Bug 89505 [code manipulation] generate ctor using fields: duplicate warning does not consider erasure
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/actions/GenerateConstructorUsingFieldsValidator.java
for (int index= 0; index < types.length; index++)
			buffer.append(types[index].getName());
		if (selection != null) {
			for (int index= 0; index < selection.length; index++)
				if (selection[index] instanceof IVariableBinding)
					buffer.append(((IVariableBinding) selection[index]).getType().getName());
		}
	}
	private List getExistingConstructorSignatures() {
		List existing= new ArrayList();
		IMethodBinding[] methods= fType.getDeclaredMethods();
		for (int index= 0; index < methods.length; index++) {
			if (methods[index].isConstructor()) {
				StringBuffer buffer= new StringBuffer();
				createSignature(methods[index], buffer, null);
				existing.add(buffer.toString());
			}
		}
		return existing;
	}
	public IStatus validate(Object[] selection) {
		StringBuffer buffer= new StringBuffer();
		final IMethodBinding constructor= fDialog.getSuperConstructorChoice();
		createSignature(constructor, buffer, selection);
		if (fSignatures.contains(buffer.toString()))
			return new StatusInfo(IStatus.WARNING, ActionMessages.GenerateConstructorUsingFieldsAction_error_duplicate_constructor); 
		return new StatusInfo(IStatus.INFO, Messages.format(ActionMessages.GenerateConstructorUsingFieldsAction_fields_selected, new Object[] { String.valueOf(countSelectedFields(selection)), String.valueOf(fEntries)})); 
	}
}