Hi,
thanks for reporting the bug. I am about to fix it.
Excellent ! Please ping me either on this list or directly when you have the fix, so that we (ie: the Sage dev team) can decide either to backport it or to upgrade GiNaC.
Ping.
Wow ! That's a blazingly fast fix !
Generally, it is best to open a ticket in Sage trac, so you can be sure the problem is going to be fixed. This is because as far as I know patches for GiNaC don't automatically propagate to Pynac.
Of course ! See <http://trac.sagemath.org/sage_trac/ticket/11352> Ticket #11352 (is_polynomial returns wrong results) Opened 31 hours ago
Anyway, in this case you'll have to port these two patches to Pynac: <http://www.ginac.de/ginac.git?p=ginac.git;a=commitdiff;h=0c2f0f4c6d> <http://www.ginac.de/ginac.git?p=ginac.git;a=commitdiff;h=293ff6f6fe>
I'm copy this info to sage trac ticket and waiting for symbolic guys to decide what to do further with PyNaC. Thanks a lot. Cheers, Florent