t7001: add test case for --dry-run

diff --git a/ref-filter.c b/ref-filter.c
index bc591f4f3de0c07b0cfe3813d5d9daaf1ad44b63..f3e53d4448f10ca1002e546890ca682c02ecc9ad 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -415,8 +415,16 @@ static int parse_ref_filter_atom(const struct ref_format *format,
        REALLOC_ARRAY(used_atom, used_atom_cnt);
        used_atom[at].name = xmemdupz(atom, ep - atom);
        used_atom[at].type = valid_atom[i].cmp_type;
-       if (arg)
+       if (arg) {
                arg = used_atom[at].name + (arg - atom) + 1;
+               if (!*arg) {
+                       /*
+                        * Treat empty sub-arguments list as NULL (i.e.,
+                        * "%(atom:)" is equivalent to "%(atom)").
+                        */
+                       arg = NULL;
+               }
+       }
        memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
        if (valid_atom[i].parser)
                valid_atom[i].parser(format, &used_atom[at], arg);