tests/test-diffstat.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.

  $ hg init repo
  $ cd repo
  $ i=0; while [ "$i" -lt 213 ]; do echo a >> a; i=`expr $i + 1`; done
  $ hg add a
  $ cp a b
  $ hg add b

Wide diffstat:

  $ hg diff --stat
   a |  213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   b |  213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   2 files changed, 426 insertions(+), 0 deletions(-)

diffstat width:

  $ COLUMNS=24 hg diff --config ui.interactive=true --stat
   a |  213 ++++++++++++++
   b |  213 ++++++++++++++
   2 files changed, 426 insertions(+), 0 deletions(-)

  $ hg ci -m adda

  $ cat >> a <<EOF
  > a
  > a
  > a
  > EOF

Narrow diffstat:

  $ hg diff --stat
   a |  3 +++
   1 files changed, 3 insertions(+), 0 deletions(-)

  $ hg ci -m appenda

  >>> open("c", "wb").write("\0")
  $ touch d
  $ hg add c d

Binary diffstat:

  $ hg diff --stat
   c |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

Binary git diffstat:

  $ hg diff --stat --git
   c |  Bin 
   d |    0 
   2 files changed, 0 insertions(+), 0 deletions(-)

  $ hg ci -m createb

  >>> open("file with spaces", "wb").write("\0")
  $ hg add "file with spaces"

Filename with spaces diffstat:

  $ hg diff --stat
   file with spaces |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

Filename with spaces git diffstat:

  $ hg diff --stat --git
   file with spaces |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

diffstat within directories:

  $ hg rm -f 'file with spaces'

  $ mkdir dir1 dir2
  $ echo new1 > dir1/new
  $ echo new2 > dir2/new
  $ hg add dir1/new dir2/new
  $ hg diff --stat
   dir1/new |  1 +
   dir2/new |  1 +
   2 files changed, 2 insertions(+), 0 deletions(-)

  $ hg diff --stat --root dir1
   new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ hg diff --stat --root dir1 dir2
  warning: dir2 not inside relative root dir1

  $ hg diff --stat --root dir1 -I dir1/old

  $ cd dir1
  $ hg diff --stat .
   dir1/new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)
  $ hg diff --stat --root .
   new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ hg diff --stat --root ../dir1 ../dir2
  warning: ../dir2 not inside relative root . (glob)

  $ hg diff --stat --root . -I old

  $ cd ..