rebase: small refactoring to allow better extensibility from extensions
Inhibit, one of evolve's extension, would like to change the way rebase works
with obsolete changesets. During a rebase with inhibit, the inhibition of the
obsolescence markers should be lifted for the rebase.
With this small refactoring, inhibit and can wrap the _filterobsoleterevs
function to lift inhibition cleanly and at the same time this change makes
rebases' code more legible.
Ancestors of 5
4 2 0
Ancestors of 6 and 5
3 4 2 1 0
Ancestors of 5 and 4
4 2 0
Ancestors of 7, stop at 6
6
Ancestors of 7, including revs
7 6 5 3 4 2 1 0
Ancestors of 7, 5 and 3, including revs
7 5 3 6 4 2 1 0
Descendants of 5
7 8
Descendants of 5 and 3
6 7 8
Descendants of 5 and 4
5 7 8