segfault when calling pOne() when currRing == NULL

Hi all,

Still playing with Singular 3-1-7p1 in debug mode and Sage, we got a segfault when pOne gets called but currRing is not set.
With Singular 3-1-6 it was not the case.
See trac.sagemath.org/ticket/17184#comment:48 and following comments.

I think the following commit might explain the behavior change:
* bceefc05ad02b92a823faffb7a4a247a0da12fc0

Just removing the "#if 0" fixes our problem.
Though it surely is better to fix the issue and leave it there, or revert the whole commit.

Or should always make completely sure there is a currRing set?

Best,
JP

All of the polynomial routines require a ring, as argument or via the global variable currRing. If such a ring does not exit, an error should be reported.
The problem here is the place to check this: 3-1-6 does it during the resolution
of reserved names (IsCmd) while 4-0-0 should check during the evaluation of expressions.
The easiest way to fix it is really to change the "#if 0" to "#if 1" as the check during the evaluation is missing and also not necessary for 3-1-7.

Thanks, that's exactly what I did!