[epiphany] embed-shell: avoid problems when toggling adblock settings

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a66cc9c7435f8282759b8bb5faeb5cb715c63b23
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Jan 22 22:55:57 2017 -0600

    embed-shell: avoid problems when toggling adblock settings

 embed/ephy-embed-shell.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/embed/ephy-embed-shell.c b/embed/ephy-embed-shell.c
index b3c7d29..8e2cfcc 100644
--- a/embed/ephy-embed-shell.c
+++ b/embed/ephy-embed-shell.c
@@ -762,7 +762,8 @@ ephy_embed_shell_retrieve_filter_file_finished (GFile                     *src,
 
     /* If failed to retrieve, create an empty file if it doesn't exist to unblock extensions */
     stream = g_file_create (data->filter_file, G_FILE_CREATE_NONE, NULL, NULL);
-    g_object_unref (stream);
+    if (stream)
+      g_object_unref (stream);
 
     if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
       g_warning ("Error retrieving filter %s: %s\n", g_file_get_uri (data->src_file), error->message);
@@ -859,9 +860,14 @@ ephy_embed_shell_remove_old_adblock_filters (EphyEmbedShell *shell,
 static void
 ephy_embed_shell_update_adblock_filter_files (EphyEmbedShell *shell)
 {
+  EphyEmbedShellPrivate *priv = ephy_embed_shell_get_instance_private (shell);
   char **filters;
   GList *files = NULL;
 
+  /* One at a time please! */
+  if (priv->uri_tester_update_cancellable)
+    g_cancellable_cancel (priv->uri_tester_update_cancellable);
+
   if (!g_settings_get_boolean (EPHY_SETTINGS_WEB, EPHY_PREFS_WEB_ENABLE_ADBLOCK)) {
     ephy_embed_shell_remove_old_adblock_filters (shell, files);
     return;