Re: commit-message attack for extracting sensitive data from rewritten Git history

Am 4/8/2013 23:54, schrieb Jeff King:

Yeah, it would make sense for filter-branch to have a "--map-commit-ids"
option or similar that does the update. At first I thought it might take
two passes, but I don't think it is necessary, as long as we traverse
the commits topologically (i.e., you cannot have mentioned X in a commit
that is an ancestor of X, so you do not have to worry about mapping it
until after it has been processed).

Topological traversal is not sufficient. Consider this history:

     o--A--o--
    /     /
 --o--B--o

If A mentions B (think of cherry-pick -x), then you must ensure that the
branch containing B was traversed first.

-- Hannes