Porting old fix for issue for StringIndexOutOfBoundsException

[kamilkrzywanski]

@velo check and merge it if you agree :)
Fix #986

[velo]

Any hope we can get a unit test?

[kamilkrzywanski]

@velo
I don’t have a meaningful reproducer—the reproducer is my project, which consists of tens of thousands of classes, and I don’t have time to track down the culprit.
I forget attach issue, it's not my fix - it's proted from querydsl/codegen#40

[velo]

Well, no tests mean this might resurface again

[kamilkrzywanski]

Yes, but when I copy the class where the exception occurs, it doesn’t happen. A broader context is needed—I’m not sure how much.
Still, I think it's worth the risk to merge without tests, as it could attract Eclipse IDE users to QueryDSL. :)
Maybe @NiklasMehner have some reproducer?