tests/test-merge-closedheads.t

ui: refactor `readconfig()` into a form that can consume resources

The old form can't completely go away, because files outside of packages still
need to be read.  The name passed in here is a tuple of `package name, resource`
as needed by the resource API.

I like the idea of stating the config file is embedded in the executable by
listing is as `exe!package.resource`.  This would be consistent with how
`debuginstall` points to the executable for the python executable, lib, and
installed modules.  While in practice the filesystem path is available from the
backing ResourceReader when the resource is opened, it is a relative path on py2
and absolute on py3.  Further, while this would show in the `hg config` output
for each option if set as such here, it doesn't show in the `reading from...`
line when `--debug` is used.  The file isn't actually open where that prints, so
there's no way I see to get that info there.  So I opted for the simple prefix
to distinguish resources from files.

Differential Revision: https://phab.mercurial-scm.org/D7775

  $ hgcommit() {
  >    hg commit -u user "$@"
  > }

  $ hg init clhead
  $ cd clhead

  $ touch foo && hg add && hgcommit -m 'foo'
  adding foo
  $ touch bar && hg add && hgcommit -m 'bar'
  adding bar
  $ touch baz && hg add && hgcommit -m 'baz'
  adding baz

  $ echo "flub" > foo
  $ hgcommit -m "flub"
  $ echo "nub" > foo
  $ hgcommit -m "nub"

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "c1" > c1
  $ hg add c1
  $ hgcommit -m "c1"
  created new head
  $ echo "c2" > c1
  $ hgcommit -m "c2"

  $ hg up -C 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo "d1" > d1
  $ hg add d1
  $ hgcommit -m "d1"
  created new head
  $ echo "d2" > d1
  $ hgcommit -m "d2"
  $ hg tag -l good

fail with three heads
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  abort: branch 'default' has 3 heads - please merge with an explicit rev
  (run 'hg heads .' to see heads, specify rev with -r)
  [255]

close one of the heads
  $ hg up -C 6
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hgcommit -m 'close this head' --close-branch

succeed with two open heads
  $ hg up -C good
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hgcommit -m 'merged heads'

hg update -C 8
  $ hg update -C 8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

hg branch some-branch
  $ hg branch some-branch
  marked working directory as branch some-branch
  (branches are permanent and global, did you want a bookmark?)
hg commit
  $ hgcommit -m 'started some-branch'
hg commit --close-branch
  $ hgcommit --close-branch -m 'closed some-branch'

hg update default
  $ hg update default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
hg merge some-branch
  $ hg merge some-branch
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
hg commit (no reopening of some-branch)
  $ hgcommit -m 'merge with closed branch'

  $ cd ..