Allow cancellation of avatar load operations

Automatically cancel all pending avatar load operations when disposing of
an EmpathyIndividualStore. This prevents crashes when linking individuals in
the case that the EmpathyIndividualStore in the linking dialogue gets
notified of the new linked individual just before it's destroyed.

3 files changed, 54 insertions, 13 deletions

diff --git a/libempathy-gtk/empathy-individual-store.c b/libempathy-gtk/empathy-individual-store.c
index 161787299..26b56954e 100644
--- a/libempathy-gtk/empathy-individual-store.c
+++ b/libempathy-gtk/empathy-individual-store.c
@@ -71,6 +71,8 @@ typedef struct
   guint setup_idle_id;
   gboolean dispose_has_run;
   GHashTable *status_icons;
+  /* List of owned GCancellables for each pending avatar load operation */
+  GList *avatar_cancellables;
 } EmpathyIndividualStorePriv;
 
 typedef struct
@@ -552,13 +554,16 @@ individual_store_contact_active_cb (ShowActiveData *data)
   return FALSE;
 }
 
+typedef struct {
+  EmpathyIndividualStore *store; /* weak */
+  GCancellable *cancellable; /* owned */
+} LoadAvatarData;
+
 static void
-individual_avatar_pixbuf_received_cb (GObject *object,
+individual_avatar_pixbuf_received_cb (FolksIndividual *individual,
     GAsyncResult *result,
-    gpointer user_data)
+    LoadAvatarData *data)
 {
-  FolksIndividual *individual = FOLKS_INDIVIDUAL (object);
-  EmpathyIndividualStore *self = user_data;
   GError *error = NULL;
   GdkPixbuf *pixbuf;
 
@@ -572,18 +577,32 @@ individual_avatar_pixbuf_received_cb (GObject *object,
           error->message);
       g_clear_error (&error);
     }
-  else
+  else if (data->store != NULL)
     {
       GList *iters, *l;
 
-      iters = individual_store_find_contact (self, individual);
+      iters = individual_store_find_contact (data->store, individual);
       for (l = iters; l; l = l->next)
         {
-          gtk_tree_store_set (GTK_TREE_STORE (self), l->data,
+          gtk_tree_store_set (GTK_TREE_STORE (data->store), l->data,
               EMPATHY_INDIVIDUAL_STORE_COL_PIXBUF_AVATAR, pixbuf,
               -1);
         }
     }
+
+  /* Free things */
+  if (data->store != NULL)
+    {
+      EmpathyIndividualStorePriv *priv = GET_PRIV (data->store);
+
+      g_object_remove_weak_pointer (G_OBJECT (data->store),
+          (gpointer *) &data->store);
+      priv->avatar_cancellables = g_list_remove (priv->avatar_cancellables,
+          data->cancellable);
+    }
+
+  g_object_unref (data->cancellable);
+  g_slice_free (LoadAvatarData, data);
 }
 
 static void
@@ -604,6 +623,7 @@ individual_store_contact_update (EmpathyIndividualStore *self,
   gboolean do_set_refresh = FALSE;
   gboolean show_avatar = FALSE;
   GdkPixbuf *pixbuf_status;
+  LoadAvatarData *load_avatar_data;
 
   priv = GET_PRIV (self);
 
@@ -678,8 +698,19 @@ individual_store_contact_update (EmpathyIndividualStore *self,
       show_avatar = TRUE;
     }
 
-  empathy_pixbuf_avatar_from_individual_scaled_async (individual,
-      individual_avatar_pixbuf_received_cb, 32, 32, self);
+  /* Load the avatar asynchronously */
+  load_avatar_data = g_slice_new (LoadAvatarData);
+  load_avatar_data->store = self;
+  g_object_add_weak_pointer (G_OBJECT (self),
+      (gpointer *) &load_avatar_data->store);
+  load_avatar_data->cancellable = g_cancellable_new ();
+
+  priv->avatar_cancellables = g_list_prepend (priv->avatar_cancellables,
+      load_avatar_data->cancellable);
+  empathy_pixbuf_avatar_from_individual_scaled_async (individual, 32, 32,
+      load_avatar_data->cancellable,
+      (GAsyncReadyCallback) individual_avatar_pixbuf_received_cb,
+      load_avatar_data);
 
   pixbuf_status =
       empathy_individual_store_get_individual_status_icon (self, individual);
@@ -957,6 +988,14 @@ individual_store_dispose (GObject *object)
     return;
   priv->dispose_has_run = TRUE;
 
+  /* Cancel any pending avatar load operations */
+  for (l = priv->avatar_cancellables; l != NULL; l = l->next)
+    {
+      /* The cancellables are freed in individual_avatar_pixbuf_received_cb() */
+      g_cancellable_cancel (G_CANCELLABLE (l->data));
+    }
+  g_list_free (priv->avatar_cancellables);
+
   contacts = empathy_individual_manager_get_members (priv->manager);
   for (l = contacts; l; l = l->next)
     {
diff --git a/libempathy-gtk/empathy-ui-utils.c b/libempathy-gtk/empathy-ui-utils.c
index 46a26d8f7..0a2d4f4f4 100644
--- a/libempathy-gtk/empathy-ui-utils.c
+++ b/libempathy-gtk/empathy-ui-utils.c
@@ -564,7 +564,7 @@ avatar_file_load_contents_cb (GObject      *object,
 {
 	GFile *file = G_FILE (object);
 	PixbufAvatarFromIndividualClosure *closure = user_data;
-	char *data;
+	char *data = NULL;
 	gsize data_size;
 	struct SizeData size_data;
 	GError *error = NULL;
@@ -617,9 +617,10 @@ out:
 void
 empathy_pixbuf_avatar_from_individual_scaled_async (
 		FolksIndividual     *individual,
-		GAsyncReadyCallback  callback,
 		gint                 width,
 		gint                 height,
+		GCancellable        *cancellable,
+		GAsyncReadyCallback  callback,
 		gpointer             user_data)
 {
 	GFile *avatar_file;
@@ -639,7 +640,7 @@ empathy_pixbuf_avatar_from_individual_scaled_async (
 	if (closure == NULL)
 		goto out;
 
-	g_file_load_contents_async (avatar_file, NULL,
+	g_file_load_contents_async (avatar_file, cancellable,
 			avatar_file_load_contents_cb, closure);
 
 	g_object_unref (result);
diff --git a/libempathy-gtk/empathy-ui-utils.h b/libempathy-gtk/empathy-ui-utils.h
index 9c3ec6517..0b76d09a3 100644
--- a/libempathy-gtk/empathy-ui-utils.h
+++ b/libempathy-gtk/empathy-ui-utils.h
@@ -77,9 +77,10 @@ GdkPixbuf *   empathy_pixbuf_from_data_and_mime         (gchar            *data,
 							 gsize             data_size,
 							 gchar           **mime_type);
 void empathy_pixbuf_avatar_from_individual_scaled_async (FolksIndividual     *individual,
-							 GAsyncReadyCallback  callback,
 							 gint                 width,
 							 gint                 height,
+							 GCancellable        *cancellable,
+							 GAsyncReadyCallback  callback,
 							 gpointer             user_data);
 GdkPixbuf * empathy_pixbuf_avatar_from_individual_scaled_finish (
 							 FolksIndividual  *individual,