A DESCRIPTION OF THE PROBLEM :
in method com.sun.org.apache.bcel.internal.util.Class2HTML._main:
when calling argv[i].charAt(0), you should judge argv[i].isEmpty();

such issue is also in https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8279129

ACTUAL -
java.lang.StringIndexOutOfBoundsException: String index out of range: 0
java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:658)
at com.sun.org.apache.bcel.internal.util.Class2HTML._main(Class2HTML.java:148)

---------- BEGIN SOURCE ----------
    @Test
    public void test__main(){
        String[] stringArray0 = {"i53tfnIq_68", "", " #", "^[1]([3-9])[0-9]{9}$"};
        com.sun.org.apache.bcel.internal.util.Class2HTML._main(stringArray0);
    }
---------- END SOURCE ----------

FREQUENCY : occasionally