Wrong wildcard substitution with a set of tensors

[tueda]

Imported from https://www.nikhef.nl/~form/forum/viewtopic.php?f=3&t=186.

CF f;
S n;
CT t;
I i;
Set tensors: t;
Set indices: i;
L F = f(1);
id f(n?) = tensors[n](indices[n]);
P "%r";
P;
.end

wrongly gives

FORM 4.1 (Jun 14 2017, v4.1-20131025-356-g541f847) 64-bits  Run: Wed Jun 28 14:29:24 2017

9  151  5  0  -4  130  1  1  3  

   F =
      t(?,i);

The output should be

8  151  4  0  130  1  1  3  

   F =
      t(i);