[gitg] Avoid updating walker if already disposed or repository is null

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 9f8122b74be4067159ec345e16830e0c99c720dc
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Thu Aug 6 08:49:22 2015 +0200

    Avoid updating walker if already disposed or repository is null
    
    https://bugzilla.gnome.org/show_bug.cgi?id=748974

 gitg/history/gitg-history.vala |   76 +++++++++++++++++++++++++++++-----------
 1 files changed, 55 insertions(+), 21 deletions(-)
---
diff --git a/gitg/history/gitg-history.vala b/gitg/history/gitg-history.vala
index 1ef2fd6..a1141f3 100644
--- a/gitg/history/gitg-history.vala
+++ b/gitg/history/gitg-history.vala
@@ -36,6 +36,9 @@ namespace GitgHistory
                private float d_scroll_y;
                private ulong d_insertsig;
                private Settings d_settings;
+               private uint d_walker_update_idle_id;
+               private ulong d_refs_list_selection_id;
+               private ulong d_refs_list_changed_id;
 
                private Paned d_main;
                private Gitg.PopupMenu d_refs_list_popup;
@@ -69,11 +72,7 @@ namespace GitgHistory
                                if (d_repository != value)
                                {
                                        d_repository = value;
-
-                                       if (value != null)
-                                       {
-                                               reload();
-                                       }
+                                       reload();
                                }
                        }
                }
@@ -134,12 +133,38 @@ namespace GitgHistory
 
                        update_sort_mode();
 
+                       d_repository = application.repository;
+
                        application.bind_property("repository", this,
                                                  "repository", BindingFlags.DEFAULT);
 
                        reload_mainline();
                }
 
+               public override void dispose()
+               {
+                       if (d_refs_list_selection_id != 0)
+                       {
+                               d_main.refs_list.disconnect(d_refs_list_selection_id);
+                               d_refs_list_selection_id = 0;
+                       }
+
+                       if (d_refs_list_changed_id != 0)
+                       {
+                               d_main.refs_list.disconnect(d_refs_list_changed_id);
+                               d_refs_list_changed_id = 0;
+                       }
+
+                       if (d_walker_update_idle_id != 0)
+                       {
+                               Source.remove(d_walker_update_idle_id);
+                               d_walker_update_idle_id = 0;
+                       }
+
+                       d_commit_list_model.repository = null;
+                       base.dispose();
+               }
+
                private void update_sort_mode()
                {
                        if (d_settings.get_boolean("topological-order"))
@@ -375,6 +400,12 @@ namespace GitgHistory
 
                private void reload()
                {
+                       if (d_walker_update_idle_id != 0)
+                       {
+                               Source.remove(d_walker_update_idle_id);
+                               d_walker_update_idle_id = 0;
+                       }
+
                        var view = d_main.commit_list_view;
 
                        double vadj = d_main.refs_list.get_adjustment().get_value();
@@ -474,22 +505,8 @@ namespace GitgHistory
                        d_refs_list_popup = new Gitg.PopupMenu(d_main.refs_list);
                        d_refs_list_popup.populate_menu.connect(on_refs_list_populate_menu);
 
-                       d_main.refs_list.notify["selection"].connect(() => {
-                               update_walker();
-                       });
-
-                       uint idleupdate = 0;
-
-                       d_main.refs_list.changed.connect(() => {
-                               if (idleupdate == 0)
-                               {
-                                       idleupdate = Idle.add(() => {
-                                               idleupdate = 0;
-                                               update_walker();
-                                               return false;
-                                       });
-                               }
-                       });
+                       d_refs_list_selection_id = 
d_main.refs_list.notify["selection"].connect(update_walker_idle);
+                       d_refs_list_changed_id = d_main.refs_list.changed.connect(update_walker_idle);
 
                        d_commit_list_popup = new Gitg.PopupMenu(d_main.commit_list_view);
                        d_commit_list_popup.populate_menu.connect(on_commit_list_populate_menu);
@@ -507,6 +524,23 @@ namespace GitgHistory
                        d_main.commit_list_view.set_search_equal_func(search_filter_func);
                }
 
+               private void update_walker_idle()
+               {
+                       if (d_repository == null)
+                       {
+                               return;
+                       }
+
+                       if (d_walker_update_idle_id == 0)
+                       {
+                               d_walker_update_idle_id = Idle.add(() => {
+                                       d_walker_update_idle_id = 0;
+                                       update_walker();
+                                       return false;
+                               });
+                       }
+               }
+
                private Gtk.Menu? popup_on_ref(Gdk.EventButton? event)
                {
                        int cell_x;