Bug using polynomial ring as coefficient ring

[anonymous]

Here is a minimal example: running the following code twice

ring F = 0,(a,b),dp;
ring R = F,(c),dp;
ideal I = c;
std(I);

then use

ring F = 0,(a),dp;

leads to a segment fault. If the first part is only run once then the error will not happen.

                     SINGULAR                                 /  Development
 A Computer Algebra System for Polynomial Computations       /   version 4.2.0
                                                           0<
 by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann     \   Dec 2020
FB Mathematik der Universitaet, D-67653 Kaiserslautern        \
> ring F = 0,(a,b),dp;
> ring R = F,(c),dp;
> ideal I = c;
> std(I);
_[1]=c
> ring F = 0,(a,b),dp;
// ** redefining F (ring F = 0,(a,b),dp;)
> ring R = F,(c),dp;
// ** redefining R (ring R = F,(c),dp;)
> ideal I = c;
> std(I);
_[1]=c
> ring F = 0,(a),dp;
// ** redefining F (ring F = 0,(a),dp;)
Singular : signal 11 (v: 4202):
current line:>>ring F = 0,(a),dp;<<
Segment fault/Bus error occurred at 7fe2ee6fd030 because of 10202 (r:1619176513)
please inform the authors
trying to restart...

[hannes]

fixed with 1f547ed4cc617ebefd435098637414a0fabd2084