From 10112da9764f80cef4d6e021aa72f1b2034c232f Mon Sep 17 00:00:00 2001
From: Fraser <frassle@gmail.com>
Date: Fri, 21 Feb 2014 19:46:13 +0000
Subject: [PATCH] Respond to WM_SETCURSOR messages.

Calling SetCursor on mouse moves is not enough, we need to respond to
SETCURSOR messages. If we have a custom cursor we need to call SetCursor
and then NOT call DefWindowProc, otherwise we just call DefWindowProc
for the forms default cursor.
---
 Source/OpenTK/Platform/Windows/WinGLNative.cs | 32 +++++++++++++++----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/Source/OpenTK/Platform/Windows/WinGLNative.cs b/Source/OpenTK/Platform/Windows/WinGLNative.cs
index 6fc532d1..5e41c25d 100644
--- a/Source/OpenTK/Platform/Windows/WinGLNative.cs
+++ b/Source/OpenTK/Platform/Windows/WinGLNative.cs
@@ -388,6 +388,17 @@ namespace OpenTK.Platform.Windows
             }
         }
 
+        private bool HandleSetCursor(IntPtr handle, WindowMessage message, IntPtr wParam, IntPtr lParam)
+        {
+            if (cursor != MouseCursor.Default)
+            {
+                Functions.SetCursor(curson_handle);
+                return true;
+            }
+
+            return false;
+        }
+
         void HandleChar(IntPtr handle, WindowMessage message, IntPtr wParam, IntPtr lParam)
         {
             char c;
@@ -486,11 +497,6 @@ namespace OpenTK.Platform.Windows
                 mouse_last_timestamp = timestamp;
             }
 
-            if (cursor != MouseCursor.Default)
-            {
-                Functions.SetCursor(curson_handle);
-            }
-
             if (mouse_outside_window)
             {
                 // Once we receive a mouse move event, it means that the mouse has
@@ -660,6 +666,8 @@ namespace OpenTK.Platform.Windows
 
         IntPtr WindowProcedure(IntPtr handle, WindowMessage message, IntPtr wParam, IntPtr lParam)
         {
+            bool result = false;
+
             switch (message)
             {
                 #region Size / Move / Style events
@@ -693,6 +701,10 @@ namespace OpenTK.Platform.Windows
                     HandleSize(handle, message, wParam, lParam);
                     break;
 
+                case WindowMessage.SETCURSOR:
+                    result = HandleSetCursor(handle, message, wParam, lParam);
+                    break;
+
                 #endregion
 
                 #region Input events
@@ -779,7 +791,15 @@ namespace OpenTK.Platform.Windows
                 #endregion
             }
 
-            return Functions.DefWindowProc(handle, message, wParam, lParam);
+            if (result)
+            {
+                // Return TRUE
+                return new IntPtr(1);
+            }
+            else
+            {
+                return Functions.DefWindowProc(handle, message, wParam, lParam);
+            }
         }
 
         private void EnableMouseTracking()