tests/test-issue522.t

manifest: repurpose flagsdiff() into (node-and-flag)diff()

The manifestdict class already has a method for diff flags between two
manifests (presumably because there is no full access to the private
_flags field). The only caller is merge.manifestmerge(), which also
wants a diff of files between the same manifests. Let's combine the
code for diffing files and flags into a single method on
manifestdict. This puts all the manifest diffing in one place and will
allow for further simplification. It might also be useful for it to be
encapsulated in manifestdict if we later decide to to shard
manifests. The docstring is intentionally unclear about missing
entries for now.

http://mercurial.selenic.com/bts/issue522

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

  $ 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
    searching for copies back to rev 1
    unmatched files in local:
     bar
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
   foo: remote is newer -> g
  getting foo
  updating: foo 1/1 files (100.00%)
  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    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       5  .....       0 2ed2a3912a0b 000000000000 000000000000 (re)
       1         5       9  .....       1 6f4310b00b9a 2ed2a3912a0b 000000000000 (re)
       2        14       5  .....       2 c6fc755d7e68 6f4310b00b9a 000000000000 (re)