[gnome-documents] toolbar: add back button if required when populating

[Cosimo Cecchi <cosimoc src gnome org>]

commit f47d4fe8c02629975ef0b4f0d9b85dce9d5ccde1
Author: Volker Sobek <reklov live com>
Date:   Wed Sep 12 17:14:31 2012 -0400

    toolbar: add back button if required when populating
    
    When populating the toolbar for the overview, make sure to add a back
    button if there's an active collection.
    
    The back button currently always takes you to the start page, it does
    not use a stack for navigating nested collections. See bug #680000
    for that.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=680001

 src/mainToolbar.js |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/mainToolbar.js b/src/mainToolbar.js
index e1eb8e4..1883c94 100644
--- a/src/mainToolbar.js
+++ b/src/mainToolbar.js
@@ -218,7 +218,7 @@ const OverviewToolbar = new Lang.Class({
                                                Lang.bind(this, this._setToolbarTitle));
     },
 
-    _onActiveCollectionChanged: function() {
+    _checkCollectionBackButton: function() {
         let item = Global.collectionManager.getActiveItem();
 
         if (item && !this._collBackButton) {
@@ -232,12 +232,16 @@ const OverviewToolbar = new Lang.Class({
             this._collBackButton.destroy();
             this._collBackButton = null;
         }
+    },
 
+    _onActiveCollectionChanged: function() {
+        this._checkCollectionBackButton();
         this._setToolbarTitle();
         Global.application.change_action_state('search', GLib.Variant.new('b', false));
     },
 
     _populateForOverview: function() {
+        this._checkCollectionBackButton();
         this.addSearchButton();
 
         let selectionButton =