wallet: bugfix, load wallet with an unknown descriptor cause fatal error

If the descriptor entry is unrecognized/corrupt, the unserialization fails and
`LoadWallet` instead of stop there and return the error, continues reading all
the db records. As other records tied to the unrecognized/corrupted descriptor
are scanned, a fatal error is thrown.

Author: furszy

src/wallet/wallet.cpp

@@ -2819,8 +2819,12 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
             warnings.push_back(strprintf(_("Error reading %s! Transaction data may be missing or incorrect."
                                            " Rescanning wallet."), walletFile));
             rescan_required = true;
-        }
-        else {
+        } else if (nLoadWalletRet == DBErrors::UNKNOWN_DESCRIPTOR) {
+            error = strprintf(_("Unrecognized descriptor found. Loading wallet %s\n\n"
+                                "The wallet might had been created on a newer version.\n"
+                                "Please try running the latest software version.\n"), walletFile);
+            return nullptr;
+        } else {
             error = strprintf(_("Error loading %s"), walletFile);
             return nullptr;
         }

src/wallet/walletdb.cpp

@@ -314,6 +314,7 @@ class CWalletScanState {
     std::map<std::pair<uint256, CKeyID>, std::pair<CPubKey, std::vector<unsigned char>>> m_descriptor_crypt_keys;
     std::map<uint160, CHDChain> m_hd_chains;
     bool tx_corrupt{false};
+    bool descriptor_unknown{false};
 
     CWalletScanState() = default;
 };
@@ -627,7 +628,13 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             uint256 id;
             ssKey >> id;
             WalletDescriptor desc;
-            ssValue >> desc;
+            try {
+                ssValue >> desc;
+            } catch (const std::ios_base::failure& e) {
+                strErr = e.what();
+                wss.descriptor_unknown = true;
+                return false;
+            }
             if (wss.m_descriptor_caches.count(id) == 0) {
                 wss.m_descriptor_caches[id] = DescriptorCache();
             }
@@ -767,6 +774,12 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
     DBErrors result = DBErrors::LOAD_OK;
 
     LOCK(pwallet->cs_wallet);
+
+    // Last client version to open this wallet
+    int last_client = CLIENT_VERSION;
+    bool has_last_client = m_batch->Read(DBKeys::VERSION, last_client);
+    pwallet->WalletLogPrintf("Wallet file version = %d, last client version = %d\n", pwallet->GetVersion(), last_client);
+
     try {
         int nMinVersion = 0;
         if (m_batch->Read(DBKeys::MINVERSION, nMinVersion)) {
@@ -832,6 +845,13 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
                     // Set tx_corrupt back to false so that the error is only printed once (per corrupt tx)
                     wss.tx_corrupt = false;
                     result = DBErrors::CORRUPT;
+                } else if (wss.descriptor_unknown) {
+                    strErr = strprintf("Error: Unrecognized descriptor found in wallet %s. ", pwallet->GetName());
+                    strErr += (last_client > CLIENT_VERSION) ? "The wallet might had been created on a newer version. " :
+                            "The database might be corrupted or the software version is not compatible with one of your wallet descriptors. ";
+                    strErr += "Please try running the latest software version";
+                    pwallet->WalletLogPrintf("%s\n", strErr);
+                    return DBErrors::UNKNOWN_DESCRIPTOR;
                 } else {
                     // Leave other errors alone, if we try to fix them we might make things worse.
                     fNoncriticalErrors = true; // ... but do warn the user there is something wrong.
@@ -884,11 +904,6 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
     if (result != DBErrors::LOAD_OK)
         return result;
 
-    // Last client version to open this wallet
-    int last_client = CLIENT_VERSION;
-    bool has_last_client = m_batch->Read(DBKeys::VERSION, last_client);
-    pwallet->WalletLogPrintf("Wallet file version = %d, last client version = %d\n", pwallet->GetVersion(), last_client);
-
     pwallet->WalletLogPrintf("Keys: %u plaintext, %u encrypted, %u w/ metadata, %u total. Unknown wallet records: %u\n",
            wss.nKeys, wss.nCKeys, wss.nKeyMeta, wss.nKeys + wss.nCKeys, wss.m_unknown_records);
 

src/wallet/walletdb.h

@@ -51,7 +51,8 @@ enum class DBErrors
     EXTERNAL_SIGNER_SUPPORT_REQUIRED,
     LOAD_FAIL,
     NEED_REWRITE,
-    NEED_RESCAN
+    NEED_RESCAN,
+    UNKNOWN_DESCRIPTOR
 };
 
 namespace DBKeys {