[Bug tree-optimization/57230] [4.7/4.8/4.9 Regression] tree-ssa-strlen incorrectly optimizes a strlen to 0

[mpolacek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57230

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Seems like there's some wrongdoing in handle_char_store; we have
      else if (si != NULL)
        {    
          si = unshare_strinfo (si);
          si->length = build_int_cst (size_type_node, 0);
so that's where the 0 comes from.