tests/test-status-color.t

bundle2: increase payload part chunk size to 32kb

Bundle2 payload parts are framed chunks. Esentially, we obtain
data in equal size chunks of size `preferedchunksize` and emit those
to a generator. That generator is fed into a compressor (which can
be the no-op compressor, which just re-emits the generator). And
the output from the compressor likely goes to a file descriptor
or socket.

What this means is that small chunk sizes create more Python objects
and Python function calls than larger chunk sizes. And as we know,
Python object and function call overhead in performance sensitive
code matters (at least with CPython).

This commit increases the bundle2 part payload chunk size from 4k
to 32k. Practically speaking, this means that the chunks we feed
into a compressor (implemented in C code) or feed directly into a
file handle or socket write() are larger. It's possible the chunks
might be larger than what the receiver can handle in one logical
operation. But at that point, we're in C code, which is much more
efficient at dealing with splitting up the chunk and making multiple
function calls than Python is.

A downside to larger chunks is that the receiver has to wait for that
much data to arrive (either raw or from a decompressor) before it
can process the chunk. But 32kb still feels like a small buffer to
have to wait for. And in many cases, the client will convert from
8 read(4096) to 1 read(32768). That's happening in Python land. So
we cut down on the number of Python objects and function calls,
making the client faster as well. I don't think there are any
significant concerns to increasing the payload chunk size to 32kb.

The impact of this change on performance significant. Using `curl`
to obtain a stream clone bundle2 payload from a server on localhost
serving the mozilla-unified repository:

before: 20.78 user; 7.71 system;  80.5 MB/s
after:  13.90 user; 3.51 system; 132 MB/s
legacy:  9.72 user; 8.16 system; 132 MB/s

bundle2 stream clone generation is still more resource intensive than
legacy stream clone (that's likely because of the use of a
util.chunkbuffer). But the throughput is the same. We might
be in territory we're this is effectively a benchmark of the
networking stack or Python's syscall throughput.

From the client perspective, `hg clone -U --stream`:

before: 33.50 user; 7.95 system; 53.3 MB/s
after:  22.82 user; 7.33 system; 72.7 MB/s
legacy: 29.96 user; 7.94 system; 58.0 MB/s

And for `hg clone --stream` with a working directory update of
~230k files:

after:  119.55 user; 26.47 system; 0:57.08 wall
legacy: 126.98 user; 26.94 system; 1:05.56 wall

So, it appears that bundle2's stream clone is now definitively faster
than legacy stream clone!

Differential Revision: https://phab.mercurial-scm.org/D1932

  $ cat <<EOF >> $HGRCPATH
  > [ui]
  > color = always
  > [color]
  > mode = ansi
  > EOF
Terminfo codes compatibility fix
  $ echo "color.none=0" >> $HGRCPATH

  $ hg init repo1
  $ cd repo1
  $ mkdir a b a/1 b/1 b/2
  $ touch in_root a/in_a b/in_b a/1/in_a_1 b/1/in_b_1 b/2/in_b_2

hg status in repo root:

  $ hg status
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)

  $ hg status --color=debug
  [status.unknown|? ][status.unknown|a/1/in_a_1]
  [status.unknown|? ][status.unknown|a/in_a]
  [status.unknown|? ][status.unknown|b/1/in_b_1]
  [status.unknown|? ][status.unknown|b/2/in_b_2]
  [status.unknown|? ][status.unknown|b/in_b]
  [status.unknown|? ][status.unknown|in_root]
HGPLAIN disables color
  $ HGPLAIN=1 hg status --color=debug
  ? a/1/in_a_1 (glob)
  ? a/in_a (glob)
  ? b/1/in_b_1 (glob)
  ? b/2/in_b_2 (glob)
  ? b/in_b (glob)
  ? in_root
HGPLAINEXCEPT=color does not disable color
  $ HGPLAINEXCEPT=color hg status --color=debug
  [status.unknown|? ][status.unknown|a/1/in_a_1] (glob)
  [status.unknown|? ][status.unknown|a/in_a] (glob)
  [status.unknown|? ][status.unknown|b/1/in_b_1] (glob)
  [status.unknown|? ][status.unknown|b/2/in_b_2] (glob)
  [status.unknown|? ][status.unknown|b/in_b] (glob)
  [status.unknown|? ][status.unknown|in_root]

hg status with template
  $ hg status -T "{label('red', path)}\n" --color=debug
  [red|a/1/in_a_1]
  [red|a/in_a]
  [red|b/1/in_b_1]
  [red|b/2/in_b_2]
  [red|b/in_b]
  [red|in_root]

hg status . in repo root:

