Bug 117493 [content assist] CompletionRequestor#completionFailure(IProblem)) is ignored
This got introduced after 3.2 M1 (i.e. broken in 3.2 M2 and newer). If completion fails we now always show: "No completion available." instead of the real error text. Example: for (Iterator i=things.iterator(); i.<ctrl-space> // Iterator not yet imported)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProcessor.java
* @param restrict <code>true</code> if proposals should be restricted
	 */
	public void restrictProposalsToMatchingCases(boolean restrict) {
		
	}
	/*
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
	 */
	public String getErrorMessage() {
		if (fNumberOfComputedResults == 0)
			return JavaUIMessages.JavaEditor_codeassist_noCompletions;
		return null;
	}
	/*
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
	 */
	public IContextInformationValidator getContextInformationValidator() {
		if (fValidator == null)
			fValidator= new JavaParameterListValidator();
		return fValidator;
	}
	/*
	 * @see org.eclipse.jdt.internal.ui.text.java.ContentAssistProcessor#filterAndSort(java.util.List, org.eclipse.core.runtime.IProgressMonitor)
	 */
	protected List filterAndSortProposals(List proposals, IProgressMonitor monitor, TextContentAssistInvocationContext context) {
		filter(proposals, context);
		Collections.sort(proposals, fComparator);
		fNumberOfComputedResults= proposals.size();
		return proposals;
	}