rust-index: using `hg::index::Index` in `hg-cpython::dagops`
Hooking `headrevs` to the Rust index is straightforward as long as
we go the `PySharedRef` way. Direct attempts of obtaining a reference
to the inner `hg::index::Index` fail for lifetime reasons: the reference
is bound to the GIL, yet the `as_set` local variable is considered to
be static (the borrow checker clearly does not realize or care that this
set only stores `Revision` values).
In `rank()`, the chosen solution is the simplest as far as `hg-cpython` is
concerned, but it has the defect of removing an implementation
that would be easily adaptable if the core index did implement `RankedGraph`
(returning the same error as long as only `REVLOGV1` is supported), but that
would introduce a direct dependency of `hg-core` on the ``vcsgraph` crate.
Just exercise debugindexdot
Create a short file history including a merge.
$ hg init t
$ cd t
$ echo a > a
$ hg ci -qAm t1 -d '0 0'
$ echo a >> a
$ hg ci -m t2 -d '1 0'
$ hg up -qC 0
$ echo b >> a
$ hg ci -m t3 -d '2 0'
created new head
$ HGMERGE=true hg merge -q
$ hg ci -m merge -d '3 0'
$ hg debugindexdot -c
digraph G {
-1 -> 0
0 -> 1
0 -> 2
2 -> 3
1 -> 3
}
$ hg debugindexdot -m
digraph G {
-1 -> 0
0 -> 1
0 -> 2
2 -> 3
1 -> 3
}
$ hg debugindexdot a
digraph G {
-1 -> 0
0 -> 1
0 -> 2
2 -> 3
1 -> 3
}
$ cd ..