[PATCH] builtin/tag.c: return appropriate value when --points-at finds an empty list

[George Papanikolaou]

`git tag --points-at` can simply return if the given rev does not have
any tags pointing to it. It's not a failure but it shouldn't return
with 0 value.
---
 builtin/tag.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/builtin/tag.c b/builtin/tag.c
index b38329b59..68b84db2a 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -58,6 +58,10 @@ static int list_tags(struct ref_filter *filter, struct 
ref_sorting *sorting,
                die(_("unable to parse format string"));
        filter->with_commit_tag_algo = 1;
        filter_refs(&array, filter, FILTER_REFS_TAGS);
+
+       if (array.nr == 0)
+               return -1;
+
        ref_array_sort(sorting, &array);
 
        for (i = 0; i < array.nr; i++)
-- 
2.11.0