Comment 13 for bug 522637

I've started actively working on this. Unsurprisingly it looks like a bad interaction with stacking.

Specifically for the lp:do example, there are multiple inventories in the stream from the stacked-on branch with a parent_id_basename_to_file_id root key of sha1:576fa262710cb8cadf998f50c33f4fa28ac6f57b, but that key is apparently being filtered out due to also being the parent_id_basename_to_file_id root key of an inventory at the edge of ancestry.