https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61847
--- Comment #2 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
Please see PR36857 for some background.
gfortran uses the glibc strtod functions to convert the string to real. I think
in your C code you need to do something like this:
setlocale(LC_ALL, "C");
badcall_();
setlocale(LC_ALL, "de_DE.UTF-8");
and then if your locale does use comma for the decimal point, do this on the
FORTRAN side.
open(unit=1,file='bug.dat', decimal="comma")
