[gtk+/gtk-3-16] glarea: Check that the context is not NULL

[Emmanuele Bassi <ebassi src gnome org>]

commit f72db440b564098c7c9297bf1390c136e22b4e68
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Mar 25 15:19:30 2015 +0000

    glarea: Check that the context is not NULL
    
    The public API should perform more checks when it comes to an NULL
    context.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746746

 gtk/gtkglarea.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkglarea.c b/gtk/gtkglarea.c
index 1936a7b..90ab9fc 100644
--- a/gtk/gtkglarea.c
+++ b/gtk/gtkglarea.c
@@ -448,6 +448,11 @@ gtk_gl_area_attach_buffers (GtkGLArea *area)
 {
   GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
 
+  g_return_if_fail (GTK_IS_GL_AREA (area));
+
+  if (priv->context == NULL)
+    return;
+
   gtk_gl_area_make_current (area);
 
   if (!priv->have_buffers)
@@ -631,6 +636,9 @@ gtk_gl_area_draw (GtkWidget *widget,
       return FALSE;
     }
 
+  if (priv->context == NULL)
+    return FALSE;
+
   gtk_gl_area_make_current (area);
 
   gtk_gl_area_attach_buffers (area);
@@ -1301,6 +1309,6 @@ gtk_gl_area_make_current (GtkGLArea *area)
 
   g_return_if_fail (gtk_widget_get_realized (widget));
 
-  if (priv->context)
+  if (priv->context != NULL)
     gdk_gl_context_make_current (priv->context);
 }