[f-spot/FSPOT_0_6_0_STABLE] ignores drag-begins if glass is not visible

[Stephane Delcroix <sdelcroix src gnome org>]

commit 6e4d605a13d072168e135d4e3d4d4afa8a7a749b
Author: Mike Gemuende <mike gemuende de>
Date:   Wed Nov 4 17:19:01 2009 +0100

    ignores drag-begins if glass is not visible
    
    The glass of the timeselector was sensitive to drags, even if it
    was not drawn. This caused crashes on an empty database, when
    one clicked to the position the glass really (but invisible) is.
    Now the glass ignores such drags.
    
    fixes bgo #566977

 src/GroupSelector.cs |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/GroupSelector.cs b/src/GroupSelector.cs
index 26cdf48..fbaf8c9 100644
--- a/src/GroupSelector.cs
+++ b/src/GroupSelector.cs
@@ -710,6 +710,9 @@ namespace FSpot {
 
 			public override void StartDrag (double x, double y, uint time)
 			{
+				if (!PositionValid (Position))
+					return;
+
 				base.StartDrag (x, y, time);
 				popup_label.Text = selector.Adaptor.GlassLabel (this.Position);
 				popup_window.Show ();