Compiling this program:

class TestDups {
    void test(Object[] o) {
       o.clone();
       o.clone();
    }
}

Leads to duplicate CP entries:

Constant pool:
   #1 = Methodref #5.#14 // java/lang/Object."<init>":()V
   #2 = Methodref #15.#16 // "[Ljava/lang/Object;".clone:()Ljava/lang/Object;
   #3 = Methodref #17.#16 // "[Ljava/lang/Object;".clone:()Ljava/lang/Object; // <--------------------
   #4 = Class #18 // TestDups
   #5 = Class #19 // java/lang/Object
   #6 = Utf8 <init>
   #7 = Utf8 ()V
   #8 = Utf8 Code
   #9 = Utf8 LineNumberTable
  #10 = Utf8 test
  #11 = Utf8 ([Ljava/lang/Object;)V
  #12 = Utf8 SourceFile
  #13 = Utf8 TestDups.java
  #14 = NameAndType #6:#7 // "<init>":()V
  #15 = Class #20 // "[Ljava/lang/Object;"
  #16 = NameAndType #21:#22 // clone:()Ljava/lang/Object; // <--------------------
  #17 = Class #20 // "[Ljava/lang/Object;"
  #18 = Utf8 TestDups
  #19 = Utf8 java/lang/Object
  #20 = Utf8 [Ljava/lang/Object;
  #21 = Utf8 clone
  #22 = Utf8 ()Ljava/lang/Object;