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  1. JDK
  2. JDK-5047224

(reflect) exception thrown from sun.reflect.Reflection.filterFields in Tiger b49

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      Description

      The symptom is a NegativeArraySizeException thrown by a newly introduced
      method, filterFields():

      java.lang.NegativeArraySizeException
              at sun.reflect.Reflection.filterFields(Reflection.java:235)
              at java.lang.Class.privateGetDeclaredFields(Class.java:1884)
              at java.lang.Class.privateGetPublicFields(Class.java:1916)
              at java.lang.Class.getFields(Class.java:1007)
              at
      com.bea.util.jam.internal.reflect.ReflectClassBuilder.populate(ReflectCl
      assBuilder.java:128)

      A comment on this problem:

      >So I looked at the Sun source. filterFields is new in b49 and looks
      like this (the line in question is where newFields gets allocated):
      >
      > public static Field[] filterFields(Class containingClass,
      > Field[] fields) {
      > if (fieldFilterMap == null) {
      > // Bootstrapping
      > return fields;
      > }
      > String[] filteredFieldNames = (String[])
      fieldFilterMap.get(containingClass);
      > if (filteredFieldNames == null) {
      > return fields;
      > }
      > Field[] newFields = new Field[fields.length -
      filteredFieldNames.length];
      > int destIdx = 0;
      > for (int srcIdx = 0; srcIdx < fields.length; srcIdx++) {
      > boolean shouldSkip = false;
      > Field field = fields[srcIdx];
      > for (int tmp = 0; tmp < filteredFieldNames.length; tmp++) {
      > if (field.getName() == filteredFieldNames[tmp]) {
      > shouldSkip = true;
      > break;
      > }
      > }
      > if (!shouldSkip) {
      > newFields[destIdx++] = field;
      > }
      > }
      > return newFields;
      > }
      >
      >Clearly there are more filtered fields than fields which seems a little
      impossible (and a clear bug).
      >

      test case:


      public class Repro {

          public static void main(String[] args) throws ClassNotFoundException {
            Class c=Class.forName("sun.reflect.ConstantPool");
            java.lang.reflect.Field[] f=c.getFields();
            System.out.println("Fields Found: " + f.length);
          }
      }

      Try this against build 49 or 50, and you'll get:

      Exception in thread "main" java.lang.NegativeArraySizeException
              at sun.reflect.Reflection.filterFields(Reflection.java:235)
              at java.lang.Class.privateGetDeclaredFields(Class.java:1884)
              at java.lang.Class.privateGetPublicFields(Class.java:1916)
              at java.lang.Class.getFields(Class.java:1007)
              at Repro.main(Repro.java:5)

          

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              Assignee:
              kbr Kenneth Russell (Inactive)
              Reporter:
              mmma Marvin Ma (Inactive)
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