Merge #11237: qt: Fixing division by zero in time remaining

c8d38abd6 Refactor tipUpdate as per style guide (MeshCollider)
3b69a08c5 Fix division by zero in time remaining (MeshCollider)

Pull request description:

  Fixes https://github.com/bitcoin/bitcoin/issues/10291, https://github.com/bitcoin/bitcoin/issues/11265

  progressDelta may be 0 (or even negative according to 11265), this checks for that and prints unknown if it is, because we cannot calculate an estimate for the time remaining (would be infinite or negative).

Tree-SHA512: bc5708e5ed6e4670d008219558c5fbb25709bd99a32c98ec39bb74f94a0b7fa058f3d03389ccdd39e6723e6b5b48e34b13ceee7c051c2db631e51d8ec3e1d68c

src/qt/modaloverlay.cpp

@@ -82,36 +82,38 @@ void ModalOverlay::tipUpdate(int count, const QDateTime& blockDate, double nVeri
     blockProcessTime.push_front(qMakePair(currentDate.toMSecsSinceEpoch(), nVerificationProgress));
 
     // show progress speed if we have more then one sample
-    if (blockProcessTime.size() >= 2)
-    {
-        double progressStart = blockProcessTime[0].second;
+    if (blockProcessTime.size() >= 2) {
         double progressDelta = 0;
         double progressPerHour = 0;
         qint64 timeDelta = 0;
         qint64 remainingMSecs = 0;
         double remainingProgress = 1.0 - nVerificationProgress;
-        for (int i = 1; i < blockProcessTime.size(); i++)
-        {
+        for (int i = 1; i < blockProcessTime.size(); i++) {
             QPair<qint64, double> sample = blockProcessTime[i];
 
             // take first sample after 500 seconds or last available one
             if (sample.first < (currentDate.toMSecsSinceEpoch() - 500 * 1000) || i == blockProcessTime.size() - 1) {
-                progressDelta = progressStart-sample.second;
+                progressDelta = blockProcessTime[0].second - sample.second;
                 timeDelta = blockProcessTime[0].first - sample.first;
-                progressPerHour = progressDelta/(double)timeDelta*1000*3600;
-                remainingMSecs = remainingProgress / progressDelta * timeDelta;
+                progressPerHour = progressDelta / (double) timeDelta * 1000 * 3600;
+                remainingMSecs = (progressDelta > 0) ? remainingProgress / progressDelta * timeDelta : -1;
                 break;
             }
         }
         // show progress increase per hour
-        ui->progressIncreasePerH->setText(QString::number(progressPerHour*100, 'f', 2)+"%");
+        ui->progressIncreasePerH->setText(QString::number(progressPerHour * 100, 'f', 2)+"%");
 
         // show expected remaining time
-        ui->expectedTimeLeft->setText(GUIUtil::formatNiceTimeOffset(remainingMSecs/1000.0));
+        if(remainingMSecs >= 0) {	
+            ui->expectedTimeLeft->setText(GUIUtil::formatNiceTimeOffset(remainingMSecs / 1000.0));
+        } else {
+            ui->expectedTimeLeft->setText(QObject::tr("unknown"));
+        }
 
         static const int MAX_SAMPLES = 5000;
-        if (blockProcessTime.count() > MAX_SAMPLES)
-            blockProcessTime.remove(MAX_SAMPLES, blockProcessTime.count()-MAX_SAMPLES);
+        if (blockProcessTime.count() > MAX_SAMPLES) {
+            blockProcessTime.remove(MAX_SAMPLES, blockProcessTime.count() - MAX_SAMPLES);
+        }
     }
 
     // show the last block date