Unexpected Result from gsl_sf_hyperg_1F1_int with zero inputs

[Jackson Vanover]

Using version 2.6 of GSL from ftp://ftp.gnu.org/gnu/gsl/gsl-2.6.tar.gz

OS is Ubuntu 18.04.2 LTS

Hardware is a Dell workstation with a 3.60 GHz Intel i7-4790 and 32 GB
of RAM

Compiler is gcc 7.4.0 with the -w option

Description: when the first two arguments passed to gsl_sf_hyperg_1F1_int
are zero, the return is 1.105170918075647712442e+00. This is unexpected
because, based on the series definition of the function, this should result
in an indeterminate 0/0 calculation. Given the same inputs, SciPy and
mpmath both appear to recognize this and return a special-value or throw
exceptions.

#include <gsl/gsl_sf.h>
#include <stdio.h>
#include <gsl/gsl_math.h>

int main (void){
        double out;
        out = gsl_sf_hyperg_1F1_int(0,0, 0.1);

        printf("%.21e\n", out);
        return 0;
}

Best,
Jackson Vanover