tests/test-empty-file.t

windows: use normalized path as path to subrepo

path to subrepo is used to identify or check location of subrepo.

it should be normalized (in "/" delimiter form), because it is also
used with narrowmatcher which uses only normalized path even on
Windows environment.

this patch applies "util.pconvert()" on path to subrepo (called
"subpath") to normalize it.

for this patch, referers of below were checked.

  - subrepo.state()
  - subrepo.itersubrepos()
  - subrepo.subrepo()
  - context.sub()
  - context.substate()

typical usecase is:

    for subpath in ctx.substate:
        sub = ctx.sub(subpath)
        ... ctx.substate[subpath] ....

in this case, normalization has no side effect, because keys given
from substate are used as key itself.

other cases shown below also seem to require subpath to be normalized.

    - path components are joined by "/", in "commands.forget()":

        for subpath in ctx.substate:
            subforget[subpath + '/' + fsub] = (fsub, sub)

    - normalized "file" is used to check below condition, in
      "commands.revert()", "localrepository.commit()", and
      "localrepository._checknested()"

        file in ctx.substate

    - substate.keys() is passed to dirstate.walk()/status() which use
      only normalized pathes

  $ hg init a
  $ cd a
  $ touch empty1
  $ hg add empty1
  $ hg commit -m 'add empty1'

  $ touch empty2
  $ hg add empty2
  $ hg commit -m 'add empty2'

  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ touch empty3
  $ hg add empty3
  $ hg commit -m 'add empty3'
  created new head

  $ hg heads
  changeset:   2:a1cb177e0d44
  tag:         tip
  parent:      0:1e1d9c4e5b64
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty3
  
  changeset:   1:097d2b0e17f6
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty2
  

  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Before changeset 05257fd28591, we didn't notice the
empty file that came from rev 1:

  $ hg status
  M empty2
  $ hg commit -m merge
  $ hg manifest --debug tip
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty1
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty2
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty3