tests/test-double-merge.t

interfaces: convert the zope `Attribute` attrs to regular fields

At this point, we should have a useful protocol class.

The file syntax requires the type to be supplied for any fields that are
declared, but we'll leave the complex ones partially unspecified for now, for
simplicity.  (Also, the things documented as `Callable` are really as future
type annotating worked showed- roll with it for now, but they're marked as TODO
for fixing later.)  All of the fields and all of the attrs will need type
annotations, or the type rules say they are considered to be `Any`.  That can be
done in a separate pass, possibly applying the `dirstate.pyi` file generated
from the concrete class.

The first cut of this turned the `interfaceutil.Attribute` fields into plain
fields, and thus the types on them.  PyCharm flagged a few things as having
incompatible signatures when the concrete dirstate class subclassed this, when
the concrete class has them declared as `@property`.  So they've been changed to
`@property` here in those cases.  The remaining fields that are decorated in the
concrete class have comments noting the differences.  We'll see if they need to
be changed going forward, but leave them for now.  We'll be in trouble if the
`@util.propertycache` is needed, because we can't import that module here at
runtime, due to circular imports.

  $ hg init repo
  $ cd repo

  $ echo line 1 > foo
  $ hg ci -qAm 'add foo'

copy foo to bar and change both files
  $ hg cp foo bar
  $ echo line 2-1 >> foo
  $ echo line 2-2 >> bar
  $ hg ci -m 'cp foo bar; change both'

in another branch, change foo in a way that doesn't conflict with
the other changes
  $ hg up -qC 0
  $ echo line 0 > foo
  $ hg cat foo >> foo
  $ hg ci -m 'change foo'
  created new head

we get conflicts that shouldn't be there
  $ hg merge -P
  changeset:   1:484bf6903104
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     cp foo bar; change both
  
  $ hg merge --debug
    unmatched files in other:
     bar
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'foo' -> dst: 'bar' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104
  starting 4 threads for background file closing (?)
   preserving foo for resolve of bar
   preserving foo for resolve of foo
   bar: remote copied from foo -> m
  picked tool ':merge' for bar (binary False symlink False changedelete False)
  merging foo and bar to bar
  my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc
   premerge successful
   foo: versions differ -> m
  picked tool ':merge' for foo (binary False symlink False changedelete False)
  merging foo
  my foo@6a0df1dad128+ other foo@484bf6903104 ancestor foo@e6dc8efe11cc
   premerge successful
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

contents of foo
  $ cat foo
  line 0
  line 1
  line 2-1

contents of bar
  $ cat bar
  line 0
  line 1
  line 2-2

  $ cd ..