gfortran allows variable to be declared twice

[Vivek Rao via fortran]

The code

function foo(fp, m) result(ft)real   , intent(in) :: fp(m)
integer, intent(in) :: m
integer             :: m
ft = 0.0

end function foo

declares "m" twice, but GNU Fortran (GCC) 7.0.1 20170122 (experimental) on Windows 10 compiles it.
If fp(m) is replace by fp, gfortran catches the error.

Thanks to the gfortran developers for their efforts.