Singular
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segfault when calling pOne() when currRing == NULL
https://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=2472
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Author:  jpflori [ Thu Nov 20, 2014 6:50 pm ]
Post subject:  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

Author:  hannes [ Fri Nov 21, 2014 6:54 pm ]
Post subject:  Re: segfault when calling pOne() when currRing == NULL

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.

Author:  jpflori [ Mon Nov 24, 2014 4:26 pm ]
Post subject:  Re: segfault when calling pOne() when currRing == NULL

Thanks, that's exactly what I did!

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