add warning for failing assignment or fix

[kroeker@…]

The following failing assignment to a list entry produces no warning and no error:

option("warn");
ring rng = 0,x,dp;
list L ;
def dumb = rng,"sdf"; // succeed, list with two entries
dumb;
L[1] = rng,"dumb"; // fails, no warning, no error!!!
L; // is still empty; 

Output:

> option("warn");
> ring rng = 0,x,dp;
> list L ;
> def dumb = rng,"sdf"; // dumb became a list with two entries
> dumb;
[1]:
   //   characteristic : 0
//   number of vars : 1
//        block   1 : ordering dp
//                  : names    x
//        block   2 : ordering C
[2]:
   sdf
> L[1] = rng,"dumb"; // fails, no warning, no error!!!
> L; // is still empty; 
empty list

Proposal: warn or fix

[hannes]

fixed with ef99cd60af79a8e92e84911133464434d82dc603