@@ -639,8 +639,19 @@
  # Route through the shallow walker when shallow args are present,
  # otherwise fall through to the standard full-reachability walk.
  # Objects are then passed through the filter (if any).
  #
  # Promisor lazy-fetch exception: partial-clone clients fill in
  # missing blobs/trees on demand by sending a fetch with the
  # specific object as a `want`. The server MUST return that exact
  # object even if the session-level filter would normally exclude
  # it — the client already knows the SHA and is explicitly asking
  # for it. `lazy_fetch?/2` detects this by peeking at each want's
  # object type: if any want is a non-commit, we treat the request
  # as a lazy fetch and bypass the filter + blob-skip optimization.
  defp collect_objects_maybe_shallow(repo, wants, haves, shallow_opts, filter_spec) do
    lazy? = lazy_fetch?(repo, wants)
    effective_filter = if lazy?, do: nil, else: filter_spec
    walk_opts = %{skip_blobs: not lazy? and early_skip_blobs?(filter_spec)}
    walk_opts = %{skip_blobs: early_skip_blobs?(filter_spec)}
    result =
      case shallow_opts do
@@ -649,8 +660,23 @@
      end
    with {:ok, walk} <- result do
      {:ok, %{walk | objects: apply_filter(walk.objects, effective_filter, repo)}}
      {:ok, %{walk | objects: apply_filter(walk.objects, filter_spec, repo)}}
    end
  end
  # Lazy-fetch heuristic: a fetch whose want-set includes any blob,
  # tree, or tag is the client asking for specific objects by SHA
  # (typically a promisor remote filling in a missing object after a
  # partial clone). Commits-only `wants` are normal reachability
  # fetches and the filter applies as usual.
  defp lazy_fetch?(repo, wants) do
    Enum.any?(wants, fn sha ->
      case ObjectResolver.read(repo, sha) do
        {:ok, %Commit{}} -> false
        {:ok, _other} -> true
        _ -> false
      end
    end)
  end
  # Some filter specs exclude every blob outright. When that's the