view tests/test-issue522.t @ 51619:b08c5fbe0e70 stable

rust: blanket implementation of Graph for Graph references

The need comes from the fact that `AncestorsIterator` and many
Graph-related algorithms take ownership of the `Graph` they work with.
This, in turn is due to them needing to accept the `Index` instances
that are provided by the Python layers (that neither rhg nor `RHGitaly`
use, of course): the fact that nowadays the Python layer holds an object
that is itself implemented in Rust does not change the core problem that
they cannot be tracked by the borrow checker.

Even though it looks like cloning `Changelog` would be cheap, it seems
hard to guarantee that on the long run. The object is already too rich
for us to be comfortable with it, when using references is the most
natural and guaranteed way of proceeding.

The added test seems a bit superfleous, but it will act as a reminder
that this feature is really useful until something in the Mercurial code
base actually uses it.

https://bz.mercurial-scm.org/522

In the merge below, the file "foo" has the same contents in both
parents, but if we look at the file-level history, we'll notice that
the version in p1 is an ancestor of the version in p2. This test makes
sure that we'll use the version from p2 in the manifest of the merge
revision.

  $ hg init repo
  $ cd repo

  $ echo foo > foo
  $ hg ci -qAm 'add foo'

  $ echo bar >> foo
  $ hg ci -m 'change foo'

  $ hg backout -r tip -m 'backout changed foo'
  reverting foo
  changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ touch bar
  $ hg ci -qAm 'add bar'

  $ hg merge --debug
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
   foo: remote is newer -> g
  getting foo
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg debugstate | grep foo
  m   0         -2 unset               foo

  $ hg st -A foo
  M foo

  $ hg ci -m 'merge'

  $ hg manifest --debug | grep foo
  c6fc755d7e68f49f880599da29f15add41f42f5a 644   foo

  $ hg debugindex foo
     rev linkrev       nodeid    p1-nodeid    p2-nodeid
       0       0 2ed2a3912a0b 000000000000 000000000000
       1       1 6f4310b00b9a 2ed2a3912a0b 000000000000
       2       2 c6fc755d7e68 6f4310b00b9a 000000000000