Allow for specifying SearchIndex indexingConfigurationClass without explicit indexingConfiguration

Currently, the indexingConfiguration parameter seems to be optional in Jackrabbit repository and workspace configuration files. So I would expect it to remain optional, even if I override the indexingConfigurationClass parameter. If found some relevant documentation here:
http://wiki.apache.org/jackrabbit/Search

This documentation, however, doesn't disclose the fact that an indexingConfiguration is always needed for indexingConfigurationClass to be considered, which can be seen in SearchIndex:

protected IndexingConfiguration createIndexingConfiguration(NamespaceMappings namespaceMappings) {
Element docElement = getIndexingConfigurationDOM();
if (docElement == null)

{ return null; }

Here are a couple of suggestions:

1. Short-term fix: Document this behaviour and create a warning message, when indexingConfigurationClass is specified, but indexingConfiguration is not. This problem should not be "swallowed"
2. Long-term fix: Allow for these two parameters to be configured independently of one another (if that makes sense)