If I start up with `mged -c`, attach to ogl, close the graphics window then try to `attach ogl` again mged exits with code 01.
This is the output:
X Error of failed request: BadDrawable (invalid Pixmap or Window parameter)
Major opcode of failed request: 128 (XFree86-DRI)
Minor opcode of failed request: 7 ()
Resource id in failed request: 0x2200004
Serial number of failed request: 5602
Current serial number in output stream: 5602
Program exited with code 01.
Doing the same procedure with X replacing ogl works without problems.