Index: Makefile.in
--- Makefile.in.orig	2005-06-13 19:41:01 +0200
+++ Makefile.in	2007-01-06 14:18:07 +0100
@@ -113,7 +113,7 @@
 
 bin_PROGRAMS = src/interdiff src/filterdiff src/rediff
 bin_SCRIPTS = fixcvsdiff splitdiff editdiff recountdiff unwrapdiff dehtmldiff \
-	espdiff
+	espdiff gendiff
 
 man_MANS = doc/interdiff.1 doc/filterdiff.1 doc/fixcvsdiff.1 doc/rediff.1 \
 	doc/editdiff.1 doc/combinediff.1 doc/lsdiff.1 doc/splitdiff.1 \
@@ -513,6 +513,8 @@
 	cd $(top_builddir) && $(SHELL) ./config.status $@
 espdiff: $(top_builddir)/config.status espdiff.in
 	cd $(top_builddir) && $(SHELL) ./config.status $@
+gendiff: $(top_builddir)/config.status gendiff.in
+	cd $(top_builddir) && $(SHELL) ./config.status $@
 patchutils.spec: $(top_builddir)/config.status patchutils.spec.in
 	cd $(top_builddir) && $(SHELL) ./config.status $@
 binPROGRAMS_INSTALL = $(INSTALL_PROGRAM)
Index: configure
--- configure.orig	2005-06-13 19:41:01 +0200
+++ configure	2007-01-06 14:19:46 +0100
@@ -4879,7 +4879,7 @@
 _ACEOF
 
 
-                                                                                          ac_config_files="$ac_config_files Makefile splitdiff editdiff fixcvsdiff recountdiff unwrapdiff dehtmldiff espdiff patchutils.spec"
+                                                                                          ac_config_files="$ac_config_files Makefile splitdiff editdiff fixcvsdiff recountdiff unwrapdiff dehtmldiff espdiff patchutils.spec gendiff"
 cat >confcache <<\_ACEOF
 # This file is a shell script that caches the results of configure
 # tests run on this system so they can be shared between configure
Index: gendiff.in
--- /dev/null	2007-01-06 14:19:19 +0100
+++ gendiff.in	2007-01-06 14:18:07 +0100
@@ -0,0 +1,18 @@
+#!/bin/bash
+if [ $# -ne 2 ]; then
+    echo "Usage: ${0##*/} DIRECTORY DIFF-SUFFIX" 1>&2
+    exit 1
+fi
+find "$1" \( -name "*$2" -o -name ".*$2" \) -print |\
+while read OP; do
+    NP="${OP%$2}"
+    NN="${NP##*/}"
+    U="-u"
+    if [ "$NN" = "ChangeLog" ]; then
+        U="-U0"
+    fi
+    case "${NN##*.}" in
+        c|cc|C|cpp) U="$U -p" ;;
+    esac
+    diff $U "$OP" "$NP"
+done
Index: src/diff.c
--- src/diff.c.orig	2005-02-27 00:45:20 +0100
+++ src/diff.c	2007-01-06 14:18:07 +0100
@@ -67,16 +67,20 @@
 {
         int *pathname_components;
         int *basename_length;
+	int *is_dev_null;
         int best_pn, best_bn, best_n, best = 0; /* shut gcc up */
         int i;
 
         pathname_components = xmalloc (sizeof (int *) * n);
         basename_length = xmalloc (sizeof (int *) * n);
+        is_dev_null = xmalloc (sizeof (int *) * n);
 
         best_pn = -1;
         for (i = 0; i < n; i++) {
-		if (!strcmp (names[i], "/dev/null"))
+		is_dev_null[i] = !strcmp (names[i], "/dev/null");
+		if (is_dev_null[i])
 			continue;
+
                 pathname_components[i] = num_pathname_components (names[i]);
                 if ((best_pn == -1) ||
                     (pathname_components[i] < best_pn))
@@ -87,7 +91,7 @@
         for (i = 0; i < n; i++) {
                 char *p;
 
-		if (!strcmp (names[i], "/dev/null"))
+		if (is_dev_null[i])
 			continue;
 
                 if (pathname_components[i] != best_pn)
@@ -109,6 +113,9 @@
 	for (i = 0; i < n; i++) {
 		int len;
 
+		if (is_dev_null[i])
+			continue;
+
                 if (basename_length[i] != best_bn)
                         continue;
 
@@ -122,6 +129,7 @@
 
         free (pathname_components);
         free (basename_length);
+        free (is_dev_null);
         return names[best];
 }