Check for xdg-open or player command before running it. #1003
Description
If xdg-open is not installed, a fresh gpodder instance will fail to play episodes and not provide a reason why, unless the command line is visible or logs are viewed. It should check for the existence of xdg-open, or any command the user has supplied, and display a dialog if not found.
File "/home/test/gpodder/src/gpodder/util.py", line 1433, in gui_open
Popen(['xdg-open', filename], close_fds=True)
File "/home/test/gpodder/src/gpodder/util.py", line 2019, in __init__
super(Popen, self).__init__(*args, **kwargs) # Python 2 syntax
File "/usr/lib/python3.8/subprocess.py", line 858, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/usr/lib/python3.8/subprocess.py", line 1706, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: 'xdg-open'