t7001: add test case for --dry-run

Make sure that "git mv --dry-run" does not move file.

Signed-off-by: Stefan Moch <stefanmoch@mail.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7001-mv.sh

@@ -38,6 +38,12 @@ test_expect_success \
     'git diff-tree -r -M --name-status  HEAD^ HEAD | \
     grep "^R100..*path1/COPYING..*path0/COPYING"'
 
+test_expect_success \
+    'mv --dry-run does not move file' \
+    'git mv -n path0/COPYING MOVED &&
+     test -f path0/COPYING &&
+     test ! -f MOVED'
+
 test_expect_success \
     'checking -k on non-existing file' \
     'git mv -k idontexist path0'