Remove ReadVersion and WriteVersion

The "version" record that these functions read and write are not
used anywhere in the code except for one place. There is no reason
to expose these functions publicly. Furthermore, this avoids potential
confusion as developers may mistake these functions for actually
reading and writing the wallet version when they do not.

src/wallet/db.cpp

@@ -587,7 +587,7 @@ BerkeleyBatch::BerkeleyBatch(BerkeleyDatabase& database, const char* pszMode, bo
             if (fCreate && !Exists(std::string("version"))) {
                 bool fTmp = fReadOnly;
                 fReadOnly = false;
-                WriteVersion(CLIENT_VERSION);
+                Write(std::string("version"), CLIENT_VERSION);
                 fReadOnly = fTmp;
             }
         }

src/wallet/db.h

@@ -396,17 +396,6 @@ public:
         return (ret == 0);
     }
 
-    bool ReadVersion(int& nVersion)
-    {
-        nVersion = 0;
-        return Read(std::string("version"), nVersion);
-    }
-
-    bool WriteVersion(int nVersion)
-    {
-        return Write(std::string("version"), nVersion);
-    }
-
     bool static Rewrite(BerkeleyDatabase& database, const char* pszSkip = nullptr);
 };
 

src/wallet/walletdb.cpp

@@ -507,7 +507,7 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
 
     // Last client version to open this wallet, was previously the file version number
     int last_client = CLIENT_VERSION;
-    ReadVersion(last_client);
+    m_batch.Read(std::string("version"), last_client);
 
     int wallet_version = pwallet->GetVersion();
     pwallet->WalletLogPrintf("Wallet File Version = %d\n", wallet_version > 0 ? wallet_version : last_client);
@@ -527,7 +527,7 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
         return DBErrors::NEED_REWRITE;
 
     if (last_client < CLIENT_VERSION) // Update
-        WriteVersion(CLIENT_VERSION);
+        m_batch.Write(std::string("version"), CLIENT_VERSION);
 
     if (wss.fAnyUnordered)
         result = pwallet->ReorderTransactions();
@@ -770,13 +770,3 @@ bool WalletBatch::TxnAbort()
 {
     return m_batch.TxnAbort();
 }
-
-bool WalletBatch::ReadVersion(int& nVersion)
-{
-    return m_batch.ReadVersion(nVersion);
-}
-
-bool WalletBatch::WriteVersion(int nVersion)
-{
-    return m_batch.WriteVersion(nVersion);
-}

src/wallet/walletdb.h

@@ -241,10 +241,6 @@ public:
     bool TxnCommit();
     //! Abort current transaction
     bool TxnAbort();
-    //! Read wallet version
-    bool ReadVersion(int& nVersion);
-    //! Write wallet version
-    bool WriteVersion(int nVersion);
 private:
     BerkeleyBatch m_batch;
     WalletDatabase& m_database;