Minimise duplicate calls to CairoWidget::set_dirty() in the editor summary.

	- many regions may be changed by one operation.

diff --git a/gtk2_ardour/editor_summary.cc b/gtk2_ardour/editor_summary.cc
index 0ac2cdc114ae0653ecf30f97d67e39359fef3170..a2882a201a25a1fbc9aea895fc0b52b39abd7f02 100644 (file)
--- a/gtk2_ardour/editor_summary.cc
+++ b/gtk2_ardour/editor_summary.cc
@@ -293,8 +293,10 @@ EditorSummary::render_region (RegionView* r, cairo_t* cr, double y) const
 void
 EditorSummary::set_background_dirty ()
 {
-       _background_dirty = true;
-       set_dirty ();
+       if (!_background_dirty) {
+               _background_dirty = true;
+               set_dirty ();
+       }
 }
 
 /** Set the summary so that just the overlays (viewbox, playhead etc.) will be re-rendered */