[gtk+] gtkplacessidebar: avoid accessing destroyed popover

[Matthias Clasen <matthiasc src gnome org>]

commit 5c0447fa44ee8bfdad7290025a48e5431a9dfb9d
Author: Carlos Soriano <csoriano gnome org>
Date:   Wed Sep 23 16:13:48 2015 +0200

    gtkplacessidebar: avoid accessing destroyed popover
    
    The row and rename popovers are always relative_to a row.
    We also keep a pointer to them so we can interact with them in
    callbacks.
    
    However, if the row is destroyed its associated popovers will be
    destroyed as well as relative_to destroyes and frees memory of its
    associated widget when its relative_to widget is destroyed.
    If we, for example, update the places while the popover is shown we are
    going to access and invalid widget on the next time.
    
    To avoid that, connect to the destroy signal of the popovers and clean
    the sidebar pointers when that happens.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=755444

 gtk/gtkplacessidebar.c |   30 +++++++++++++++++++++++++++++-
 1 files changed, 29 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkplacessidebar.c b/gtk/gtkplacessidebar.c
index b2e86e3..1ed8abe 100644
--- a/gtk/gtkplacessidebar.c
+++ b/gtk/gtkplacessidebar.c
@@ -2412,7 +2412,21 @@ do_rename (GtkButton        *button,
 
   g_clear_pointer (&sidebar->rename_uri, g_free);
 
-  gtk_widget_hide (sidebar->rename_popover);
+  if (sidebar->rename_popover)
+    gtk_widget_hide (sidebar->rename_popover);
+}
+
+static void
+on_rename_popover_destroy (GtkWidget        *rename_popover,
+                           GtkPlacesSidebar *sidebar)
+{
+  if (sidebar)
+    {
+      sidebar->rename_popover = NULL;
+      sidebar->rename_entry = NULL;
+      sidebar->rename_button = NULL;
+      sidebar->rename_error = NULL;
+    }
 }
 
 static void
@@ -2430,6 +2444,9 @@ create_rename_popover (GtkPlacesSidebar *sidebar)
     return;
 
   popover = gtk_popover_new (GTK_WIDGET (sidebar));
+  /* Clean sidebar pointer when its destroyed, most of the times due to its
+   * relative_to associated row being destroyed */
+  g_signal_connect (popover, "destroy", G_CALLBACK (on_rename_popover_destroy), sidebar);
   gtk_popover_set_position (GTK_POPOVER (popover), GTK_POS_RIGHT);
   grid = gtk_grid_new ();
   gtk_container_add (GTK_CONTAINER (popover), grid);
@@ -3383,6 +3400,14 @@ add_open_button (GtkWidget          *box,
   return item;
 }
 
+static void
+on_row_popover_destroy (GtkWidget        *row_popover,
+                        GtkPlacesSidebar *sidebar)
+{
+  if (sidebar)
+    sidebar->popover = NULL;
+}
+
 /* Constructs the popover for the sidebar row if needed */
 static void
 create_row_popover (GtkPlacesSidebar *sidebar,
@@ -3392,6 +3417,9 @@ create_row_popover (GtkPlacesSidebar *sidebar,
   GtkWidget *box;
 
   sidebar->popover = gtk_popover_new (GTK_WIDGET (sidebar));
+  /* Clean sidebar pointer when its destroyed, most of the times due to its
+   * relative_to associated row being destroyed */
+  g_signal_connect (sidebar->popover, "destroy", G_CALLBACK (on_row_popover_destroy), sidebar);
   setup_popover_shadowing (sidebar->popover);
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   g_object_set (box, "margin", 10, NULL);