in_forward: clear out_tag before using(#4670)
@@ -381,6 +381,7 @@ int fw_prot_process(struct fw_conn *conn)
stag_len = tag.via.str.size;
/* Copy the tag to the new buffer, prefix it if required */
+ flb_sds_len_set(out_tag, 0); /* clear out_tag before using */
if (ctx->tag_prefix) {
flb_sds_cat_safe(&out_tag,
ctx->tag_prefix, flb_sds_len(ctx->tag_prefix));
