Comment 1 Dani Megert 2008-05-07 09:37:48 EDT

Any steps to reproduce?

Comment 2 Dani Megert 2008-05-07 09:45:14 EDT

Looked through the call hierarchy and it seems that org.eclipse.jdt.core.CompletionContext.getVisibleElements(String) returns 'null'.

Comment 3 Jerome Lanneluc 2008-05-07 09:52:42 EDT

Looking at the code, I don't see a path were it could possibly return null. David can you please confirm?

Comment 4 Philippe Coucaud 2008-05-07 10:22:31 EDT

I can reproduce the NPE with a debug instance of Eclipse. In ParameterGuesser.parameterProposals(), 'suggestions' is an array of 3 elements. The first element is null. If you tell me where to put breakpoints I can try to provide more information.

Comment 5 David Audel 2008-05-07 10:24:01 EDT

It is not possible to getVisibleElements() return null. An array is always returned but looking at the code i found a path where the array can contain a null value.

Currently i have no real test case to reproduce the bug.

Comment 6 Philippe Coucaud 2008-05-07 10:26:22 EDT

I can reproduce the NPE with a debug instance of Eclipse. In
ParameterGuesser.parameterProposals(), 'suggestions' is an array of 3 elements.
The first element is null. If you tell me where to put breakpoints I can try to
provide more information.

Comment 7 David Audel 2008-05-07 10:28:19 EDT

Can you put a breakpoint in InternalExtendedCompletionContext#getJavaElement() and look if this method is called and return null ?

Comment 8 Philippe Coucaud 2008-05-07 10:36:30 EDT

Yes, it is called and returns null because of the following statement (line 250):

    if (parent == null) return null;

Comment 9 Philippe Coucaud 2008-05-07 10:43:18 EDT

The first branch is taken ('referenceContext instanceof AbstractMethodDeclaration'), meaning that 'parent' remains null after the call to getJavaElementOfCompilationUnit(). 'methodDeclaration.binding' is null.

Comment 10 Jerome Lanneluc 2008-05-07 10:48:53 EDT

Philippe, a test case demonstrating the problem would help even more.

David, I think we should still protect ourselves and shrink the array if it contains nulls.

Comment 11 Philippe Coucaud 2008-05-07 11:02:12 EDT

I can reproduce the NPE with the following class: 

public class Foo  {

	private void addDepencency(int source, int target, int depth) {
	}

	private void addDataDependencies(int source) {
		addD
	}

	private void addDataDependencies(int source) {
	}
}

Just trigger the completion after "addD".

Comment 12 Jerome Lanneluc 2008-05-07 11:27:02 EDT

Thanks Philippe. I was able to reproduce. David please investigate for RC1.

Comment 13 David Audel 2008-05-12 10:59:59 EDT

Created attachment 99725 [details]
Proposed fix

With this patch:
- getVisibleElements() can not return an array with a null value.
- getVisibleElements() return elements which have a parent with no corresponding binding (like duplicate methods)
- AssistSourceField#getKey() and AssistSourceMethod#getKey() andAssistSourceType#getKey() always return a key and never return null.

Comment 14 David Audel 2008-05-12 11:16:09 EDT

Jerome - Could you review my patch ?

Comment 15 Jerome Lanneluc 2008-05-12 11:23:59 EDT

Patch looks good. +1

Comment 16 David Audel 2008-05-12 11:26:43 EDT

Released for 3.4RC1.

Tests added
  CompletionContextTests#test0163() -> test0164()

Comment 17 Jerome Lanneluc 2008-05-14 05:20:07 EDT

Verified for 3.4RC1 using I20080513-2000