8141148: LDAP "follow" throws ClassCastException with Java 8

Reviewed-by: prappo, xuelei

src/share/classes/com/sun/jndi/ldap/AbstractLdapNamingEnumeration.java

@@ -300,7 +300,7 @@ abstract class AbstractLdapNamingEnumeration<T extends NameClassPair>
         errEx = e;
     }
 
-    protected abstract AbstractLdapNamingEnumeration<T> getReferredResults(
+    protected abstract AbstractLdapNamingEnumeration<? extends NameClassPair> getReferredResults(
             LdapReferralContext refCtx) throws NamingException;
 
     /*
@@ -360,7 +360,7 @@ abstract class AbstractLdapNamingEnumeration<T extends NameClassPair>
      * Merge the entries and/or referrals from the supplied enumeration
      * with those of the current enumeration.
      */
-    protected void update(AbstractLdapNamingEnumeration<T> ne) {
+    protected void update(AbstractLdapNamingEnumeration<? extends NameClassPair> ne) {
         // Cleanup previous context first
         homeCtx.decEnumCount();
 

src/share/classes/com/sun/jndi/ldap/LdapBindingEnumeration.java

@@ -104,9 +104,9 @@ final class LdapBindingEnumeration
     }
 
     @Override
-    protected LdapBindingEnumeration getReferredResults(
+    protected AbstractLdapNamingEnumeration<? extends NameClassPair> getReferredResults(
             LdapReferralContext refCtx) throws NamingException{
         // repeat the original operation at the new context
-        return (LdapBindingEnumeration)refCtx.listBindings(listArg);
+        return (AbstractLdapNamingEnumeration<? extends NameClassPair>)refCtx.listBindings(listArg);
     }
 }

src/share/classes/com/sun/jndi/ldap/LdapNamingEnumeration.java

@@ -72,9 +72,9 @@ final class LdapNamingEnumeration
     }
 
     @Override
-    protected LdapNamingEnumeration getReferredResults(
+    protected AbstractLdapNamingEnumeration<? extends NameClassPair> getReferredResults(
             LdapReferralContext refCtx) throws NamingException {
         // repeat the original operation at the new context
-        return (LdapNamingEnumeration)refCtx.list(listArg);
+        return (AbstractLdapNamingEnumeration<? extends NameClassPair>)refCtx.list(listArg);
     }
 }

src/share/classes/com/sun/jndi/ldap/LdapSearchEnumeration.java

@@ -199,15 +199,15 @@ final class LdapSearchEnumeration
     }
 
     @Override
-    protected LdapSearchEnumeration getReferredResults(
+    protected AbstractLdapNamingEnumeration<? extends NameClassPair> getReferredResults(
             LdapReferralContext refCtx) throws NamingException {
         // repeat the original operation at the new context
-        return (LdapSearchEnumeration)refCtx.search(
+        return (AbstractLdapNamingEnumeration<? extends NameClassPair>)refCtx.search(
                 searchArgs.name, searchArgs.filter, searchArgs.cons);
     }
 
     @Override
-    protected void update(AbstractLdapNamingEnumeration<SearchResult> ne) {
+    protected void update(AbstractLdapNamingEnumeration<? extends NameClassPair> ne) {
         super.update(ne);
 
         // Update search-specific variables