From 3a05f1d2ce45d5d9fbbd7b1b897f3c6e32f58720 Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jgarzik@exmulti.com>
Date: Mon, 14 May 2012 01:11:11 -0400
Subject: [PATCH] Always check return values of TxnBegin() and TxnCommit()

---
 src/bitcoinrpc.cpp |    6 ++++--
 src/main.cpp       |   12 +++++++++---
 src/wallet.cpp     |    3 ++-
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index 4426ac5..93c9b41 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -840,7 +840,8 @@ Value movecmd(const Array& params, bool fHelp)
         strComment = params[4].get_str();
 
     CWalletDB walletdb(pwalletMain->strWalletFile);
-    walletdb.TxnBegin();
+    if (!walletdb.TxnBegin())
+        throw JSONRPCError(-20, "database error");
 
     int64 nNow = GetAdjustedTime();
 
@@ -862,7 +863,8 @@ Value movecmd(const Array& params, bool fHelp)
     credit.strComment = strComment;
     walletdb.WriteAccountingEntry(credit);
 
-    walletdb.TxnCommit();
+    if (!walletdb.TxnCommit())
+        throw JSONRPCError(-20, "database error");
 
     return true;
 }
diff --git a/src/main.cpp b/src/main.cpp
index 7e4ed11..f13f616 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1496,7 +1496,9 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
 {
     uint256 hash = GetHash();
 
-    txdb.TxnBegin();
+    if (!txdb.TxnBegin())
+        return error("SetBestChain() : TxnBegin failed");
+
     if (pindexGenesisBlock == NULL && hash == hashGenesisBlock)
     {
         txdb.WriteHashBestChain(hash);
@@ -1545,7 +1547,10 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
                 printf("SetBestChain() : ReadFromDisk failed\n");
                 break;
             }
-            txdb.TxnBegin();
+            if (!txdb.TxnBegin()) {
+                printf("SetBestChain() : TxnBegin 2 failed\n");
+                break;
+            }
             // errors now are not fatal, we still did a reorganisation to a new chain in a valid way
             if (!block.SetBestChainInner(txdb, pindex))
                 break;
@@ -1603,7 +1608,8 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
     pindexNew->bnChainWork = (pindexNew->pprev ? pindexNew->pprev->bnChainWork : 0) + pindexNew->GetBlockWork();
 
     CTxDB txdb;
-    txdb.TxnBegin();
+    if (!txdb.TxnBegin())
+        return false;
     txdb.WriteBlockIndex(CDiskBlockIndex(pindexNew));
     if (!txdb.TxnCommit())
         return false;
diff --git a/src/wallet.cpp b/src/wallet.cpp
index bd17bd9..bb7f11c 100644
--- a/src/wallet.cpp
+++ b/src/wallet.cpp
@@ -234,7 +234,8 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
         if (fFileBacked)
         {
             pwalletdbEncryption = new CWalletDB(strWalletFile);
-            pwalletdbEncryption->TxnBegin();
+            if (!pwalletdbEncryption->TxnBegin())
+                return false;
             pwalletdbEncryption->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
         }
 
-- 
1.7.1