[pitivi] Fix backtraces when loading a project with missing assets

[Alexandru Băluț <alexbalut src gnome org>]

commit bcd6932a318454ff49cb1bfe25ab814a992a6c67
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Wed Feb 17 02:07:27 2016 +0100

    Fix backtraces when loading a project with missing assets
    
    Differential Revision: https://phabricator.freedesktop.org/D784

 pitivi/application.py |    8 ++++++--
 pitivi/mainwindow.py  |    5 +++--
 pitivi/project.py     |   13 ++++++++-----
 3 files changed, 17 insertions(+), 9 deletions(-)
---
diff --git a/pitivi/application.py b/pitivi/application.py
index 3080f22..c89f0d9 100644
--- a/pitivi/application.py
+++ b/pitivi/application.py
@@ -271,8 +271,9 @@ class Pitivi(Gtk.Application, Loggable):
         self.project_log_observer.startObserving(project)
 
     def _projectClosed(self, unused_project_manager, project):
-        self.project_log_observer.stopObserving(project)
-        self.timeline_log_observer.stopObserving(project.timeline)
+        if project.loaded:
+            self.project_log_observer.stopObserving(project)
+            self.timeline_log_observer.stopObserving(project.timeline)
 
         if self._scenario_file:
             self.write_action("stop")
@@ -370,6 +371,9 @@ class Pitivi(Gtk.Application, Loggable):
         can_redo = bool(action_log.redo_stacks)
         self.redo_action.set_enabled(can_redo)
 
+        if not self.project_manager.current_project:
+            return
+
         dirty = action_log.dirty()
         self.project_manager.current_project.setModificationState(dirty)
         # In the tests we do not want to create any gui
diff --git a/pitivi/mainwindow.py b/pitivi/mainwindow.py
index 2675b94..7fb2025 100644
--- a/pitivi/mainwindow.py
+++ b/pitivi/mainwindow.py
@@ -860,7 +860,8 @@ class PitiviMainWindow(Gtk.ApplicationWindow, Loggable):
 
         self.info("Project closed")
         self.updateTitle()
-        self._disconnectFromProject(project)
+        if project.loaded:
+            self._disconnectFromProject(project)
         self.timeline_ui.setProject(None)
         self.render_button.set_sensitive(False)
         return False
@@ -906,7 +907,6 @@ class PitiviMainWindow(Gtk.ApplicationWindow, Loggable):
             return None
 
         uri = asset.get_id()
-        new_uri = None
         dialog = Gtk.Dialog(title=_("Locate missing file..."),
                             transient_for=self,
                             modal=True)
@@ -984,6 +984,7 @@ class PitiviMainWindow(Gtk.ApplicationWindow, Loggable):
         dialog.set_default_size(1024, 1000)
         response = dialog.run()
 
+        new_uri = None
         if response == Gtk.ResponseType.OK:
             self.log("User chose a new URI for the missing file")
             new_uri = chooser.get_uri()
diff --git a/pitivi/project.py b/pitivi/project.py
index 661000f..34b3337 100644
--- a/pitivi/project.py
+++ b/pitivi/project.py
@@ -679,14 +679,14 @@ class ProjectManager(GObject.Object, Loggable):
         new_uri = self.emit("missing-uri", project, error, asset)
         if not new_uri:
             project.at_least_one_asset_missing = True
-        self.current_project.setModificationState(True)
+        project.setModificationState(True)
         return new_uri
 
-    def _projectLoadedCb(self, unused_project, unused_timeline):
-        self.debug("Project loaded %s", self.current_project.props.uri)
-        self.emit("new-project-loaded", self.current_project)
+    def _projectLoadedCb(self, project, unused_timeline):
+        self.debug("Project loaded %s", project.props.uri)
         if self.__missing_uris:
-            self.current_project.setModificationState(True)
+            return
+        self.emit("new-project-loaded", project)
         self.time_loaded = time.time()
 
 
@@ -1219,6 +1219,9 @@ class Project(Loggable, GES.Project):
     def do_loaded(self, unused_timeline):
         """ vmethod, get called on "loaded" """
 
+        if not self.timeline:
+            return
+
         self._ensureTracks()
         self.timeline.props.auto_transition = True
         self._ensureLayer()