Name: saf@russia Date: 08/07/96


This bug was found by St.Petersburg Java SQE team (by Michael Gorshenev).

The java.util.Vector.removeElementAt(int) does not work according the specification.

The Java Language specification
(Pre-Release Version 1.0, Draft 5.2 - July 3, 1996)
says the following (please see item 21.11.16):

"21.11.16 public final void removeElementAt(int index)
throws IndexOutOfBoundsException

The size of this Vector is decreased by 1 and the item at the specified
index is removed from this Vector. Any item in this Vector that was
previously at index k is first moved to index k-1 if and only if k is greater
than index."

The java.util.Vector.removeElementAt(int) with empty vector and parameter -1 does throw ArrayIndexOutOfBoundsException, but it also sets vector size to -1.
 
Here is the minimized test demonstrating the bug:
    

----- java_util_Vector_removeElementAt.java -------------
class java_util_Vector_removeElementAt {
  
  public static void main(String[] argv) {
      java.util.Vector v=new java.util.Vector();
      try {
        v.removeElementAt(-1);
        System.out.println("Test failed: ArrayIndexOutOfBoundsException is not thrown");
      }
      catch (ArrayIndexOutOfBoundsException e) {
       if (v.size()==0)
        System.out.println("Test passed: vector size = 0");
       else
        System.out.println("Test failed: vector size = " + v.size());
      }
   }
}

----- The output of the test: -------------------------

$JAVA java_util_Vector_removeElementAt
Test failed: vector size = -1

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