37 

    38 def allprecursors(obsstore, nodes, ignoreflags=0):

    39     """Yield node for every precursors of <nodes>.

    40 

    41     Some precursors may be unknown locally.

    42 

    43     This is a linear yield unsuited to detecting folded changesets. It includes

    44     initial nodes too."""

    45 

    46     remaining = set(nodes)

    47     seen = set(remaining)

    48     while remaining:

    49         current = remaining.pop()

    50         yield current

    51         for mark in obsstore.precursors.get(current, ()):

    52             # ignore marker flagged with specified flag

    53             if mark[2] & ignoreflags:

    54                 continue

    55             suc = mark[0]

    56             if suc not in seen:

    57                 seen.add(suc)

    58                 remaining.add(suc)