Linux: initially connected joysticks may not be detected

[alemart]

On Linux, Allegro may not detect initially connected joysticks if al_install_joystick() is called after changing the filesystem interface.

Example

#include <stdio.h>
#include <allegro5/allegro.h>
#include <allegro5/allegro_physfs.h>
#include <physfs.h>

int main(int argc, char **argv)
{
    al_init();
    PHYSFS_init(argv[0]);

    al_set_physfs_file_interface(); // comment this line
    al_install_joystick();

    int num_joysticks = al_get_num_joysticks();
    printf("num_joysticks: %d\n", num_joysticks);

    PHYSFS_deinit();
    return 0;
}

Actual output (start the app with a connected joystick)

num_joysticks: 0

Expected output

num_joysticks: 1