[gtk/fix-network-places] placesview: Avoid use-after-free

[Matthias Clasen <matthiasc src gnome org>]

commit 95d48ac2e81df1f382669e4795cc3a9de151a252
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Feb 11 09:14:34 2021 -0500

    placesview: Avoid use-after-free
    
    The places view has questionable code for handling
    'destroy', which seems to trigger use-after-free in
    some cases. Clean this up a bit by acknowledging the
    cancellation fully, rather than relying on the
    destroyed flag.

 gtk/gtkplacesview.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)
---
diff --git a/gtk/gtkplacesview.c b/gtk/gtkplacesview.c
index aec0ddea60..4d26337155 100644
--- a/gtk/gtkplacesview.c
+++ b/gtk/gtkplacesview.c
@@ -986,9 +986,14 @@ network_enumeration_next_files_finished (GObject      *source_object,
 
   if (error)
     {
-      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
-        g_warning ("Failed to fetch network locations: %s", error->message);
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        {
+          g_clear_error (&error);
+          g_object_unref (view);
+          return;
+        }
 
+      g_warning ("Failed to fetch network locations: %s", error->message);
       g_clear_error (&error);
     }
   else
@@ -999,16 +1004,11 @@ network_enumeration_next_files_finished (GObject      *source_object,
       g_list_free_full (detected_networks, g_object_unref);
     }
 
-  g_object_unref (view);
+  update_network_state (view);
+  monitor_network (view);
+  update_loading (view);
 
-  /* avoid to update widgets if we are already destroyed
-     (and got cancelled s a result of that) */
-  if (!view->destroyed)
-    {
-      update_network_state (view);
-      monitor_network (view);
-      update_loading (view);
-    }
+  g_object_unref (view);
 }
 
 static void