$OpenBSD: patch-ode_demo_demo_piston_cpp,v 1.1 2018/04/07 07:55:14 espie Exp $

Index: ode/demo/demo_piston.cpp
--- ode/demo/demo_piston.cpp.orig
+++ ode/demo/demo_piston.cpp
@@ -659,7 +659,7 @@ int main (int argc, char **argv)
                 {
                     int j = i+1;
                     if ( j+1 > argc      ||  // Check if we have enough arguments
-                            argv[j] == '\0' ||  // We should have a path here
+                            argv[j] == NULL ||  // We should have a path here
                             argv[j][0] == '-' ) // We should have a path not a command line
                         Help (argv);
                     else