  $ hg status .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)

  $ hg status --cwd a
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)
  $ hg status --cwd a .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_a\x1b[0m (esc)
  $ hg status --cwd a ..
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../b/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../b/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../b/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../in_root\x1b[0m (esc)

  $ hg status --cwd b
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)
  $ hg status --cwd b .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b\x1b[0m (esc)
  $ hg status --cwd b ..
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../a/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../a/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../in_root\x1b[0m (esc)

  $ hg status --cwd a/1
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)
  $ hg status --cwd a/1 .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_a_1\x1b[0m (esc)
  $ hg status --cwd a/1 ..
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../in_a\x1b[0m (esc)

  $ hg status --cwd b/1
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)
  $ hg status --cwd b/1 .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b_1\x1b[0m (esc)
  $ hg status --cwd b/1 ..
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../in_b\x1b[0m (esc)

  $ hg status --cwd b/2
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/1/in_a_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4ma/in_a\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/2/in_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mb/in_b\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_root\x1b[0m (esc)
  $ hg status --cwd b/2 .
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b_2\x1b[0m (esc)
  $ hg status --cwd b/2 ..
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../1/in_b_1\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4min_b_2\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4m../in_b\x1b[0m (esc)

Make sure --color=never works
  $ hg status --color=never
  ? a/1/in_a_1
  ? a/in_a
  ? b/1/in_b_1
  ? b/2/in_b_2
  ? b/in_b
  ? in_root

Make sure ui.formatted=False works
  $ hg status --color=auto --config ui.formatted=False
  ? a/1/in_a_1
  ? a/in_a
  ? b/1/in_b_1
  ? b/2/in_b_2
  ? b/in_b
  ? in_root

  $ cd ..

  $ hg init repo2
  $ cd repo2
  $ touch modified removed deleted ignored
  $ echo "^ignored$" > .hgignore
  $ hg ci -A -m 'initial checkin'
  adding .hgignore
  adding deleted
  adding modified
  adding removed
  $ hg log --color=debug
  [log.changeset changeset.draft|changeset:   0:389aef86a55e]
  [log.tag|tag:         tip]
  [log.user|user:        test]
  [log.date|date:        Thu Jan 01 00:00:00 1970 +0000]
  [log.summary|summary:     initial checkin]
  
  $ hg log -Tcompact --color=debug
  [log.changeset changeset.draft|0][tip]   [log.node|389aef86a55e]   [log.date|1970-01-01 00:00 +0000]   [log.user|test]
    [ui.note log.description|initial checkin]
  
Labels on empty strings should not be displayed, labels on custom
templates should be.

  $ hg log --color=debug -T '{label("my.label",author)}\n{label("skipped.label","")}'
  [my.label|test]
  $ touch modified added unknown ignored
  $ hg add added
  $ hg remove removed
  $ rm deleted

hg status:

  $ hg status
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1madded\x1b[0m (esc)
  \x1b[0;31;1mR \x1b[0m\x1b[0;31;1mremoved\x1b[0m (esc)
  \x1b[0;36;1;4m! \x1b[0m\x1b[0;36;1;4mdeleted\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4munknown\x1b[0m (esc)

hg status modified added removed deleted unknown never-existed ignored:

  $ hg status modified added removed deleted unknown never-existed ignored
  never-existed: * (glob)
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1madded\x1b[0m (esc)
  \x1b[0;31;1mR \x1b[0m\x1b[0;31;1mremoved\x1b[0m (esc)
  \x1b[0;36;1;4m! \x1b[0m\x1b[0;36;1;4mdeleted\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4munknown\x1b[0m (esc)

  $ hg copy modified copied

hg status -C:

  $ hg status -C
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1madded\x1b[0m (esc)
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1mcopied\x1b[0m (esc)
  \x1b[0;0m  modified\x1b[0m (esc)
  \x1b[0;31;1mR \x1b[0m\x1b[0;31;1mremoved\x1b[0m (esc)
  \x1b[0;36;1;4m! \x1b[0m\x1b[0;36;1;4mdeleted\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4munknown\x1b[0m (esc)

hg status -A:

