Check the glutDisplayFunc() callback for being a NULL pointer. This is

illegal and is disallowed in GLUT 3.0+, so we disallow it too in
freeglut 2.0.1+

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@221 7f0cb862-5218-0410-a997-914c9d46530a

diff --git a/src/freeglut_callbacks.c b/src/freeglut_callbacks.c
index 90baf10..da06283 100644 (file)
--- a/src/freeglut_callbacks.c
+++ b/src/freeglut_callbacks.c
@@ -48,6 +48,9 @@
  */
 void FGAPIENTRY glutDisplayFunc( void (* callback)( void ) )
 {
+    if( !callback )
+       fgError ("Fatal error in program.  NULL display callback not "
+           "permitted in GLUT 3.0+ or freeglut 2.0.1+\n");
     SET_CALLBACK( Display );
 
     /*