diff --git a/lib/driver/disc.c b/lib/driver/disc.c
index 3c66ea95..ec09ad10 100644
--- a/lib/driver/disc.c
+++ b/lib/driver/disc.c
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2003, 2004, 2005, 2008, 2011
+  Copyright (C) 2003, 2004, 2005, 2008, 2011, 2012
    Rocky Bernstein <rocky@gnu.org>
   Copyright (C) 2001 Herbert Valerio Riedel <hvr@gnu.org>
 
@@ -124,7 +124,7 @@ cdio_get_discmode (CdIo_t *cd_obj)
 char *
 cdio_get_mcn (const CdIo_t *p_cdio) 
 {
-  if (p_cdio->op.get_mcn) {
+  if (p_cdio && p_cdio->op.get_mcn) {
     return p_cdio->op.get_mcn (p_cdio->env);
   } else {
     return NULL;
diff --git a/test/driver/.gitignore b/test/driver/.gitignore
index 0c5a2ffa..50828daa 100644
--- a/test/driver/.gitignore
+++ b/test/driver/.gitignore
@@ -9,6 +9,7 @@
 /bincue
 /bincue
 /bincue.c
+/cdda
 /cdrdao
 /cdrdao.c
 /follow_symlink
diff --git a/test/driver/Makefile.am b/test/driver/Makefile.am
index 6f8b12c0..b55ab70d 100644
--- a/test/driver/Makefile.am
+++ b/test/driver/Makefile.am
@@ -24,6 +24,10 @@ bincue_SOURCES   = helper.c bincue.c
 bincue_LDADD     = $(LIBCDIO_LIBS) $(LTLIBICONV)
 bincue_CFLAGS    = -DDATA_DIR=\"$(DATA_DIR)\"
 
+cdda_SOURCES     = helper.c cdda.c
+cdda_LDADD       = $(LIBCDIO_LIBS) $(LTLIBICONV)
+cdda_CFLAGS      = -DDATA_DIR=\"$(DATA_DIR)\"
+
 cdrdao_SOURCES   = helper.c cdrdao.c
 cdrdao_LDADD     = $(LIBCDIO_LIBS) $(LTLIBICONV)
 cdrdao_CFLAGS    = -DDATA_DIR=\"$(DATA_DIR)\"
@@ -58,7 +62,7 @@ win32_LDADD      = $(LIBCDIO_LIBS) $(LTLIBICONV)
 win32_CFLAGS     = -DDATA_DIR=\"$(DATA_DIR)\"
 
 check_PROGRAMS   = \
-	abs_path bincue cdrdao freebsd gnu_linux \
+	abs_path bincue cdda cdrdao freebsd gnu_linux \
 	mmc_read mmc_write nrg \
 	osx realpath solaris win32
 
diff --git a/test/driver/cdda.c b/test/driver/cdda.c
new file mode 100644
index 00000000..6c38245e
--- /dev/null
+++ b/test/driver/cdda.c
@@ -0,0 +1,56 @@
+/* -*- C -*-
+  Copyright (C) 2012 Rocky Bernstein <rocky@gnu.org>
+  
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* 
+   Unit test for cdda-like things lib/driver/disc.c
+*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+#include "helper.h"
+
+int
+main(int argc, const char *argv[])
+{
+  char *mcn = cdio_get_mcn(NULL);
+  
+  cdio_log_set_handler(log_handler);
+  cdio_loglevel_default = (argc > 1) ? CDIO_LOG_DEBUG : CDIO_LOG_INFO;
+
+  /* Had a bug in not testing for null p_cdio with cdio_get_mcn. */
+  mcn = cdio_get_mcn(NULL);
+  if (mcn != NULL) {
+      printf("Should have gotten NULL for MCN for cdio object\n");
+      return 1;
+  }
+  
+  return 0;
+}
diff --git a/test/driver/gnu_linux.c b/test/driver/gnu_linux.c
index f4571b3e..fabae3fa 100644
--- a/test/driver/gnu_linux.c
+++ b/test/driver/gnu_linux.c
@@ -1,5 +1,5 @@
 /* -*- C -*-
-  Copyright (C) 2009, 2010 Rocky Bernstein <rocky@gnu.org>
+  Copyright (C) 2009, 2010, 2012 Rocky Bernstein <rocky@gnu.org>
   
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -20,7 +20,6 @@
 */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
-#define __CDIO_CONFIG_H__ 1
 #endif
 
 #ifdef HAVE_STDIO_H