empty agreed, so it should be undef no?

I think this is where you are taking a leap of faith, and leaping in the wrong direction. {grin}

In fact, Perl hints the contrary in perldoc perldata:

       You may have an optional comma before the closing
       parenthesis of a list literal, so that you can say:

           @foo = (
               1,
               2,
               3,
           );
[download]

So there, you're not getting 1,2,3,undef. Just 1,2,3. An extra embedded syntax-only comma was formerly illegal (I believe). I'm a bit surprised to see that it's now being nicely ignored, just as the trailing comma had been, but it's not totally inconsistent with the trailing-comma-ignored feature.

Conclusion: no bug, although not precisely documented to work with embedded comma as well as trailing comma.

-- Randal L. Schwartz, Perl hacker

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