LoadConfiguration fails to load *.jar

 
# load project resources
    load *.jar

exception while configuring main class loader:
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(String.java:1768)
        at org.codehaus.groovy.tools.LoaderConfiguration.loadFilteredPath(LoaderConfiguration.java:193)
        at org.codehaus.groovy.tools.LoaderConfiguration.configure(LoaderConfiguration.java:113)
        at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:81)
        at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:130)

/**
  * load a possible filtered path. Filters are defined
  * by using the * wildcard like in any shell
  */
private void loadFilteredPath(String filter) {
  if (filter==null) return;
    int starIndex = filter.indexOf(WILDCARD);
    if (starIndex == -1) {
      addFile(new File(filter));
      return;
    }
    boolean recursive = filter.indexOf(ALL_WILDCARD) != -1;
        
    String startDir = starIndex == 0 ? "./" : filter.substring(0, starIndex - 1);
    File root = new File(startDir);

    filter = RegexUtils.quote(filter);
    filter = filter.replaceAll("\\"+WILDCARD+"\\"+WILDCARD, MATCH_ALL);
    filter = filter.replaceAll("\\" + WILDCARD, MATCH_FILE_NAME);
    Pattern pattern = Pattern.compile(filter);

    final File[] files = root.listFiles();
    if (files != null) {
      findMatchingFiles(files, pattern, recursive);
    }
}

String startDir = filter.substring(0, starIndex - 1);

String startDir = starIndex == 0 ? "./" : filter.substring(0, starIndex - 1);