[MM] [PATCH] iface-modem: fix a crash due to removed signal_quality_check context

[Ben Chan <benchan chromium org>]

---
 src/mm-iface-modem.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/mm-iface-modem.c b/src/mm-iface-modem.c
index e3165f2..d49787f 100644
--- a/src/mm-iface-modem.c
+++ b/src/mm-iface-modem.c
@@ -843,9 +843,12 @@ signal_quality_check_ready (MMIfaceModem *self,
     } else
         update_signal_quality (self, signal_quality, TRUE);
 
-    /* Remove the running tag */
+    /* Remove the running tag. Note that the context may have been removed by
+     * mm_iface_modem_shutdown when this function is invoked as a callback of
+     * load_signal_quality. */
     ctx = g_object_get_qdata (G_OBJECT (self), signal_quality_check_context_quark);
-    ctx->running = FALSE;
+    if (ctx)
+        ctx->running = FALSE;
 }
 
 static gboolean
-- 
1.7.7.3