[wallet] Get rid of CWalletTx default constructor

No change in behavior in the normal case. But buggy mapWallet lookups with
invalid txids will now throw exceptions instead of inserting dummy entries into
the map, and potentially causing segfaults and other failures.

This also makes it a compiler error to use the mapWallet[hash] syntax which
could create dummy entries.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 0b0880a2b..7f5f3b84b 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -265,7 +265,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
         {
             uint256 hash;
             ssKey >> hash;
-            CWalletTx wtx;
+            CWalletTx wtx(nullptr /* pwallet */, MakeTransactionRef());
             ssValue >> wtx;
             CValidationState state;
             if (!(CheckTransaction(*wtx.tx, state) && (wtx.GetHash() == hash) && state.IsValid()))
@@ -603,7 +603,7 @@ DBErrors CWalletDB::LoadWallet(CWallet* pwallet)
         pwallet->UpdateTimeFirstKey(1);
 
     for (uint256 hash : wss.vWalletUpgrade)
-        WriteTx(pwallet->mapWallet[hash]);
+        WriteTx(pwallet->mapWallet.at(hash));
 
     // Rewrite encrypted wallets of versions 0.4.0 and 0.5.0rc:
     if (wss.fIsEncrypted && (wss.nFileVersion == 40000 || wss.nFileVersion == 50000))
@@ -664,7 +664,7 @@ DBErrors CWalletDB::FindWalletTx(std::vector<uint256>& vTxHash, std::vector<CWal
                 uint256 hash;
                 ssKey >> hash;
 
-                CWalletTx wtx;
+                CWalletTx wtx(nullptr /* pwallet */, MakeTransactionRef());
                 ssValue >> wtx;
 
                 vTxHash.push_back(hash);