accessing #factdollar factors causes program termination

[spj101]

On commit 3767258d853a6f698f66bd4fd2d5c8f6fbf710d2 if I try to factorise an expression containing only an integer, the number of factors reported is 1 but accessing factor 1 causes the program to terminate.

Input:

#-
Symbol x;
#$a = 1;  * Error
*#$a = x;  * Fine
#factdollar $a;
#write "Number of factors in `$a' is `$a[0]'"
#write "Factor 1 is `$a[1]'"
.end

Output:

FORM 4.2.0 (Jul 13 2017, v4.2.0-10-g3767258) 64-bits  Run: Fri Jul 14 16:00:02 2017
    #-
Number of factors in 1 is 1
Program terminating at test.frm Line 3 -->
  0.00 sec out of 0.00 sec

[spj101]

Thanks on commit 2bbb45f892199bfbc0d2bd6a2b5bba57c3739838 this is working for me!