Merge branch 'small-fixes' into 'master'

Small fixes

Closes #8542

See merge request !58

src/common/helpers.py

@@ -746,13 +746,13 @@ def play_sound_file(path_to_soundfile):
     path_to_soundfile = check_soundfile_path(path_to_soundfile)
     if path_to_soundfile is None:
         return
-    elif os.name == 'nt' and HAS_WINSOUND:
+    elif sys.platform == 'win32' and HAS_WINSOUND:
         try:
             winsound.PlaySound(path_to_soundfile,
                     winsound.SND_FILENAME|winsound.SND_ASYNC)
         except Exception:
             log.exception('Sound Playback Error')
-    elif os.name == 'posix':
+    elif sys.platform == 'linux':
         if gajim.config.get('soundplayer') == '':
             def _oss_play():
                 sndfile = wave.open(path_to_soundfile, 'rb')

src/config.py

@@ -3254,7 +3254,9 @@ class ManageBookmarksWindow:
         self.xml.connect_signals(self)
         self.window.show_all()
         # select root iter
-        self.selection.select_iter(self.treestore.get_iter_first())
+        first_iter = self.treestore.get_iter_first()
+        if first_iter:
+            self.selection.select_iter(first_iter)
 
     def on_key_press_event(self, widget, event):
         if event.keyval == Gdk.KEY_Escape:

src/roster_window.py

@@ -1558,6 +1558,8 @@ class RosterWindow:
         """
         if not self.tree.get_model():
             return
+        if account not in gajim.connections:
+            return
         delimiter = gajim.connections[account].nested_group_delimiter
         group_splited = group.split(delimiter)
         i = 1