From 9ca9fa595fe796da8e1809a7fa3376744fd621f6 Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Sun, 7 Jul 2013 16:11:22 +0000
Subject: [PATCH] Replace "%p" with the previous block hash in CoinbaserCmd

---
 config.py.example | 2 ++
 eloipool.py       | 4 +++-
 merklemaker.py    | 4 ++--
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/config.py.example b/config.py.example
index cd1ea7c..f69811b 100644
--- a/config.py.example
+++ b/config.py.example
@@ -59,6 +59,8 @@ IdleSleepTime = 0.1
 TrackerAddr = 'mrsP7M31efGkQHXb7nRiWLDjfV2M8oakf2'  # testnet
 
 # Coinbaser command to control reward delegation
+# %d is replaced with the total value of the block reward (in satoshis)
+# %p is replaced with the previous block hash in hexadecimal
 # NOTE: This example donates 1% of block rewards to Luke-Jr for Eloipool development
 CoinbaserCmd = 'echo -e "1\\n$((%d / 100))\\n1579aXhdwvKZEMrAKoCZhzGuqMa8EonuXU"'
 
diff --git a/eloipool.py b/eloipool.py
index 6ddd358..3a90c83 100755
--- a/eloipool.py
+++ b/eloipool.py
@@ -90,11 +90,12 @@ except:
 from bitcoin.script import BitcoinScript
 from bitcoin.txn import Txn
 from base58 import b58decode
+from binascii import b2a_hex
 from struct import pack
 import subprocess
 from time import time
 
-def makeCoinbaseTxn(coinbaseValue, useCoinbaser = True):
+def makeCoinbaseTxn(coinbaseValue, useCoinbaser = True, prevBlockHex = None):
 	txn = Txn.new()
 	
 	if useCoinbaser and hasattr(config, 'CoinbaserCmd') and config.CoinbaserCmd:
@@ -102,6 +103,7 @@ def makeCoinbaseTxn(coinbaseValue, useCoinbaser = True):
 		try:
 			cmd = config.CoinbaserCmd
 			cmd = cmd.replace('%d', str(coinbaseValue))
+			cmd = cmd.replace('%p', prevBlockHex or '""')
 			p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE)
 			nout = int(p.stdout.readline())
 			for i in range(nout):
diff --git a/merklemaker.py b/merklemaker.py
index 0b54709..5f8401d 100644
--- a/merklemaker.py
+++ b/merklemaker.py
@@ -375,7 +375,7 @@ class merkleMaker(threading.Thread):
 		
 		self._makeBlockSafe(MP, txnlist, txninfo)
 		
-		cbtxn = self.makeCoinbaseTxn(MP['coinbasevalue'])
+		cbtxn = self.makeCoinbaseTxn(MP['coinbasevalue'], prevBlockHex = MP['previousblockhash'])
 		cbtxn.setCoinbase(b'\0\0')
 		cbtxn.assemble()
 		txnlist.insert(0, cbtxn.data)
@@ -788,7 +788,7 @@ def _test():
 	txninfo[2]['fee'] = 0
 	assert MBS(1) == (MP, txnlist, txninfo)
 	# _ProcessGBT tests
-	def makeCoinbaseTxn(coinbaseValue, useCoinbaser = True):
+	def makeCoinbaseTxn(coinbaseValue, useCoinbaser = True, prevBlockHex = None):
 		txn = Txn.new()
 		txn.addOutput(coinbaseValue, b'')
 		return txn
-- 
2.1.4