HR bugfix - #186321 [69cat] IndexOutOfBoundsException: Index: 0, Size: 0

http://netbeans.org/bugzilla/show_bug.cgi?id=186321

Description: The SourceForBinaryQuery causes IndexOutOfBoundsException  
when a project depends on the freeform project output and the freeform  
project has no annotation
processing enabled.

Impact: The freeform project without annotation processor support  
cannot be used as a library project.

Risk assessment: Simple fix only checking if the cache is empty.

http://hg.netbeans.org/jet-main/rev/b4f712722bb0

Review by Jan Lahoda.

Thanks for review,
Tomas