test: testing the double -f comparison

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

test/cli/0010.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+set -e
+
+name=$(basename $0)
+root="$(dirname $(dirname $(dirname $0)))"
+gomtree=$(go run ${root}/test/realpath/main.go ${root}/gomtree)
+t=$(mktemp -d /tmp/go-mtree.XXXXXX)
+
+echo "[${name}] Running in ${t}"
+
+## testing comparing two files
+
+pushd ${root}
+mkdir -p ${t}/extract
+git archive --format=tar HEAD^{tree} . | tar -C ${t}/extract/ -x
+
+${gomtree} -K sha256digest -c -p ${t}/extract/ > ${t}/${name}-1.mtree
+rm -rf ${t}/extract/*.go
+${gomtree} -K sha256digest -c -p ${t}/extract/ > ${t}/${name}-2.mtree
+
+# this _ought_ to fail because the files are missing now
+! ${gomtree} -f ${t}/${name}-1.mtree -f ${t}/${name}-2.mtree
+
+popd
+rm -rf ${t}