From df08a626e0440457ae0d1966439fd956c27ae2fe Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Mon, 20 Oct 2014 02:10:03 +0000
Subject: [PATCH] TestBlockValidity function for CBlock proposals (used by
 CreateNewBlock)

---
 src/main.cpp  | 26 +++++++++++++++++++++++++-
 src/main.h    |  5 ++++-
 src/miner.cpp | 17 ++---------------
 3 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 2781c6f3f..fda71a365 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1593,7 +1593,7 @@ static int64_t nTimeIndex = 0;
 static int64_t nTimeCallbacks = 0;
 static int64_t nTimeTotal = 0;
 
-bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool fJustCheck)
+bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool fJustCheck)
 {
     AssertLockHeld(cs_main);
     // Check it again in case a previous version let a bad block in
@@ -2573,6 +2573,30 @@ bool ProcessNewBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDis
     return true;
 }
 
+bool TestBlockValidity(CValidationState &state, const CBlock& block, CBlockIndex * const pindexPrev, bool fCheckPOW, bool fCheckMerkleRoot)
+{
+    AssertLockHeld(cs_main);
+    assert(pindexPrev == chainActive.Tip());
+
+    CCoinsViewCache viewNew(pcoinsTip);
+    CBlockIndex indexDummy(block);
+    indexDummy.pprev = pindexPrev;
+    indexDummy.nHeight = pindexPrev->nHeight + 1;
+
+    // NOTE: CheckBlockHeader is called by CheckBlock
+    if (!ContextualCheckBlockHeader(block, state, pindexPrev))
+        return false;
+    if (!CheckBlock(block, state, fCheckPOW, fCheckMerkleRoot))
+        return false;
+    if (!ContextualCheckBlock(block, state, pindexPrev))
+        return false;
+    if (!ConnectBlock(block, state, &indexDummy, viewNew, true))
+        return false;
+    assert(state.IsValid());
+
+    return true;
+}
+
 
 
 
diff --git a/src/main.h b/src/main.h
index 6e684be8c..b49f0a06e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -457,7 +457,7 @@ bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex);
 bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool* pfClean = NULL);
 
 // Apply the effects of this block (with given index) on the UTXO set represented by coins
-bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool fJustCheck = false);
+bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool fJustCheck = false);
 
 // Context-independent validity checks
 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
@@ -467,6 +467,9 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = t
 bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex *pindexPrev);
 bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex *pindexPrev);
 
+// Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held)
+bool TestBlockValidity(CValidationState &state, const CBlock& block, CBlockIndex *pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
+
 // Store block on disk
 // if dbp is provided, the file is known to already reside on disk
 bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex **pindex, CDiskBlockPos* dbp = NULL);
diff --git a/src/miner.cpp b/src/miner.cpp
index d7ecd5e40..200498d10 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -321,22 +321,9 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
         pblock->nNonce         = 0;
         pblocktemplate->vTxSigOps[0] = GetLegacySigOpCount(pblock->vtx[0]);
 
-        CBlockIndex indexDummy(*pblock);
-        indexDummy.pprev = pindexPrev;
-        indexDummy.nHeight = pindexPrev->nHeight + 1;
-        CCoinsViewCache viewNew(pcoinsTip);
         CValidationState state;
-        // NOTE: CheckBlockHeader is called by CheckBlock
-        if (!ContextualCheckBlockHeader(*pblock, state, pindexPrev))
-            throw std::runtime_error("CreateNewBlock() : ContextualCheckBlockHeader failed");
-        if (!CheckBlock(*pblock, state, false, false))
-            throw std::runtime_error("CreateNewBlock() : CheckBlock failed");
-        if (!ContextualCheckBlock(*pblock, state, pindexPrev))
-            throw std::runtime_error("CreateNewBlock() : ContextualCheckBlock failed");
-        if (!ConnectBlock(*pblock, state, &indexDummy, viewNew, true))
-            throw std::runtime_error("CreateNewBlock() : ConnectBlock failed");
-        if (!state.IsValid())
-            throw std::runtime_error("CreateNewBlock() : State is not valid");
+        if (!TestBlockValidity(state, *pblock, pindexPrev, false, false))
+            throw std::runtime_error("CreateNewBlock() : TestBlockValidity failed");
     }
 
     return pblocktemplate.release();