Merge pull request #445 from gandrewstone/dev_validateblocktemplate

add validateblocktemplate RPC call

doc/miner.md

@@ -179,3 +179,15 @@ When you restart bitcoind, the memory pool starts empty.  If a block is found qu
 `bitcoin-cli addnode <new node's IP:port> onetry`
 `bitcoin-cli pushtx <new node's IP:port>`
 ```
+
+Validating unsolved blocks
+--------------------------
+
+Bitcoin Unlimited can be used to validate block templates received from other Bitcoin Unlimited releases or other bitcoin clients.  This ensures that Bitcoin Unlimited will accept the block once it is mined, allowing miners to deploy multiple clients in their mining networks.  Note that this API will return an error if the block is not built off of the chain tip seen by this client.  So it is important that the client be fully synchronized with the client that creates the block template.  You can do this by explicitly connecting them via "addnode".
+
+The block validation RPC uses the same call syntax as the "submitblock" RPC, and returns a JSONRPCException if the block validation fails.  See "qa/rpc-tests/validateblocktemplate.py" for detailed python examples.
+
+```sh
+`bitcoin-cli validateblocktemplate <hex encoded block>`
+```
+

qa/pull-tester/rpc-tests.py

@@ -160,6 +160,7 @@ def option_passed(option_without_dashes):
 #Tests
 testScripts = [ RpcTest(t) for t in [
     'bip68-112-113-p2p',
+    'validateblocktemplate',
     'parallel',
     'wallet',
     'excessive',

qa/rpc-tests/bip68-sequence.py

@@ -1,8 +1,7 @@
 #!/usr/bin/env python3
 # Copyright (c) 2014-2015 The Bitcoin Core developers
 # Copyright (c) 2015-2017 The Bitcoin Unlimited developers
-#!/usr/bin/env python3
-# Copyright (c) 2014-2016 The Bitcoin Core developers
+#
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 

qa/rpc-tests/test_framework/blocktools.py

@@ -8,7 +8,7 @@
 from .script import CScript, OP_TRUE, OP_CHECKSIG
 
 # Create a block (with regtest difficulty)
-def create_block(hashprev, coinbase, nTime=None):
+def create_block(hashprev, coinbase, nTime=None, txns=None):
     block = CBlock()
     if nTime is None:
         import time
@@ -17,7 +17,10 @@ def create_block(hashprev, coinbase, nTime=None):
         block.nTime = nTime
     block.hashPrevBlock = hashprev
     block.nBits = 0x207fffff # Will break after a difficulty adjustment...
-    block.vtx.append(coinbase)
+    if coinbase:
+        block.vtx.append(coinbase)
+    if txns:
+        block.vtx += txns
     block.hashMerkleRoot = block.calc_merkle_root()
     block.calc_sha256()
     return block
@@ -57,11 +60,15 @@ def create_coinbase(height, pubkey = None):
     return coinbase
 
 # Create a transaction with an anyone-can-spend output, that spends the
-# nth output of prevtx.
+# nth output of prevtx.  pass a single integer value to make one output,
+# or a list to create multiple outputs
 def create_transaction(prevtx, n, sig, value):
+    if not type(value) is list:
+        value = [value]
     tx = CTransaction()
     assert(n < len(prevtx.vout))
     tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff))
-    tx.vout.append(CTxOut(value, b""))
+    for v in value:
+        tx.vout.append(CTxOut(v, b""))
     tx.calc_sha256()
     return tx

qa/rpc-tests/test_framework/mininode.py

@@ -377,7 +377,7 @@ def deserialize(self, f):
 
     def serialize(self):
         r = b""
-        r += struct.pack("<q", self.nValue)
+        r += struct.pack("<q", int(self.nValue))
         r += ser_string(self.scriptPubKey)
         return r
 
@@ -535,7 +535,9 @@ def calc_merkle_root(self):
                 i2 = min(i+1, len(hashes)-1)
                 newhashes.append(hash256(hashes[i] + hashes[i2]))
             hashes = newhashes
-        return uint256_from_str(hashes[0])
+        if hashes:
+          return uint256_from_str(hashes[0])
+        return 0
 
     def is_valid(self):
         self.calc_sha256()