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:

 Script

x = [] as List
println x
println x.isEmpty()
println x.empty
x<<"hello"
println x
println x.isEmpty()
println x.empty

Expected output

[Pipeline] echo
[]
[Pipeline] echo
true
[Pipeline] echo
true
[Pipeline] echo
[hello]
[Pipeline] echo
false
[Pipeline] echo
false
[Pipeline] End of Pipeline

Actual output

[Pipeline] echo
[]
[Pipeline] echo
true
[Pipeline] echo
[]
[Pipeline] echo
[hello]
[Pipeline] echo
false
[Pipeline] echo
[false]
[Pipeline] End of Pipeline

Downgrading the Pipeline:Groovy plugin to 2.47 fixes it; after upgrading again, the weird behaviour is back.

Workaround

For the moment, I can live with calling isEmpty() instead of accessing empty.

further considerations

I have not tested whether any other properties besides .empty are affected.