histedit: add obsolete support
When the obsolete feature is enabled, histedit creates obsolescence marker
instead of stripping replaced changesets.
For now, we keep stripping temporary nodes created along the way.
histedit: replace various nodes lists with replacement graph (and
issue3582)
This changeset rewrites the change tracking logic of histedit to record every
operation it does. Tracked operations record the full list of "old" node that
will eventually be removed to the list of new nodes that replace it. Operations
on temporary nodes are tracked too. Dropped changesets are also recorded as an
"old" node replacement by nothing. This logic is similar to the obsolescence
marker one and will be used for this purpose in later commit.
This new logic implies a big amount of change in the histedit code base.
histedit action functions now always return a tuple of
(new-ctx, [list of rewriting operations])
The old `created`, `replaced` and `tmpnodes` are no longer returned and stored
during histedit operation. When such information is necessary it is computed
from the replacement graph. This computation is done in the `processreplacement`
function.
The `replacemap` is also dropped. It is computed at the end of the command from the
graph. The `bootstrapcontinue` methods are altered to compute this different kind of
information.
This new mechanism requires much less information to be written on disk.
Note:
This changes allows a more accurate bookmark movement. bookmark on dropped
changeset are now move of their parent (or replacement of their parent)
instead of their children.
This fix
issue3582