git-svn: add the commit-diff command

This is intended for interoperability with git-svnimport.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/contrib/git-svn/t/t0005-commit-diff.sh b/contrib/git-svn/t/t0005-commit-diff.sh
new file mode 100644
index 0000000..f994b72
--- /dev/null
+++ b/contrib/git-svn/t/t0005-commit-diff.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Eric Wong
+test_description='git-svn commit-diff'
+. ./lib-git-svn.sh
+
+if test -n "$GIT_SVN_NO_LIB" && test "$GIT_SVN_NO_LIB" -ne 0
+then
+	echo 'Skipping: commit-diff needs SVN libraries'
+	test_done
+	exit 0
+fi
+
+test_expect_success 'initialize repo' "
+	mkdir import &&
+	cd import &&
+	echo hello > readme &&
+	svn import -m 'initial' . $svnrepo &&
+	cd .. &&
+	echo hello > readme &&
+	git update-index --add readme &&
+	git commit -a -m 'initial' &&
+	echo world >> readme &&
+	git commit -a -m 'another'
+	"
+
+head=`git rev-parse --verify HEAD^0`
+prev=`git rev-parse --verify HEAD^1`
+
+# the internals of the commit-diff command are the same as the regular
+# commit, so only a basic test of functionality is needed since we've
+# already tested commit extensively elsewhere
+
+test_expect_success 'test the commit-diff command' "
+	test -n '$prev' && test -n '$head' &&
+	git-svn commit-diff '$prev' '$head' '$svnrepo' &&
+	svn co $svnrepo wc &&
+	cmp readme wc/readme
+	"
+
+test_done