Better way to deal with diff vs. cmp and diff options.

configure.ac

@@ -15,7 +15,7 @@ dnl along with this program; if not, write to the Free Software
 dnl Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 dnl 02111-1307, USA.
 
-AC_REVISION([$Id: configure.ac,v 1.26 2003/06/08 12:33:37 rocky Exp $])dnl
+AC_REVISION([$Id: configure.ac,v 1.27 2003/06/08 13:08:37 rocky Exp $])dnl
 AC_INIT(lib/cdio.c)
 AM_CONFIG_HEADER(config.h)
 AM_INIT_AUTOMAKE(libcdio, 0.61)
@@ -54,11 +54,28 @@ else
   unset warning_flags
 fi
 
-dnl We use a perl for documentation and regression tests
+dnl We use a Perl for documentation and regression tests
 AC_PATH_PROG(PERL, perl, no)
-AC_SUBST(PERL)dnl
+AC_SUBST(PERL)
-AC_PATH_PROGS(DIFF, diff, cmp)
+
-AC_SUBST(DIFF)dnl
+dnl We use a diff in regression testing
+AC_PATH_PROG(DIFF, diff, no)
+DIFF_OPTS=
+
+if test "$DIFF" == no ; then
+   AC_PATH_PROG(DIFF, cmp, no)
+else 
+   dnl Try for GNU diff options.
+  # MSDOG output uses \r\n rather than \n in tests
+  for diff_opt in -w --unified ; do 
+    if $DIFF $diff_opt ./configure ./configure > /dev/null 2>&1; then
+      AC_MSG_RESULT([adding $diff_opt to diff in regression tests])
+      DIFF_OPTS="$DIFF_OPTS $diff_opt"
+    fi
+  done
+fi
+AC_SUBST(DIFF)
+AC_SUBST(DIFF_OPTS)
 
 
 AM_PATH_LIBPOPT(, [enable_cdinfo=no])

test/check_common_fn.in

@@ -1,26 +1,5 @@
-# $Id: check_common_fn.in,v 1.1 2003/06/08 12:33:38 rocky Exp $
+# $Id: check_common_fn.in,v 1.2 2003/06/08 13:08:37 rocky Exp $
 SKIP_TEST_EXITCODE=77
-DIFF_OPTS=
-have_diff() {
-  if @DIFF@ ./Makefile ./Makefile > /dev/null 2>&1; then
-    :
-  else
-    
-    return 1;
-  fi
-  
-  if @DIFF@ ./Makefile ./check_common_fn.in > /dev/null 2>&1; then
-    return 1;
-  fi
-
-  # MSDOG output uses \r\n rather than \n in tests
-  for diff_opt in -w --unified ; do 
-    if @DIFF@ $opt ./Makefile ./Makefile > /dev/null 2>&1; then
-      DIFF_OPTS="$DIFF_OPTS $diff_opt"
-    fi
-  done
-  return 0;
-}
 
 check_result() {
   RC=$1
@@ -52,8 +31,8 @@ test_cdinfo() {
   fi
 
   if ${CDINFO} --no-header ${opts} >${outfile} 2>&1 ; then 
-    if have_diff; then
+    if test "@DIFF@" != no; then
-      if @DIFF@ ${outfile} ${rightfile} ; then
+      if @DIFF@ @DIFF_OPTS@ ${outfile} ${rightfile} ; then
 	rm -f $outfile
 	return 0
       else