[chronojump] Fixed crash on 1st jumpsFrofile drawn since recent commits

[Xavier de Blas <xaviblas src gnome org>]

commit 61147f78e67bdbfbbcd02746558ef1664078bcc0
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Jan 7 18:15:07 2020 +0100

    Fixed crash on 1st jumpsFrofile drawn since recent commits

 src/gui/app1/jumpsProfile.cs  | 2 +-
 src/gui/cairo/jumpsProfile.cs | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/gui/app1/jumpsProfile.cs b/src/gui/app1/jumpsProfile.cs
index 5877ea4f..9cec24ad 100644
--- a/src/gui/app1/jumpsProfile.cs
+++ b/src/gui/app1/jumpsProfile.cs
@@ -49,7 +49,7 @@ public partial class ChronoJumpWindow
        private void jumpsProfileDo (bool calculateData)
        {
                if(currentPerson == null || currentSession == null ||
-                               drawingarea_jumps_profile == null) //it happens at start on click on analyze
+                               drawingarea_jumps_profile == null || drawingarea_jumps_profile.GdkWindow == 
null) //it happens at start on click on analyze
                        return;
                
                if(jumpsProfile == null) {
diff --git a/src/gui/cairo/jumpsProfile.cs b/src/gui/cairo/jumpsProfile.cs
index da4e94f1..9f678777 100644
--- a/src/gui/cairo/jumpsProfile.cs
+++ b/src/gui/cairo/jumpsProfile.cs
@@ -56,6 +56,8 @@ public static class JumpsProfileGraph
        public static void Do (List<JumpsProfileIndex> l_jpi, DrawingArea area, string title, string date)
        {
                //LogB.Information(string.Format("is area null: {0}", (area == null)));
+               //LogB.Information(string.Format("is area.GdkWindow null: {0}", (area.GdkWindow == null)));
+
                //1 create context
                Cairo.Context g = Gdk.CairoHelper.Create (area.GdkWindow);