tests/test-record.t

dirstate.walk: don't keep track of normalized files in parallel

Rev 2bb13f2b778c changed the semantics of the work list to store (normalized,
non-normalized) pairs. All the tuple creation and destruction hurts perf: on a
large repo on OS X, 'hg status' went from 3.62 seconds to 3.78.

It also is unnecessary in most cases:
- it is clearly unnecessary on case-sensitive filesystems.
- it is also unnecessary when filenames have been read off of disk rather than
  being supplied by the user.

The only case where the non-normalized case is required at all is when the file
is unknown.

To eliminate most of the perf cost, keep trace of whether the directory needs
to be normalized at all with a boolean called 'alreadynormed'. Pay the cost of
directory normalization only when necessary.

For the above large repo, 'hg status' goes to 3.63 seconds.

Set up a repo

  $ cat <<EOF >> $HGRCPATH
  > [ui]
  > interactive = true
  > [extensions]
  > record =
  > EOF

  $ hg init a
  $ cd a

Record help

  $ hg record -h
  hg record [OPTION]... [FILE]...
  
  interactively select changes to commit
  
      If a list of files is omitted, all changes reported by "hg status" will be
      candidates for recording.
  
      See "hg help dates" for a list of formats valid for -d/--date.
  
      You will be prompted for whether to record changes to each modified file,
      and for files with multiple changes, for each change to use. For each
      query, the following responses are possible:
  
        y - record this change
        n - skip this change
        e - edit this change manually
  
        s - skip remaining changes to this file
        f - record remaining changes to this file
  
        d - done, skip remaining changes and files
        a - record all changes to all remaining files
        q - quit, recording no changes
  
        ? - display help
  
      This command is not available when committing a merge.
  
  options ([+] can be repeated):
  
   -A --addremove           mark new/missing files as added/removed before
                            committing
      --close-branch        mark a branch as closed, hiding it from the branch
                            list
      --amend               amend the parent of the working directory
   -s --secret              use the secret phase for committing
   -e --edit                invoke editor on commit messages
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
   -d --date DATE           record the specified date as commit date
   -u --user USER           record the specified user as committer
   -S --subrepos            recurse into subrepositories
   -w --ignore-all-space    ignore white space when comparing lines
   -b --ignore-space-change ignore changes in the amount of white space
   -B --ignore-blank-lines  ignore changes whose lines are all blank
  
  (some details hidden, use --verbose to show complete help)

Select no files

  $ touch empty-rw
  $ hg add empty-rw

  $ hg record empty-rw<<EOF
  > n
  > EOF
  diff --git a/empty-rw b/empty-rw
  new file mode 100644
  examine changes to 'empty-rw'? [Ynesfdaq?] n
  
  no changes to record

  $ hg tip -p
  changeset:   -1:000000000000
  tag:         tip
  user:        
  date:        Thu Jan 01 00:00:00 1970 +0000