Ok, there appears to be a client-side bug in RemoteStreamSource.missing_parents_rev_handler. It appears to require a cross-format fetch with a stacked branch to trigger it. I'm working on a test and fix (I'm a bit surprised the existing explicit tests for stacking + smart server + cross-format fetches aren't triggering it!).
Ok, there appears to be a client-side bug in RemoteStreamSou rce.missing_ parents_ rev_handler. It appears to require a cross-format fetch with a stacked branch to trigger it. I'm working on a test and fix (I'm a bit surprised the existing explicit tests for stacking + smart server + cross-format fetches aren't triggering it!).