Bug 2890 - OpenGLESSample-GameView application throws Fatal Unhandled exception on application close in simulator
Summary: OpenGLESSample-GameView application throws Fatal Unhandled exception on appli...
Alias: None
Product: iOS
Classification: Xamarin
Component: XI runtime ()
Version: 5.0
Hardware: Macintosh Mac OS
: Highest critical
Target Milestone: Untriaged
Assignee: Rolf Bjarne Kvinge [MSFT]
Depends on:
Reported: 2012-01-13 12:20 UTC by lindsey.driscoll
Modified: 2014-01-24 09:43 UTC (History)
6 users (show)

Is this bug a regression?: ---
Last known good build:

Fatal Unhandled exception (3.31 KB, text/plain)
2012-01-13 12:20 UTC, lindsey.driscoll

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Description lindsey.driscoll 2012-01-13 12:20:03 UTC
Created attachment 1188 [details]
Fatal Unhandled exception

Fatal Unhandled exception thrown when clicking the home button in the iPhone simulator to exit the application.

Screencast: http://screencast.com/t/PkYwQlY0r

Steps to reproduce:

1. Open the OpenGLESSample-GameView sample application in MonoDevelop
2. Run the application in the iPhone simulator through MD
3. Wait for view to load
- Should see a spinning colorful square
4. Click the iPhone home button to exit the application

Actual result:

Application output indicates FATAL UNHANDLED exception occurs (see attachment)

Expected result:

Should not have a FATAL UNHANDLED exception when exiting program through home button click


Macosx Lion
MonoDevelop: 2.8.6
MonoTouch: 5.1.2
Mono: 2.10.8
Comment 1 lindsey.driscoll 2012-01-13 13:37:23 UTC
Note: This problem did not exist in the previous stable release of MT (5.0.4)
Comment 2 Sebastien Pouliot 2012-01-13 15:17:59 UTC
I can't duplicate it - at least no exactly like this*. Can you reliably reproduce it ? or maybe the app was interrupted in a weird place ?

* When I click on the simulator home button the application quits but I don't get the exception shown in MonoDevelop. OTOH MonoDevelop** does not stop (it still believe it's debugging the app) and I have to stop it manually (that seems consistent with other applications, I don't often use the home button with the simulator ;-).

** I'm using MonoDevelop 2.8.5 (on Lion) so this might explain the difference.
Comment 3 Sebastien Pouliot 2012-01-13 15:44:50 UTC
I used the wrong sample -> OpenGLESSample-GameView
Comment 4 Sebastien Pouliot 2012-01-13 16:10:29 UTC
This null check will avoid the exception - but maybe we should have our own GetContext implementation ? 

diff --git a/Source/OpenTK/Graphics/GraphicsContext.cs b/Source/OpenTK/Graphics/GraphicsContext.cs
index f62d29a..501d445 100644
--- a/Source/OpenTK/Graphics/GraphicsContext.cs
+++ b/Source/OpenTK/Graphics/GraphicsContext.cs
@@ -300,7 +300,7 @@ namespace OpenTK.Graphics
             foreach (WeakReference weak_ref in available_contexts.Values)
                 IGraphicsContext context = (IGraphicsContext)weak_ref.Target;
-                if (context.IsCurrent)
+                if (context != null && context.IsCurrent)
                     return (context as IGraphicsContextInternal).Context;
Comment 5 Miguel de Icaza [MSFT] 2012-01-13 16:20:00 UTC
Adding Rolf to this one, since this is OpenTK related.
Comment 6 Rolf Bjarne Kvinge [MSFT] 2012-01-13 21:41:24 UTC
Fixed in 8a3c1b2e.
Comment 7 narayanp 2014-01-24 09:43:15 UTC
I have checked this issue with following builds:

All Mac
X.S 4.2.3(build 154)
Mono 3.2.6
X.iOS 7.0.7-64

Now I am not seeing crash, Cube appears on simulator. This is the screencast for the same: http://screencast.com/t/Zicn9VyriGV