[Bug fortran/91310] Read overflow generated by character array assignment to self

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91310

--- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Comment on attachment 46648
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46648
test case 1

Oops, correction. If len is small enough, the test case can be
valid (well, it could be if str was ever assigned).

Digging further...