[Bug middle-end/78521] [7 Regression] incorrect byte count in -Wformat-length warning with non-constant width or precision

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78521

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch posted for review:
https://gcc.gnu.org/ml/gcc-patches/2016-11/msg02730.html