workspace: Save window default layout fixes #1769

rn=
     (integrated from master branch change cd705ac by Carey Hoffman (cgchoffman@gmail.com>)

src/chrome/komodo/content/library/widgets.js

@@ -878,6 +878,13 @@ if (typeof(ko.widgets)=='undefined') {
         }
     };
 
+    /**
+     * Save the UI state as JSON string in PrefPath
+     *
+     * @argument {Array} prefpath array of string prefIds, where to save state
+     *                            in prefs.xml.  Empty list saves globaly UI. ie.
+     *                            all new windows will load this state.
+     */                           
     this.unload = function koWidgetManager_onunload(prefpath) {
         // Note that this doesn't use this._persist_state; that's for restoring
         // only, we want to record the state as it is now

src/chrome/komodo/content/workspace.p.js

@@ -642,7 +642,12 @@ this.saveWorkspace = function view_saveWorkspace(saveNow)
                                           windowWorkspace, saveCoordinates);
         }
         // Use the current window's layout as the default for new windows
-        mainWindow.ko.widgets.unload(require("ko/prefs"),[]);
+        // Use the last window to close to save the default window state
+        // Don't run this everytime saveWorkspace is run (eg. on every file
+        // open)
+        if(ko.windowManager.lastWindow()){
+            ko.widgets.unload([]);
+        }
         var prefSvc = Components.classes["@activestate.com/koPrefService;1"].getService(Components.interfaces.koIPrefService);
         if (saveNow) {
             prefSvc.saveState();