Merge rust-bitcoin#4964: bip158: Return no match for empty query

e7d992a bip158: Return no match for empty query (rustaceanrob)

Pull request description:

  Perhaps this is up for debate, but considering the use case of checking for inclusions in a block, an empty query should not return `true` for any element, as no elements exist in the query. If the user happens to have no scripts to query for whatever reason, they will think every block is relevant.


ACKs for top commit:
  apoelstra:
    ACK e7d992a; successfully ran local tests
  tcharding:
    ACK e7d992a


Tree-SHA512: a67b40d315edbd5bfdd569558fdf2259717a00772b607a663cd77ae86d1af0a302d74c629c438a0aae5f8227fbd9ddb838fdb0c969afabd9ac90e638dd6d2f10

Author: apoelstra

bitcoin/src/bip158.rs

@@ -306,7 +306,7 @@ impl GcsFilterReader {
         // sort
         mapped.sort_unstable();
         if mapped.is_empty() {
-            return Ok(true);
+            return Ok(false);
         }
         if n_elements == 0 {
             return Ok(false);