tests/test-merge10.t

rust-dirstate: call rust dirstatemap from Python

Since Rust-backed Python classes cannot be used as baseclasses (for
rust-cpython anyway), we use composition rather than inheritance.

This also allows us to keep the IO operations in the Python side, removing
(for now) the need to rewrite VFS in Rust, which would be a heavy undertaking.

Differential Revision: https://phab.mercurial-scm.org/D6634

Test for changeset 9fe267f77f56ff127cf7e65dc15dd9de71ce8ceb
(merge correctly when all the files in a directory are moved
but then local changes are added in the same directory)

  $ hg init a
  $ cd a
  $ mkdir -p testdir
  $ echo a > testdir/a
  $ hg add testdir/a
  $ hg commit -m a
  $ cd ..

  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd a
  $ echo alpha > testdir/a
  $ hg commit -m remote-change
  $ cd ..

  $ cd b
  $ mkdir testdir/subdir
  $ hg mv testdir/a testdir/subdir/a
  $ hg commit -m move
  $ mkdir newdir
  $ echo beta > newdir/beta
  $ hg add newdir/beta
  $ hg commit -m local-addition
  $ hg pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets cc7000b01af9
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up -C 2
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
Abuse this test for also testing that merge respects ui.relative-paths
  $ hg --cwd testdir merge --config ui.relative-paths=yes
  merging subdir/a and a to subdir/a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg stat
  M testdir/subdir/a
  $ hg diff --nodates
  diff -r bc21c9773bfa testdir/subdir/a
  --- a/testdir/subdir/a
  +++ b/testdir/subdir/a
  @@ -1,1 +1,1 @@
  -a
  +alpha

  $ cd ..