format.c: Return an empty buffer for empty format strings rather than NULL.

diff --git a/format.c b/format.c
index 37bb087ba02fff7f472d14b0739e715626263c26..02edf37aaf15f27154fd1cefbb7c02515f7b3ba2 100644 (file)
--- a/format.c
+++ b/format.c
@@ -457,5 +457,7 @@ char *format_items(struct format_info *info, union atom_value *values)
                buf = adu_strcat(buf, val);
                free(val);
        }
+       if (!buf)
+               buf = adu_strdup("");
        return buf;
 }