Handle TIMESTAMP_WINDOW within CWallet::RescanFromTime

This way CWallet::RescanFromTime callers don't need to subtract
TIMESTAMP_WINDOW themselves.

This is pure refactoring, there is no change in behavior.

src/wallet/rpcdump.cpp

@@ -537,7 +537,7 @@ UniValue importwallet(const JSONRPCRequest& request)
     file.close();
     pwallet->ShowProgress("", 100); // hide progress dialog in GUI
     pwallet->UpdateTimeFirstKey(nTimeBegin);
-    pwallet->RescanFromTime(nTimeBegin - TIMESTAMP_WINDOW, false /* update */);
+    pwallet->RescanFromTime(nTimeBegin, false /* update */);
     pwallet->MarkDirty();
 
     if (!fGood)
@@ -1113,10 +1113,10 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
     }
 
     if (fRescan && fRunScan && requests.size()) {
-        int64_t scannedTime = pwallet->RescanFromTime(nLowestTimestamp - TIMESTAMP_WINDOW, true /* update */);
+        int64_t scannedTime = pwallet->RescanFromTime(nLowestTimestamp, true /* update */);
         pwallet->ReacceptWalletTransactions();
 
-        if (scannedTime > nLowestTimestamp - TIMESTAMP_WINDOW) {
+        if (scannedTime > nLowestTimestamp) {
             std::vector<UniValue> results = response.getValues();
             response.clear();
             response.setArray();
@@ -1126,7 +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 (scannedTime <= GetImportTimestamp(request, now) - TIMESTAMP_WINDOW || results.at(i).exists("error")) {
+                if (scannedTime <= GetImportTimestamp(request, now) || results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
                     UniValue result = UniValue(UniValue::VOBJ);
@@ -1142,7 +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), scannedTime - 1, TIMESTAMP_WINDOW)));
+                                GetImportTimestamp(request, now), scannedTime - TIMESTAMP_WINDOW - 1, TIMESTAMP_WINDOW)));
                     response.push_back(std::move(result));
                 }
                 ++i;

src/wallet/wallet.cpp

@@ -1465,7 +1465,7 @@ 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.
+ * creation time.
  *
  * @return Earliest timestamp that could be successfully scanned from. Timestamp
  * returned will be higher than startTime if relevant blocks could not be read.
@@ -1478,13 +1478,13 @@ int64_t CWallet::RescanFromTime(int64_t startTime, bool update)
     // 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);
+    CBlockIndex* const startBlock = chainActive.FindEarliestAtLeast(startTime - TIMESTAMP_WINDOW);
     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 failedBlock->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1;
         }
     }
     return startTime;