[Bug c/79691] -Wformat-truncation suppressed by (and only by) -Og

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79691

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch posted for review:
https://gcc.gnu.org/ml/gcc-patches/2017-02/msg01480.html