Program: 93735
Project: 93735
Buggy source:
private void sendDirectory(String dir,RoutingContext context){
  FileSystem fileSystem=context.vertx().fileSystem();
  HttpServerRequest request=context.request();
  fileSystem.readDir(dir,asyncResult -> {
    if (asyncResult.failed()) {
      context.fail(asyncResult.cause());
    }
 else {
      String accept=request.headers().get("String_Node_Str");
      if (accept == null) {
        accept="String_Node_Str";
      }
      if (accept.contains("String_Node_Str")) {
        String normalizedDir=dir.substring(webRoot.length());
        if (!normalizedDir.endsWith("String_Node_Str")) {
          normalizedDir+="String_Node_Str";
        }
        String file;
        StringBuilder files=new StringBuilder("String_Node_Str");
        List<String> list=asyncResult.result();
        Collections.sort(list);
        for (        String s : list) {
          file=s.substring(s.lastIndexOf('/') + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          files.append("String_Node_Str");
          files.append(normalizedDir);
          files.append(file);
          files.append("String_Node_Str");
          files.append(file);
          files.append("String_Node_Str");
          files.append(file);
          files.append("String_Node_Str");
        }
        files.append("String_Node_Str");
        int slashPos=0;
        for (int i=dir.length() - 2; i > 0; i--) {
          if (dir.charAt(i) == '/') {
            slashPos=i;
            break;
          }
        }
        String parent="String_Node_Str" + dir.substring(0,slashPos + 1) + "String_Node_Str";
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(directoryTemplate(context.vertx()).replace("String_Node_Str",normalizedDir).replace("String_Node_Str",parent).replace("String_Node_Str",files.toString()));
      }
 else       if (accept.contains("String_Node_Str")) {
        String file;
        JsonArray json=new JsonArray();
        for (        String s : asyncResult.result()) {
          file=s.substring(s.lastIndexOf('/') + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          json.add(file);
        }
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(json.encode());
      }
 else {
        String file;
        StringBuilder buffer=new StringBuilder();
        for (        String s : asyncResult.result()) {
          file=s.substring(s.lastIndexOf('/') + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          buffer.append(file);
          buffer.append('\n');
        }
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(buffer.toString());
      }
    }
  }
);
}

Fixed version (ground truth):
private void sendDirectory(String dir,RoutingContext context){
  FileSystem fileSystem=context.vertx().fileSystem();
  HttpServerRequest request=context.request();
  fileSystem.readDir(dir,asyncResult -> {
    if (asyncResult.failed()) {
      context.fail(asyncResult.cause());
    }
 else {
      String accept=request.headers().get("String_Node_Str");
      if (accept == null) {
        accept="String_Node_Str";
      }
      if (accept.contains("String_Node_Str")) {
        String normalizedDir=dir.substring(webRoot.length());
        if (!normalizedDir.endsWith("String_Node_Str")) {
          normalizedDir+="String_Node_Str";
        }
        String file;
        StringBuilder files=new StringBuilder("String_Node_Str");
        List<String> list=asyncResult.result();
        Collections.sort(list);
        for (        String s : list) {
          file=s.substring(s.lastIndexOf(File.separatorChar) + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          files.append("String_Node_Str");
          files.append(normalizedDir);
          files.append(file);
          files.append("String_Node_Str");
          files.append(file);
          files.append("String_Node_Str");
          files.append(file);
          files.append("String_Node_Str");
        }
        files.append("String_Node_Str");
        int slashPos=0;
        for (int i=dir.length() - 2; i > 0; i--) {
          if (dir.charAt(i) == '/') {
            slashPos=i;
            break;
          }
        }
        String parent="String_Node_Str" + dir.substring(0,slashPos + 1) + "String_Node_Str";
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(directoryTemplate(context.vertx()).replace("String_Node_Str",normalizedDir).replace("String_Node_Str",parent).replace("String_Node_Str",files.toString()));
      }
 else       if (accept.contains("String_Node_Str")) {
        String file;
        JsonArray json=new JsonArray();
        for (        String s : asyncResult.result()) {
          file=s.substring(s.lastIndexOf(File.separatorChar) + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          json.add(file);
        }
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(json.encode());
      }
 else {
        String file;
        StringBuilder buffer=new StringBuilder();
        for (        String s : asyncResult.result()) {
          file=s.substring(s.lastIndexOf(File.separatorChar) + 1);
          if (!includeHidden && file.charAt(0) == '.') {
            continue;
          }
          buffer.append(file);
          buffer.append('\n');
        }
        request.response().putHeader("String_Node_Str","String_Node_Str");
        request.response().end(buffer.toString());
      }
    }
  }
);
}