linkrev: introduce an 'introrev' method on filectx...
linkrev: introduce an 'introrev' method on filectx
The previous changeset properly fixed the ancestors computation, but we need to
ensure that the initial filectx is also using the right changeset.
When asking for log or annotation from a certain point, the first step is to
define the changeset that introduced the current file version. We cannot just
pick the "starting point" changesets as it may just "use" the file revision,
unchanged.
Currently, we were using 'linkrev' for this purpose, but this exposes us to
unexpected branch-jumping when the revision introducing the starting point
version is itself linkrev-shadowed. So we need to take the topology into
account again. Therefore, we introduce an 'introrev' function, returning the
changeset which introduced the file change in the current changeset.
This function will be used to fix linkrev-related issues when bootstrapping 'hg
log --follow' and 'hg annotate'.
It reuses the '_adjustlinkrev' function, extending it to allow introspection of
the initial changeset too. In the previous usage of the '_adjustlinkrev' the
starting rev was always using a children file revisions, so it could be safely
ignored in the search. In this case, the starting point is using the revision
of the file we are looking, and may be the changeset we are looking for.
