bug in primdecGTZ() with minpoly, char=5

[jakobkroeker]

upstream: http://www.singular.uni-kl.de:8002/trac/ticket/707#ticket

LIB("primdec.lib");
system("random",1580702082);
ring rng = (5,vv),(x,y,z),dp;
minpoly = (vv^2-2);
ideal I = (-2*vv)*x*z+(-vv)*y^3,x*y*z-2*x*y+2*y^3,-x+z^2+(-2*vv);
list  PL,ML;
list L1 =  primdecGTZ (I);
list L2 = primdecSY (I);
L1;
L2;

testPrimary(L1 , I) ;  // fails
testPrimary(L2 , I) ; 

idealsEqual(L1[1][2],L2[3][2]); //ok
idealsEqual(L1[1][1],L2[3][1]); //ok
idealsEqual(L1[3][2],L2[1][2]); //ok
idealsEqual(L1[3][1],L2[1][1]); //ok
idealsEqual(L1[2][2],L2[2][2]); //ok
idealsEqual(L1[2][1],L2[2][1]); //ok

// here is the issue:
idealsEqual(L1[4][2],L2[4][2]); //ok
idealsEqual(L1[4][1],L2[4][1]); //=0

output

> L1[4][1]; //wrong
_[1]=y
_[2]=x
_[3]=z^2-x+(-2*vv)

> L2[4][1];
_[1]=x
_[2]=z^2+(-2*vv)
_[3]=y^3

[jakobkroeker]

fixed (see http://www.singular.uni-kl.de:8002/trac/ticket/707#ticket)