Merge #13079: Fix rescanblockchain rpc to properly report progress

16be13345 Fix rescanblockchain rpc to property report progress (Ben Woosley)

Pull request description:

  Previously it assumed tip in all cases. This also extracts a RescanVerificationProgress helper object whose role is to manage reporting, in order to simplify ScanForWalletTransactions - more lines in total, but much simpler to follow the core logic.

Tree-SHA512: 5ebed0c56fae4ccfe613ff1d7082cb6da5a86635a8993ed3af70b500a4ea43074121aea9219b2f0321fbfeb7efcb964bdc2199297a64ca0fa85d9d07aa637d40

src/wallet/wallet.cpp

@@ -1745,23 +1745,27 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
         fAbortRescan = false;
         ShowProgress(_("Rescanning..."), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup
         CBlockIndex* tip = nullptr;
-        double dProgressStart;
-        double dProgressTip;
+        double progress_begin;
+        double progress_end;
         {
             LOCK(cs_main);
-            tip = chainActive.Tip();
-            dProgressStart = GuessVerificationProgress(chainParams.TxData(), pindex);
-            dProgressTip = GuessVerificationProgress(chainParams.TxData(), tip);
+            progress_begin = GuessVerificationProgress(chainParams.TxData(), pindex);
+            if (pindexStop == nullptr) {
+                tip = chainActive.Tip();
+                progress_end = GuessVerificationProgress(chainParams.TxData(), tip);
+            } else {
+                progress_end = GuessVerificationProgress(chainParams.TxData(), pindexStop);
+            }
         }
-        double gvp = dProgressStart;
+        double progress_current = progress_begin;
         while (pindex && !fAbortRescan && !ShutdownRequested())
         {
-            if (pindex->nHeight % 100 == 0 && dProgressTip - dProgressStart > 0.0) {
-                ShowProgress(_("Rescanning..."), std::max(1, std::min(99, (int)((gvp - dProgressStart) / (dProgressTip - dProgressStart) * 100))));
+            if (pindex->nHeight % 100 == 0 && progress_end - progress_begin > 0.0) {
+                ShowProgress(_("Rescanning..."), std::max(1, std::min(99, (int)((progress_current - progress_begin) / (progress_end - progress_begin) * 100))));
             }
             if (GetTime() >= nNow + 60) {
                 nNow = GetTime();
-                LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, gvp);
+                LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, progress_current);
             }
 
             CBlock block;
@@ -1785,18 +1789,18 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
             {
                 LOCK(cs_main);
                 pindex = chainActive.Next(pindex);
-                gvp = GuessVerificationProgress(chainParams.TxData(), pindex);
-                if (tip != chainActive.Tip()) {
+                progress_current = GuessVerificationProgress(chainParams.TxData(), pindex);
+                if (pindexStop == nullptr && tip != chainActive.Tip()) {
                     tip = chainActive.Tip();
                     // in case the tip has changed, update progress max
-                    dProgressTip = GuessVerificationProgress(chainParams.TxData(), tip);
+                    progress_end = GuessVerificationProgress(chainParams.TxData(), tip);
                 }
             }
         }
         if (pindex && fAbortRescan) {
-            LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, gvp);
+            LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, progress_current);
         } else if (pindex && ShutdownRequested()) {
-            LogPrintf("Rescan interrupted by shutdown request at block %d. Progress=%f\n", pindex->nHeight, gvp);
+            LogPrintf("Rescan interrupted by shutdown request at block %d. Progress=%f\n", pindex->nHeight, progress_current);
         }
         ShowProgress(_("Rescanning..."), 100); // hide progress dialog in GUI
     }