1 files changed, 52 insertions, 3 deletions

diff --git a/src/main.h b/src/main.h
index d34778d12f..50e0004585 100644
--- a/src/main.h
+++ b/src/main.h
@@ -128,6 +128,8 @@ FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
 bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos *dbp = NULL);
 /** Load the block tree and coins database from disk */
 bool LoadBlockIndex();
+/** Verify consistency of the block and coin databases */
+bool VerifyDB();
 /** Print the loaded block tree */
 void PrintBlockTree();
 /** Find a block by height in the currently-connected chain */
@@ -748,7 +750,7 @@ public:
         READWRITE(vtxundo);
     )
 
-    bool WriteToDisk(CDiskBlockPos &pos)
+    bool WriteToDisk(CDiskBlockPos &pos, const uint256 &hashBlock)
     {
         // Open history file to append
         CAutoFile fileout = CAutoFile(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
@@ -766,6 +768,12 @@ public:
         pos.nPos = (unsigned int)fileOutPos;
         fileout << *this;
 
+        // calculate & write checksum
+        CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
+        hasher << hashBlock;
+        hasher << *this;
+        fileout << hasher.GetHash();
+
         // Flush stdio buffers and commit to disk before returning
         fflush(fileout);
         if (!IsInitialBlockDownload())
@@ -773,6 +781,44 @@ public:
 
         return true;
     }
+
+    bool ReadFromDisk(const CDiskBlockPos &pos, const uint256 &hashBlock)
+    {
+        // Open history file to read
+        CAutoFile filein = CAutoFile(OpenUndoFile(pos, true), SER_DISK, CLIENT_VERSION);
+        if (!filein)
+            return error("CBlockUndo::ReadFromDisk() : OpenBlockFile failed");
+
+        // Read block
+        uint256 hashChecksum;
+        try {
+            filein >> *this;
+        }
+        catch (std::exception &e) {
+            return error("%s() : deserialize or I/O error", __PRETTY_FUNCTION__);
+        }
+
+        // for compatibility with pre-release code that didn't write checksums to undo data
+        // TODO: replace by a simply 'filein >> hashChecksum' in the above try block
+        try {
+            filein >> hashChecksum;
+        } catch (std::exception &e) {
+            hashChecksum = 0;
+        }
+        uint32_t hashInit = hashChecksum.Get64(0) & 0xFFFFFFFFUL;
+        if (hashChecksum == 0 || memcmp(&hashInit, pchMessageStart, 4) == 0)
+            return true;
+
+        // Verify checksum
+        CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
+        hasher << hashBlock;
+        hasher << *this;
+        if (hashChecksum != hasher.GetHash())
+            return error("CBlockUndo::ReadFromDisk() : checksum mismatch");
+
+        return true;
+    }
+
 };
 
 /** pruned version of CTransaction: only retains metadata and unspent transaction outputs
@@ -1307,8 +1353,11 @@ public:
     }
 
 
-    // Undo the effects of this block (with given index) on the UTXO set represented by coins
-    bool DisconnectBlock(CBlockIndex *pindex, CCoinsViewCache &coins);
+    /** Undo the effects of this block (with given index) on the UTXO set represented by coins.
+     *  In case pfClean is provided, operation will try to be tolerant about errors, and *pfClean
+     *  will be true if no problems were found. Otherwise, the return value will be false in case
+     *  of problems. Note that in any case, coins may be modified. */
+    bool DisconnectBlock(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(CBlockIndex *pindex, CCoinsViewCache &coins, bool fJustCheck=false);