printers: Fix crash when panel is closed quicklyprinters-fix-crash-when-closing-quicky

Fix a user-after-free while testing the connectivity to a cups
server. This is similar to the fix in commit 1d72a0b.

This is an addition to the changes introduced in commit 2ff5cfd
which allowed the connection testing to be cancellable.

Fixes #51
Fixes https://bugzilla.gnome.org/794632

1 files changed, 6 insertions, 3 deletions

diff --git a/panels/printers/cc-printers-panel.c b/panels/printers/cc-printers-panel.c
index 4815c4520..b9b2ca82b 100644
--- a/panels/printers/cc-printers-panel.c
+++ b/panels/printers/cc-printers-panel.c
@@ -1230,13 +1230,11 @@ connection_test_cb (GObject      *source_object,
                     gpointer      user_data)
 {
   CcPrintersPanelPrivate *priv;
-  CcPrintersPanel        *self = (CcPrintersPanel*) user_data;
+  CcPrintersPanel        *self;
   gboolean                success;
   PpCups                 *cups = PP_CUPS (source_object);
   g_autoptr(GError)       error = NULL;
 
-  priv = self->priv;
-
   success = pp_cups_connection_test_finish (cups, result, &error);
 
   if (error != NULL)
@@ -1244,9 +1242,14 @@ connection_test_cb (GObject      *source_object,
       if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
         {
           g_warning ("Could not test connection: %s", error->message);
+
+          return;
         }
     }
 
+  self = CC_PRINTERS_PANEL (user_data);
+  priv = self->priv;
+
   if (!success)
     {
       priv->cups_status_check_id =