David Rosenstrauch reported that header files spnegohelp.h and

openssl/objects.h were needed to compile SPNEGO support.

lib/http_negotiate.c

@@ -42,6 +42,15 @@
 #include "http_negotiate.h"
 #include "memory.h"
 
+#ifdef HAVE_SPNEGO
+# include <spnegohelp.h>
+# if defined(USE_OPENSSL) && !defined(USE_YASSLEMUL)
+#  include <openssl/objects.h>
+# else
+#  error "Can't compile SPNEGO support without OpenSSL."
+# endif
+#endif
+
 #define _MPRINTF_REPLACE /* use our functions only */
 #include <curl/mprintf.h>