[gnome-music/wip/smcv/issue410] scrobbler: Don't crash if gnome-online-accounts is unavailable

[Simon McVittie <smcv src gnome org>]

commit da026cc26c217540bfa7eb6224d1534869c09aab
Author: Simon McVittie <smcv debian org>
Date:   Sun Aug 30 15:17:33 2020 +0100

    scrobbler: Don't crash if gnome-online-accounts is unavailable
    
    goa_client_get_manager() can return NULL (in Python,
    GoaClient.get_manager() can return None) if the gnome-online-accounts
    D-Bus service is not available. last.fm support is not a critical
    feature, so the GOA service should not be a hard dependency.
    
    Resolves: https://gitlab.gnome.org/GNOME/gnome-music/-/issues/410
    Bug-Debian: https://bugs.debian.org/969271
    Signed-off-by: Simon McVittie <smcv debian org>

 gnomemusic/scrobbler.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
---
diff --git a/gnomemusic/scrobbler.py b/gnomemusic/scrobbler.py
index 04888594..71f13085 100644
--- a/gnomemusic/scrobbler.py
+++ b/gnomemusic/scrobbler.py
@@ -76,11 +76,15 @@ class GoaLastFM(GObject.GObject):
             return
 
         manager = self._client.get_manager()
-        try:
-            manager.call_is_supported_provider(
-                "lastfm", None, self._lastfm_is_supported_cb)
-        except TypeError:
-            self._log.warning("Error: Unable to check if last.fm is supported")
+
+        if manager is not None:
+            try:
+                manager.call_is_supported_provider(
+                    "lastfm", None, self._lastfm_is_supported_cb)
+            except TypeError:
+                self._log.warning("Error: Unable to check if last.fm is supported")
+        else:
+            self._log.info("GNOME Online Accounts not available")
 
     def _lastfm_is_supported_cb(self, proxy, result):
         try: