Self check after the last peer is removed

src/main.cpp

@@ -338,6 +338,13 @@ void FinalizeNode(NodeId nodeid) {
     assert(nPeersWithValidatedDownloads >= 0);
 
     mapNodeState.erase(nodeid);
+
+    if (mapNodeState.empty()) {
+        // Do a consistency check after the last peer is removed.
+        assert(mapBlocksInFlight.empty());
+        assert(nPreferredDownload == 0);
+        assert(nPeersWithValidatedDownloads == 0);
+    }
 }
 
 // Requires cs_main.