handle null returned from doCtags()

Author: vladak

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/Ctags.java

@@ -47,6 +47,7 @@
 import java.util.logging.Logger;
 
 import org.apache.commons.lang3.SystemUtils;
+import org.jetbrains.annotations.Nullable;
 import org.opengrok.indexer.configuration.RuntimeEnvironment;
 import org.opengrok.indexer.index.IndexerParallelizer;
 import org.opengrok.indexer.logger.LoggerFactory;
@@ -495,6 +496,7 @@ private void addTerraformSupport(List<String> command) {
      * @throws IOException I/O exception
      * @throws InterruptedException interrupted command
      */
+    @Nullable
     public Definitions doCtags(String file) throws IOException, InterruptedException {
 
         if (file.length() < 1 || "\n".equals(file)) {

opengrok-indexer/src/main/java/org/opengrok/indexer/util/CtagsUtil.java

@@ -93,7 +93,7 @@ private static boolean canProcessFiles(String basePath) {
         Ctags ctags = new Ctags();
         try {
             Definitions definitions = ctags.doCtags(inputPath.toString());
-            if (definitions.numberOfSymbols() > 1) {
+            if (definitions != null && definitions.numberOfSymbols() > 1) {
                 return true;
             }
         } catch (IOException | InterruptedException e) {