[TYPO3-Solr] Workspaces and Solr / Exception "Unable to retrieve a rootline while calculating the site hash"

[Ingo Pfennigstorf]

Hi,

we are using here a current checkout of the EAP Solr Version and TYPO3 
workspaces (TYPO3 4.5.6). When a user creates or changes something in 
the backend in a not-live-workspace an exception is shown, but the data 
is saved.

This exception ('Unable to retrieve a rootline while calculating the 
site hash') is thrown by solr in class.tx_solr_util.php

Is this a Ext:solr bug?

Thanks and have a nice T3CON11 Week!

Ingo