Fixed errors found in unit tests.

src/main/java/org/qortal/api/resource/BlocksResource.java

@@ -761,7 +761,7 @@ public class BlocksResource {
 
 			// Use the latest X blocks if only a count is specified
 			if (startHeight == null && endHeight == null && count != null) {
-				BlockData chainTip = Controller.getInstance().getChainTip();
+				BlockData chainTip = repository.getBlockRepository().getLastBlock();
 				startHeight = chainTip.getHeight() - count;
 				endHeight = chainTip.getHeight();
 			}

src/main/java/org/qortal/repository/BlockArchiveReader.java

@@ -47,21 +47,23 @@ public class BlockArchiveReader {
         String[] files = archiveDirFile.list();
         Map<String, Triple<Integer, Integer, Integer>> map = new HashMap<>();
 
-        for (String file : files) {
-            Path filePath = Paths.get(file);
-            String filename = filePath.getFileName().toString();
-
-            // Parse the filename
-            if (filename == null || !filename.contains("-") || !filename.contains(".")) {
-                // Not a usable file
-                continue;
+        if (files != null) {
+            for (String file : files) {
+                Path filePath = Paths.get(file);
+                String filename = filePath.getFileName().toString();
+
+                // Parse the filename
+                if (filename == null || !filename.contains("-") || !filename.contains(".")) {
+                    // Not a usable file
+                    continue;
+                }
+                // Remove the extension and split into two parts
+                String[] parts = filename.substring(0, filename.lastIndexOf('.')).split("-");
+                Integer startHeight = Integer.parseInt(parts[0]);
+                Integer endHeight = Integer.parseInt(parts[1]);
+                Integer range = endHeight - startHeight;
+                map.put(filename, new Triple(startHeight, endHeight, range));
             }
-            // Remove the extension and split into two parts
-            String[] parts = filename.substring(0, filename.lastIndexOf('.')).split("-");
-            Integer startHeight = Integer.parseInt(parts[0]);
-            Integer endHeight = Integer.parseInt(parts[1]);
-            Integer range = endHeight - startHeight;
-            map.put(filename, new Triple(startHeight, endHeight, range));
         }
         this.fileListCache = map;
     }