Fix None find paths (#541).

borgmatic/borg/list.py

@@ -92,6 +92,8 @@ def make_find_paths(find_paths):
 
       ['sh:**/*foo.txt*/**', 'pp:root/somedir']
     '''
+    if not find_paths:
+        return ()
 
     return tuple(
         find_path

tests/unit/borg/test_list.py

@@ -258,8 +258,8 @@ def test_make_list_command_includes_additional_flags(argument_name):
     assert command == ('borg', 'list', '--' + argument_name.replace('_', '-'), 'value', 'repo')
 
 
-def test_make_find_paths_passes_through_empty_paths():
-    assert module.make_find_paths(()) == ()
+def test_make_find_paths_considers_none_as_empty_paths():
+    assert module.make_find_paths(None) == ()
 
 
 def test_make_find_paths_passes_through_patterns():