redSB leads to infinite loop in std

[Oleksandr]

> ring r = 0, (y), (a(-1), dp); y+1;
1+y
> std(ideal(1+y));
_[1]=1+y
> option(redSB); // due to this "reduced SB" option
> std(ideal(1+y)); // std never stops!!!

the Singularg outputs (in an endless loop):

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dc6baf0 size:40 allocated at  ../kernel/pInline1.h:100

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd2230 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd2230 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dc6baf0 size:40 allocated at  ../kernel/pInline1.h:100

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd2380 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd2380 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dc6baf0 size:40 allocated at  ../kernel/pInline1.h:100

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd24d0 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dcd24d0 size:40 allocated at  ../kernel/p_Copy__T.cc:25

// ***dPolyError: monoms p and p->next are equal 
 occured at
 occured for poly:  addr:0x7f552dc6baf0 size:40 allocated at  ../kernel/pInline1.h:100

and so on...

[Oleksandr]

btw,

ring r = 0, (y), (ls); 

or

ring r = 0, (y), (ds); 

do NOT expose this behavior.

the weighting vector with negative entries seems to be guilty...

[hannes]

missing cancelunit added