tests/test-double-merge.t

repo: rephrase the "missing requirement" error message

Unknown requirements will now be reported as:
  abort: repository requires features unknown to this Mercurial: largefiles!
  (see http://mercurial.selenic.com/wiki/MissingRequirement for more information)

Some features of this phrasing:
* avoid double ':' in abort message
* make it more clear who requires and knows what
* don't quote the requirement names - it is not something the user entered or
  need the exact spelling of ... and it is "identifiers" that are unambiguous
  anyway
* remove double hint by removing "(upgrade Mercurial)" comment
* don't mention upgrading Mercurial without mentioning enabling the feature -
  instead, just refer to wiki page for both
* don't just talk about "details", talk about "more information"

  $ 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
    searching for copies back to rev 1
    unmatched files in other:
     bar
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'foo' -> dst: 'bar' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104
   foo: remote copied to bar -> m
    preserving foo for resolve of bar
   foo: versions differ -> m
    preserving foo for resolve of foo
  updating: foo 1/2 files (50.00%)
  picked tool 'internal:merge' for bar (binary False symlink False)
  merging foo and bar to bar
  my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc
   premerge successful
  updating: foo 2/2 files (100.00%)
  picked tool 'internal:merge' for foo (binary False symlink 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 ..