Breaking Changeset: 4802647: Throw required NPEs from removeAll()/retainAll()

[Alan Bateman]

On 04/06/2013 10:14, Ali Ebrahimi wrote:
> :
>
>
> the cause of this error is this new changeset:
>
> 4802647: Throw required NPEs from removeAll()/retainAll()
>
> current code assume that collection.removeAll(null) doesn't do anything.
> but with this changeset produces NullPointerException that doesn't handled.
>
> following is part of source code org/antlr/tool/CompositeGrammar.java
> (see********
> )
>
>    217   	/** Get delegates below direct delegates of g */
>    218   	public List<Grammar>  getIndirectDelegates(Grammar g) {
>    219   		List<Grammar>  direct = getDirectDelegates(g);
>    220   		List<Grammar>  delegates = getDelegates(g);  221
> 		delegates.removeAll(direct);********
>    222   		return delegates;
>    223   	}
>    224
>    225   	/** Return list of delegate grammars from root down to g.
>    226   	 *  Order is root, ..., g.parent.  (g not included).
>    227   	 */
>    228   	public List<Grammar>  getDelegators(Grammar g) {
>    229   		if ( g==delegateGrammarTreeRoot.grammar ) {
>    230   			return null;**********  231   		}
>    232   		List<Grammar>  grammars = new ArrayList();
>    233   		CompositeGrammarTree t = delegateGrammarTreeRoot.findNode(g);
>    234   		// walk backwards to root, collecting grammars
>    235   		CompositeGrammarTree p = t.parent;
>    236   		while ( p!=null ) {
>    237   			grammars.add(0, p.grammar); // add to head so in order later
>    238   			p = p.parent;
>    239   		}
>    240   		return grammars;  241   	}
>
>
> So this changeset at least breaks 'antlr' third-party library and any apps
> depends on.
Thanks for the bug report. It does seem to have exposed a bug in antlr. 
Kevin Rushforth (FX) and Mike Duigou have been looking into the same 
thing via 8015656.

-Alan.