From 7b795a02e108ad272138a355557865238f0d2b26 Mon Sep 17 00:00:00 2001
From: Jonas Boesch <jonas.boesch@phonak.com>
Date: Tue, 21 Apr 2015 16:08:20 +0200
Subject: [PATCH] Bugfix: Non-null shared contexts for Egl threw Exception

The shared context parameter can be either the EglContext directly, or
the facade, and we cast to see what it is.
---
 src/OpenTK/Platform/Egl/EglContext.cs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/OpenTK/Platform/Egl/EglContext.cs b/src/OpenTK/Platform/Egl/EglContext.cs
index b6cca8f..2844686 100644
--- a/src/OpenTK/Platform/Egl/EglContext.cs
+++ b/src/OpenTK/Platform/Egl/EglContext.cs
@@ -53,6 +53,8 @@ namespace OpenTK.Platform.Egl
             if (window == null)
                 throw new ArgumentNullException("window");
 
+            EglContext shared = GetSharedEglContext(sharedContext);
+
             WindowInfo = window;
 
             // Select an EGLConfig that matches the desired mode. We cannot use the 'mode'
@@ -216,6 +218,21 @@ namespace OpenTK.Platform.Egl
             }
         }
 
+        private EglContext GetSharedEglContext(IGraphicsContext sharedContext)
+        {
+            if (sharedContext == null)
+            {
+                return null;
+            }
+
+            var internalContext = sharedContext as IGraphicsContextInternal;
+            if (internalContext != null)
+            {
+                return (EglContext) internalContext.Implementation;
+            }
+            return (EglContext) sharedContext;
+        }
+
         #endregion
     }
 }
-- 
2.7.4