Created attachment 101350 [details]
GDB log with "dup fd..." patch

It works!

 Before first close:
$ ls -l /proc/29981/fd/
total 0
lrwx------ 1 user users 64 Jun 19 13:20 0 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 1 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 2 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 3 -> socket:[1333878]
lrwx------ 1 user users 64 Jun 19 13:20 4 -> /dev/dri/card0
lrwx------ 1 user users 64 Jun 19 13:20 5 -> /dev/dri/card0
lrwx------ 1 user users 64 Jun 19 13:20 6 -> /dev/dri/card0

 After first close:
$ ls -l /proc/29981/fd/
total 0
lrwx------ 1 user users 64 Jun 19 13:20 0 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 1 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 2 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 3 -> socket:[1333878]
lrwx------ 1 user users 64 Jun 19 13:20 5 -> /dev/dri/card0
lrwx------ 1 user users 64 Jun 19 13:20 6 -> /dev/dri/card0

 After second close:
$ ls -l /proc/29981/fd/
total 0
lrwx------ 1 user users 64 Jun 19 13:20 0 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 1 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 2 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 3 -> socket:[1333878]
lrwx------ 1 user users 64 Jun 19 13:20 6 -> /dev/dri/card0

 After third close:
$ ls -l /proc/29981/fd/
total 0
lrwx------ 1 user users 64 Jun 19 13:20 0 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 1 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 2 -> /dev/pts/0
lrwx------ 1 user users 64 Jun 19 13:20 3 -> socket:[1333878]