Add RescanFromTime method and use from rpcdump

No change in behavior.

src/wallet/rpcdump.cpp

@@ -149,7 +149,7 @@ UniValue importprivkey(const JSONRPCRequest& request)
         pwallet->UpdateTimeFirstKey(1);
 
         if (fRescan) {
-            pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
+            pwallet->RescanFromTime(TIMESTAMP_MIN, true /* update */);
         }
     }
 
@@ -279,7 +279,7 @@ UniValue importaddress(const JSONRPCRequest& request)
 
     if (fRescan)
     {
-        pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
+        pwallet->RescanFromTime(TIMESTAMP_MIN, true /* update */);
         pwallet->ReacceptWalletTransactions();
     }
 
@@ -437,7 +437,7 @@ UniValue importpubkey(const JSONRPCRequest& request)
 
     if (fRescan)
     {
-        pwallet->ScanForWalletTransactions(chainActive.Genesis(), true);
+        pwallet->RescanFromTime(TIMESTAMP_MIN, true /* update */);
         pwallet->ReacceptWalletTransactions();
     }
 
@@ -537,11 +537,7 @@ UniValue importwallet(const JSONRPCRequest& request)
     file.close();
     pwallet->ShowProgress("", 100); // hide progress dialog in GUI
     pwallet->UpdateTimeFirstKey(nTimeBegin);
-
-    CBlockIndex *pindex = chainActive.FindEarliestAtLeast(nTimeBegin - TIMESTAMP_WINDOW);
-
-    LogPrintf("Rescanning last %i blocks\n", pindex ? chainActive.Height() - pindex->nHeight + 1 : 0);
-    pwallet->ScanForWalletTransactions(pindex);
+    pwallet->RescanFromTime(nTimeBegin - TIMESTAMP_WINDOW, false /* update */);
     pwallet->MarkDirty();
 
     if (!fGood)
@@ -1117,14 +1113,10 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
     }
 
     if (fRescan && fRunScan && requests.size()) {
-        CBlockIndex* pindex = nLowestTimestamp > minimumTimestamp ? chainActive.FindEarliestAtLeast(std::max<int64_t>(nLowestTimestamp - TIMESTAMP_WINDOW, 0)) : chainActive.Genesis();
-        CBlockIndex* scanFailed = nullptr;
-        if (pindex) {
-            scanFailed = pwallet->ScanForWalletTransactions(pindex, true);
+        int64_t scannedTime = pwallet->RescanFromTime(nLowestTimestamp - TIMESTAMP_WINDOW, true /* update */);
         pwallet->ReacceptWalletTransactions();
-        }
 
-        if (scanFailed) {
+        if (scannedTime > nLowestTimestamp - TIMESTAMP_WINDOW) {
             std::vector<UniValue> results = response.getValues();
             response.clear();
             response.setArray();
@@ -1134,7 +1126,7 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
                 // range, or if the import result already has an error set, let
                 // the result stand unmodified. Otherwise replace the result
                 // with an error message.
-                if (GetImportTimestamp(request, now) - TIMESTAMP_WINDOW > scanFailed->GetBlockTimeMax() || results.at(i).exists("error")) {
+                if (scannedTime <= GetImportTimestamp(request, now) - TIMESTAMP_WINDOW || results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
                     UniValue result = UniValue(UniValue::VOBJ);
@@ -1150,7 +1142,7 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
                                       "caused by pruning or data corruption (see bitcoind log for details) and could "
                                       "be dealt with by downloading and rescanning the relevant blocks (see -reindex "
                                       "and -rescan options).",
-                                GetImportTimestamp(request, now), scanFailed->GetBlockTimeMax(), TIMESTAMP_WINDOW)));
+                                GetImportTimestamp(request, now), scannedTime - 1, TIMESTAMP_WINDOW)));
                     response.push_back(std::move(result));
                 }
                 ++i;

src/wallet/wallet.cpp

@@ -221,6 +221,10 @@ bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigne
     return CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret);
 }
 
+/**
+ * Update wallet first key creation time. This should be called whenever keys
+ * are added to the wallet, with the oldest key creation time.
+ */
 void CWallet::UpdateTimeFirstKey(int64_t nCreateTime)
 {
     AssertLockHeld(cs_wallet);
@@ -1458,6 +1462,34 @@ void CWalletTx::GetAmounts(std::list<COutputEntry>& listReceived,
 
 }
 
+/**
+ * Scan active chain for relevant transactions after importing keys. This should
+ * be called whenever new keys are added to the wallet, with the oldest key
+ * creation time minus TIMESTAMP_WINDOW.
+ *
+ * @return Earliest timestamp that could be successfully scanned from. Timestamp
+ * returned may be higher than startTime if some blocks could not be read.
+ */
+int64_t CWallet::RescanFromTime(int64_t startTime, bool update)
+{
+    AssertLockHeld(cs_main);
+    AssertLockHeld(cs_wallet);
+
+    // Find starting block. May be null if nCreateTime is greater than the
+    // highest blockchain timestamp, in which case there is nothing that needs
+    // to be scanned.
+    CBlockIndex* const startBlock = chainActive.FindEarliestAtLeast(startTime);
+    LogPrintf("%s: Rescanning last %i blocks\n", __func__, startBlock ? chainActive.Height() - startBlock->nHeight + 1 : 0);
+
+    if (startBlock) {
+        const CBlockIndex* const failedBlock = ScanForWalletTransactions(startBlock, update);
+        if (failedBlock) {
+            return failedBlock->GetBlockTimeMax() + 1;
+        }
+    }
+    return startTime;
+}
+
 /**
  * Scan the block chain (starting in pindexStart) for transactions
  * from or to us. If fUpdate is true, found transactions that already

src/wallet/wallet.h

@@ -67,6 +67,8 @@ static const bool DEFAULT_USE_HD_WALLET = true;
 
 extern const char * DEFAULT_WALLET_DAT;
 
+static const int64_t TIMESTAMP_MIN = 0;
+
 class CBlockIndex;
 class CCoinControl;
 class COutput;
@@ -918,6 +920,7 @@ public:
     void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) override;
     void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
     bool AddToWalletIfInvolvingMe(const CTransactionRef& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate);
+    int64_t RescanFromTime(int64_t startTime, bool update);
     CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate = false);
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) override;