[gnome-music] player: Check GstElement query success

[Marinus Schraal <mschraal src gnome org>]

commit 9c2f0ab517ece5e450c04bfe0877b0a0b439f666
Author: theawless <theawless gmail com>
Date:   Sat Jan 21 17:31:13 2017 +0530

    player: Check GstElement query success
    
    If the gstreamer pipeline duration query (song length) fails then there
    is the possibility that duration returns a negative value and hence
    calls to  GLib.timeout_add with this value crash the application. The
    query also returns a boolean indicating success, use it to make sure we
    get a valid duration or use a set positive value instead.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777541

 gnomemusic/player.py |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gnomemusic/player.py b/gnomemusic/player.py
index 2b9ca44..1a68a38 100644
--- a/gnomemusic/player.py
+++ b/gnomemusic/player.py
@@ -867,8 +867,10 @@ class Player(GObject.GObject):
         padding = self.progressScale.get_style_context().get_padding(
             Gtk.StateFlags.NORMAL)
         width -= padding.left + padding.right
-        duration = self.player.query_duration(Gst.Format.TIME)[1] / 10**9
-        timeout_period = min(1000 * duration // width, 1000)
+        success, duration = self.player.query_duration(Gst.Format.TIME)
+        timeout_period = 1000
+        if success:
+            timeout_period = min(1000 * (duration / 10**9) // width, 1000)
 
         if self.timeout:
             GLib.source_remove(self.timeout)