fix crash at startup caused by use of null session ptr to set end marker (from 2.0)

git-svn-id: svn://localhost/ardour2/branches/3.0@3975 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 8 insertions, 2 deletions

diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index 9d1938c2d2..7b5685858d 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -1169,6 +1169,10 @@ Editor::center_screen_internal (nframes64_t frame, float page)
 void
 Editor::handle_new_duration ()
 {
+	if (!session) {
+		return;
+	}
+
 	ENSURE_GUI_THREAD (mem_fun (*this, &Editor::handle_new_duration));
 
 	nframes64_t new_end = session->get_maximum_extent() + (nframes64_t) floorf (current_page_frames() * 0.10f);
@@ -1176,6 +1180,7 @@ Editor::handle_new_duration ()
 	if (new_end > last_canvas_frame) {
 		last_canvas_frame = new_end;
 		horizontal_adjustment.set_upper (last_canvas_frame / frames_per_unit);
+		horizontal_adjustment.set_page_size (current_page_frames()/frames_per_unit);
 		//reset_scrolling_region ();
 	}
 
@@ -1324,6 +1329,7 @@ Editor::connect_to_session (Session *t)
 		sfbrowser->set_session (session);
 	}
 
+	last_canvas_frame = 0; // force update in handle_new_duration()
 	handle_new_duration ();
 
 	redisplay_regions ();
diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index b1f7f376fb..a1930e58d7 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -342,8 +342,8 @@ Editor::track_canvas_size_allocated ()
 		}
 		
 	}
-	horizontal_adjustment.set_upper (session->current_end_frame()/frames_per_unit);
-	horizontal_adjustment.set_page_size (current_page_frames()/frames_per_unit);
+
+	handle_new_duration ();
 	reset_hscrollbar_stepping ();
 	update_fixed_rulers();
 	redisplay_tempo (false);