243303137'
@@ -128,11 +133,11 @@ class unit_tests:
 			'data:' + gr_uc[:24],
 		]
 
-		assert DataOutput(cfg._proto, vecs[0]) == DataOutput(cfg._proto, vecs[1])
+		assert DataOutput(proto, vecs[0]) == DataOutput(proto, vecs[1])
 
 		for vec in vecs:
-			d = DataOutput(cfg._proto, vec)
-			assert d == DataOutput(cfg._proto, repr(d)) # repr() must return a valid initializer
+			d = DataOutput(proto, vec)
+			assert d == DataOutput(proto, repr(d)) # repr() must return a valid initializer
 			assert isinstance(d, bytes)
 			assert isinstance(str(d), str)
 			vmsg('-' * 80)
@@ -156,7 +161,7 @@ class unit_tests:
 		]
 
 		def bad(n):
-			return lambda: DataOutput(cfg._proto, bad_data[n])
+			return lambda: DataOutput(proto, bad_data[n])
 
 		vmsg('-' * 80)
 		vmsg('Testing error handling:')