rebase: filter out descendants of divergence-causing commits earlier...
rebase: filter out descendants of divergence-causing commits earlier
`hg rebase` treats obsolete commits differently depending what has
happened to the commit:
1) Obsolete commit without non-obsolete successors: Skipped, and a
note is printed ("it has no successor").
2) Obsolete commit with a successor in the destination (ancestor of
it): Skipped, and a note is printed ("already in destination").
3) Obsolete commit with a successor in the rebase set: The commit and
its descendants are skipped, and a note is printed ("not rebasing
<commit> and its descendants as this would cause divergence"), unless
`allowdivergence` config set.
4) Obsolete commit with a successor elsewhere: Error ("this rebase
will cause divergences"), unless `allowdivergence` config set.
Before this patch, we did all those checks up front, except for (3),
which was checked later. The later check consisted of two parts: 1)
filtering out of descendants, and 2) conditionally printing message if
the `allowdivergence` config was not set. This patch makes it so we do
the filtering early.
A consequence of filtering out divergence-causing commits earlier is
that we rebase commits in slightly different order, which has some
impact on tests.
Differential Revision:
https://phab.mercurial-scm.org/D10249
