Since upgrading to Pipeline:Groovy 2.48, the .empty property of List objects gives very strange results, whose boolean value in particular is the reverse of the expected.
When executing the following script as a pipeline (testet via "Replay" and replacing the existing script by this) gives weird output:
Downgrading the Pipeline:Groovy plugin to 2.47 fixes it; after upgrading again, the weird behaviour is back.
For the moment, I can live with calling isEmpty() instead of accessing empty.
I have not tested whether any other properties besides .empty are affected.