Bug 67890 [PropertiesView] Exception when entries added to properties view
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetEntry.java
}
    /* (non-Javadoc)
     * Method declared on IPropertySheetEntry.
     */
    public boolean hasChildEntries() {
        if (childEntries != null && childEntries.length > 0)
            return true;
        
        return computeMergedPropertyDescriptors().size() > 0;
    }
    /**
     * Update our child entries.
     * This implementation tries to reuse child entries if possible 
     * (if the id of the new descriptor matches the descriptor id of the
     * old entry).
     */
    private void refreshChildEntries() {
        if (childEntries == null)
            
            return;
        
        List descriptors = computeMergedPropertyDescriptors();
        
        Map entryCache = new HashMap(childEntries.length * 2 + 1);
        for (int i = 0; i < childEntries.length; i++) {
            entryCache.put(childEntries[i].getDescriptor().getId(),
                    childEntries[i]);
        }
        
        List entriesToDispose = new ArrayList(Arrays.asList(childEntries));