Move external block import to separate thread

src/qt/bitcoingui.cpp

@@ -473,7 +473,7 @@ void BitcoinGUI::setNumConnections(int count)
 void BitcoinGUI::setNumBlocks(int count, int nTotalBlocks)
 {
     // don't show / hide progress bar and its label if we have no connection to the network
-    if (!clientModel || clientModel->getNumConnections() == 0)
+    if (!clientModel || (clientModel->getNumConnections() == 0 && !clientModel->isImporting()))
     {
         progressBarLabel->setVisible(false);
         progressBar->setVisible(false);
@@ -491,7 +491,7 @@ void BitcoinGUI::setNumBlocks(int count, int nTotalBlocks)
 
         if (strStatusBarWarnings.isEmpty())
         {
-            progressBarLabel->setText(tr("Synchronizing with network..."));
+            progressBarLabel->setText(tr(clientModel->isImporting() ? "Importing blocks..." : "Synchronizing with network..."));
             progressBarLabel->setVisible(true);
             progressBar->setFormat(tr("~%n block(s) remaining", "", nRemainingBlocks));
             progressBar->setMaximum(nTotalBlocks);

src/qt/clientmodel.cpp

@@ -103,6 +103,11 @@ bool ClientModel::inInitialBlockDownload() const
     return IsInitialBlockDownload();
 }
 
+bool ClientModel::isImporting() const
+{
+    return fImporting;
+}
+
 int ClientModel::getNumBlocksOfPeers() const
 {
     return GetNumBlocksOfPeers();

src/qt/clientmodel.h

@@ -33,6 +33,8 @@ public:
     bool isTestNet() const;
     //! Return true if core is doing initial block download
     bool inInitialBlockDownload() const;
+    //! Return true if core is importing blocks
+    bool isImporting() const;
     //! Return conservative estimate of total number of blocks, or 0 if unknown
     int getNumBlocksOfPeers() const;
     //! Return warnings to be displayed in status bar