272     allobjects = repo.obsstore.precursors

   272     allobjects = repo.obsstore.precursors

   273     while toproceed:

   273     while toproceed:

   274         nc = toproceed.pop()

   274         nc = toproceed.pop()

   275         for mark in allobjects.get(nc, ()):

   275         for mark in allobjects.get(nc, ()):

   276             for sub in mark[1]:

   276             for sub in mark[1]:

   277                 if sub not in seen:

   279                 if sub not in seen:

   278                     seen.add(sub)

   280                     seen.add(sub)

   279                     toproceed.append(sub)

   281                     toproceed.append(sub)

   280     nm = repo.changelog.nodemap

   282     nm = repo.changelog.nodemap

   281     cs = set()

   283     cs = set()