[gnome-online-accounts] webview: Be careful about NULL when handling weak pointers

[Debarshi Ray <debarshir src gnome org>]

commit 184b4d75b83e855f4ba62923ee8e7ca9fd0e5fd2
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu May 7 19:53:10 2015 +0200

    webview: Be careful about NULL when handling weak pointers
    
    If the weak pointer got nullified due to the object being finalized,
    then there is no pointer left to be removed. Trying to do so will lead
    to a CRITICAL.
    
    Similarly, we can't add a weak reference to NULL.

 src/goabackend/goawebview.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/goabackend/goawebview.c b/src/goabackend/goawebview.c
index 32999f9..9e48776 100644
--- a/src/goabackend/goawebview.c
+++ b/src/goabackend/goawebview.c
@@ -391,7 +391,9 @@ goa_web_view_finalize (GObject *object)
   GoaWebViewPrivate *priv = self->priv;
 
   g_free (priv->existing_identity);
-  g_object_remove_weak_pointer (G_OBJECT (priv->provider), (gpointer *) &priv->provider);
+
+  if (priv->provider != NULL)
+    g_object_remove_weak_pointer (G_OBJECT (priv->provider), (gpointer *) &priv->provider);
 
   G_OBJECT_CLASS (goa_web_view_parent_class)->finalize (object);
 }
@@ -410,7 +412,8 @@ goa_web_view_set_property (GObject *object, guint prop_id, const GValue *value,
 
     case PROP_PROVIDER:
       priv->provider = GOA_PROVIDER (g_value_get_object (value));
-      g_object_add_weak_pointer (G_OBJECT (priv->provider), (gpointer *) &priv->provider);
+      if (priv->provider != NULL)
+        g_object_add_weak_pointer (G_OBJECT (priv->provider), (gpointer *) &priv->provider);
       break;
 
     default: