[Bug middle-end/77671] missing -Wformat-overflow warning on sprintf overflow with "%s"

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77671

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch posted for review:
https://gcc.gnu.org/ml/gcc-patches/2017-04/msg00968.html