added an error check

progs/xdemos/glxdemo.c

@@ -1,4 +1,4 @@
-/* $Id: glxdemo.c,v 1.1 1999/08/19 00:55:43 jtg Exp $ */
+/* $Id: glxdemo.c,v 1.2 2002/04/02 23:53:56 brianp Exp $ */
 
 
 /*
@@ -11,8 +11,11 @@
 
 /*
  * $Log: glxdemo.c,v $
- * Revision 1.1  1999/08/19 00:55:43  jtg
- * Initial revision
+ * Revision 1.2  2002/04/02 23:53:56  brianp
+ * added an error check
+ *
+ * Revision 1.1.1.1  1999/08/19 00:55:43  jtg
+ * Imported sources
  *
  * Revision 3.0  1998/02/21 02:16:54  brianp
  * initial rev
@@ -90,6 +93,10 @@ static Window make_rgb_db_window( Display *dpy,
 		        visinfo->visual, mask, &attr );
 
    ctx = glXCreateContext( dpy, visinfo, NULL, True );
+   if (!ctx) {
+      printf("Error: glXCreateContext failed\n");
+      exit(1);
+   }
 
    glXMakeCurrent( dpy, win, ctx );