[gtk+] gl: Warn the user if they request a GL context version less than 3.2

[Alexander Larsson <alexl src gnome org>]

commit b87715973f43ada48805bd0b22bd83eb4993d315
Author: Niels Nesse <nnesse sonic net>
Date:   Tue Feb 10 20:35:01 2015 -0800

    gl: Warn the user if they request a GL context version less than 3.2
    
    If the user requests a version less than 3.2 the version is forced to 3.2.
    Previous checking code have an inconsistent behavior depending on which
    minor version number was specified. This is avoided now by temporarily
    converting the major/minor pair into a single integer.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=744288

 gdk/gdkglcontext.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
---
diff --git a/gdk/gdkglcontext.c b/gdk/gdkglcontext.c
index 1d88a48..306e0ae 100644
--- a/gdk/gdkglcontext.c
+++ b/gdk/gdkglcontext.c
@@ -492,6 +492,7 @@ gdk_gl_context_set_required_version (GdkGLContext *context,
                                      int           major,
                                      int           minor)
 {
+  int version;
   GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
 
   g_return_if_fail (GDK_IS_GL_CONTEXT (context));
@@ -505,13 +506,15 @@ gdk_gl_context_set_required_version (GdkGLContext *context,
       return;
     }
 
-  priv->major = MAX (major, 3);
-
-  /* we only support versions ≥ 3.2 */
-  if (priv->major == 3)
-    priv->minor = MAX (minor, 2);
-  else
-    priv->minor = minor;
+  /* Enforce a minimum context version number of 3.2 */
+  version = (major * 100) + minor;
+  if (version < 302)
+    {
+      g_warning ("gdk_gl_context_set_required_version - GL context versions less than 3.2 are not 
supported.");
+      version = 302;
+    }
+  priv->major = version / 100;
+  priv->minor = version % 100;
 }
 
 /**