store: keys_at tells no map from an empty one

registry::exists counted any value at _continuum/users as a registry;
keys_at answers None where there is no map, and its users (records,
members, forget records, remakes) say what they make of it.

Auth plan M1 (fix).

1 files changed, 2 insertions, 1 deletions

diff --git a/src/remake/snapshot.rs b/src/remake/snapshot.rs
index 157a28d..220989e 100644
--- a/src/remake/snapshot.rs
+++ b/src/remake/snapshot.rs
@@ -231,6 +231,7 @@ pub(crate) fn verify_document(doc: &Document, epoch: Epoch) -> Result<EpochMetad
 pub(crate) fn epoch_of(doc: &Document) -> Result<Epoch, String> {
     let generation = store::keys_at(doc, &meta::path(&[EPOCHS]))
         .map_err(|error| error.to_string())?
+        .unwrap_or_default()
         .iter()
         .filter_map(|key| key.parse::<u64>().ok())
         .max();
@@ -295,7 +296,7 @@ pub(crate) fn build(
         Ok(()) | Err(StoreError::NotFound) => {}
         Err(error) => return Err(error.into()),
     }
-    let mut protocol_keys = store::keys_at(&base, &meta::path(&[]))?;
+    let mut protocol_keys = store::keys_at(&base, &meta::path(&[]))?.unwrap_or_default();
     protocol_keys.sort();
     for key in protocol_keys
         .into_iter()