Clean up CMerkleTx::SetMerkleBranch.

The case SetMerkleBranch(NULL) was never actually used, and thus the
involved code (loading the block from disk) can be removed and the
implementation simplified.

src/wallet.cpp

@@ -644,7 +644,7 @@ bool CWallet::AddToWalletIfInvolvingMe(const CTransaction& tx, const CBlock* pbl
             CWalletTx wtx(this,tx);
             // Get merkle branch if transaction was found in a block
             if (pblock)
-                wtx.SetMerkleBranch(pblock);
+                wtx.SetMerkleBranch(*pblock);
             return AddToWallet(wtx);
         }
     }
@@ -2195,32 +2195,19 @@ CWalletKey::CWalletKey(int64_t nExpires)
     nTimeExpires = nExpires;
 }
 
-int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
+int CMerkleTx::SetMerkleBranch(const CBlock& block)
 {
     AssertLockHeld(cs_main);
     CBlock blockTmp;
 
-    if (pblock == NULL) {
-        CCoins coins;
-        if (pcoinsTip->GetCoins(GetHash(), coins)) {
-            CBlockIndex *pindex = chainActive[coins.nHeight];
-            if (pindex) {
-                if (!ReadBlockFromDisk(blockTmp, pindex))
-                    return 0;
-                pblock = &blockTmp;
-            }
-        }
-    }
-
-    if (pblock) {
     // Update the tx's hashBlock
-        hashBlock = pblock->GetHash();
+    hashBlock = block.GetHash();
 
     // Locate the transaction
-        for (nIndex = 0; nIndex < (int)pblock->vtx.size(); nIndex++)
+    for (nIndex = 0; nIndex < (int)block.vtx.size(); nIndex++)
-            if (pblock->vtx[nIndex] == *(CTransaction*)this)
+        if (block.vtx[nIndex] == *(CTransaction*)this)
             break;
-        if (nIndex == (int)pblock->vtx.size())
+    if (nIndex == (int)block.vtx.size())
     {
         vMerkleBranch.clear();
         nIndex = -1;
@@ -2229,14 +2216,13 @@ int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
     }
 
     // Fill in merkle branch
-        vMerkleBranch = pblock->GetMerkleBranch(nIndex);
+    vMerkleBranch = block.GetMerkleBranch(nIndex);
-    }
 
     // Is the tx in a block that's in the main chain
     map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashBlock);
     if (mi == mapBlockIndex.end())
         return 0;
-    CBlockIndex* pindex = (*mi).second;
+    const CBlockIndex* pindex = (*mi).second;
     if (!pindex || !chainActive.Contains(pindex))
         return 0;
 

src/wallet.h

@@ -500,7 +500,7 @@ public:
     )
 
 
-    int SetMerkleBranch(const CBlock* pblock=NULL);
+    int SetMerkleBranch(const CBlock& block);
 
     // Return depth of transaction in blockchain:
     // -1  : not in blockchain, and not in memory pool (conflicted transaction)