Test another lease edge case.

src/allmydata/storage_client.py

@@ -76,6 +76,7 @@ from allmydata.util.observer import ObserverList
 from allmydata.util.rrefutil import add_version_to_remote_reference
 from allmydata.util.hashutil import permute_server_hash
 from allmydata.util.dictutil import BytesKeyDict, UnicodeKeyDict
+from allmydata.util.deferredutil import async_to_deferred
 from allmydata.storage.http_client import (
     StorageClient, StorageClientImmutables, StorageClientGeneral,
     ClientException as HTTPClientException, StorageClientMutables,
@@ -1166,16 +1167,23 @@ class _HTTPStorageServer(object):
             for share_num in share_numbers
         })
 
-    def add_lease(
+    @async_to_deferred
+    async def add_lease(
         self,
         storage_index,
         renew_secret,
         cancel_secret
     ):
         immutable_client = StorageClientImmutables(self._http_client)
-        return immutable_client.add_or_renew_lease(
-            storage_index, renew_secret, cancel_secret
-        )
+        try:
+            await immutable_client.add_or_renew_lease(
+                storage_index, renew_secret, cancel_secret
+            )
+        except ClientException as e:
+            if e.code == http.NOT_FOUND:
+                # Silently do nothing, as is the case for the Foolscap client
+                return
+            raise
 
     def advise_corrupt_share(
         self,

src/allmydata/test/test_istorageserver.py

@@ -459,6 +459,21 @@ class IStorageServerImmutableAPIsTestsMixin(object):
             lease.get_expiration_time() - self.fake_time() > (31 * 24 * 60 * 60 - 10)
         )
 
+    @inlineCallbacks
+    def test_add_lease_non_existent(self):
+        """
+        If the storage index doesn't exist, adding the lease silently does nothing.
+        """
+        storage_index = new_storage_index()
+        self.assertEqual(list(self.server.get_leases(storage_index)), [])
+
+        renew_secret = new_secret()
+        cancel_secret = new_secret()
+
+        # Add a lease:
+        yield self.storage_client.add_lease(storage_index, renew_secret, cancel_secret)
+        self.assertEqual(list(self.server.get_leases(storage_index)), [])
+
     @inlineCallbacks
     def test_add_lease_renewal(self):
         """