Handle "conflicted" transactions properly

Extend CMerkleTx::GetDepthInMainChain with the concept of
a "conflicted" transaction-- a transaction generated by the wallet
that is not in the main chain or in the mempool, and, therefore,
will likely never be confirmed.

GetDepthInMainChain() now returns -1 for conflicted transactions
(0 for unconfirmed-but-in-the-mempool, and >1 for confirmed).

This makes getbalance, getbalance '*', and listunspent all agree when there are
mutated transactions in the wallet.

Before:
 listunspent: one 49BTC output
 getbalance: 96 BTC (change counted twice)
 getbalance '*': 46 BTC (spends counted twice)

After: all agree, 49 BTC available to spend.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/main.h b/src/main.h
index 05210e5164..09250e4a3e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -423,6 +423,8 @@ public:
 /** A transaction with a merkle branch linking it to the block chain. */
 class CMerkleTx : public CTransaction
 {
+private:
+    int GetDepthInMainChainINTERNAL(CBlockIndex* &pindexRet) const;
 public:
     uint256 hashBlock;
     std::vector<uint256> vMerkleBranch;
@@ -461,9 +463,14 @@ public:
 
 
     int SetMerkleBranch(const CBlock* pblock=NULL);
+
+    // Return depth of transaction in blockchain:
+    // -1  : not in blockchain, and not in memory pool (conflicted transaction)
+    //  0  : in memory pool, waiting to be included in a block
+    // >=1 : this many blocks deep in the main chain
     int GetDepthInMainChain(CBlockIndex* &pindexRet) const;
     int GetDepthInMainChain() const { CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet); }
-    bool IsInMainChain() const { return GetDepthInMainChain() > 0; }
+    bool IsInMainChain() const { CBlockIndex *pindexRet; return GetDepthInMainChainINTERNAL(pindexRet) > 0; }
     int GetBlocksToMaturity() const;
     bool AcceptToMemoryPool(bool fLimitFree=true);
 };