  $ hg status -A
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1madded\x1b[0m (esc)
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1mcopied\x1b[0m (esc)
  \x1b[0;0m  modified\x1b[0m (esc)
  \x1b[0;31;1mR \x1b[0m\x1b[0;31;1mremoved\x1b[0m (esc)
  \x1b[0;36;1;4m! \x1b[0m\x1b[0;36;1;4mdeleted\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4munknown\x1b[0m (esc)
  \x1b[0;30;1mI \x1b[0m\x1b[0;30;1mignored\x1b[0m (esc)
  \x1b[0;0mC \x1b[0m\x1b[0;0m.hgignore\x1b[0m (esc)
  \x1b[0;0mC \x1b[0m\x1b[0;0mmodified\x1b[0m (esc)


hg status -A (with terminfo color):

#if tic

  $ mkdir "$TESTTMP/terminfo"
  $ TERMINFO="$TESTTMP/terminfo" tic "$TESTDIR/hgterm.ti"
  $ TERM=hgterm TERMINFO="$TESTTMP/terminfo" hg status --config color.mode=terminfo -A
  \x1b[30m\x1b[32m\x1b[1mA \x1b[30m\x1b[30m\x1b[32m\x1b[1madded\x1b[30m (esc)
  \x1b[30m\x1b[32m\x1b[1mA \x1b[30m\x1b[30m\x1b[32m\x1b[1mcopied\x1b[30m (esc)
  \x1b[30m\x1b[30m  modified\x1b[30m (esc)
  \x1b[30m\x1b[31m\x1b[1mR \x1b[30m\x1b[30m\x1b[31m\x1b[1mremoved\x1b[30m (esc)
  \x1b[30m\x1b[36m\x1b[1m\x1b[4m! \x1b[30m\x1b[30m\x1b[36m\x1b[1m\x1b[4mdeleted\x1b[30m (esc)
  \x1b[30m\x1b[35m\x1b[1m\x1b[4m? \x1b[30m\x1b[30m\x1b[35m\x1b[1m\x1b[4munknown\x1b[30m (esc)
  \x1b[30m\x1b[30m\x1b[1mI \x1b[30m\x1b[30m\x1b[30m\x1b[1mignored\x1b[30m (esc)
  \x1b[30m\x1b[30mC \x1b[30m\x1b[30m\x1b[30m.hgignore\x1b[30m (esc)
  \x1b[30m\x1b[30mC \x1b[30m\x1b[30m\x1b[30mmodified\x1b[30m (esc)

The user can define effects with raw terminfo codes:

  $ cat <<EOF >> $HGRCPATH
  > # Completely bogus code for dim
  > terminfo.dim = \E[88m
  > # We can override what's in the terminfo database, too
  > terminfo.bold = \E[2m
  > EOF
  $ TERM=hgterm TERMINFO="$TESTTMP/terminfo" hg status --config color.mode=terminfo --config color.status.clean=dim -A
  \x1b[30m\x1b[32m\x1b[2mA \x1b[30m\x1b[30m\x1b[32m\x1b[2madded\x1b[30m (esc)
  \x1b[30m\x1b[32m\x1b[2mA \x1b[30m\x1b[30m\x1b[32m\x1b[2mcopied\x1b[30m (esc)
  \x1b[30m\x1b[30m  modified\x1b[30m (esc)
  \x1b[30m\x1b[31m\x1b[2mR \x1b[30m\x1b[30m\x1b[31m\x1b[2mremoved\x1b[30m (esc)
  \x1b[30m\x1b[36m\x1b[2m\x1b[4m! \x1b[30m\x1b[30m\x1b[36m\x1b[2m\x1b[4mdeleted\x1b[30m (esc)
  \x1b[30m\x1b[35m\x1b[2m\x1b[4m? \x1b[30m\x1b[30m\x1b[35m\x1b[2m\x1b[4munknown\x1b[30m (esc)
  \x1b[30m\x1b[30m\x1b[2mI \x1b[30m\x1b[30m\x1b[30m\x1b[2mignored\x1b[30m (esc)
  \x1b[30m\x1b[88mC \x1b[30m\x1b[30m\x1b[88m.hgignore\x1b[30m (esc)
  \x1b[30m\x1b[88mC \x1b[30m\x1b[30m\x1b[88mmodified\x1b[30m (esc)

#endif


  $ echo "^ignoreddir$" > .hgignore
  $ mkdir ignoreddir
  $ touch ignoreddir/file

hg status ignoreddir/file:

  $ hg status ignoreddir/file

hg status -i ignoreddir/file:

  $ hg status -i ignoreddir/file
  \x1b[0;30;1mI \x1b[0m\x1b[0;30;1mignoreddir/file\x1b[0m (esc)
  $ cd ..

check 'status -q' and some combinations

  $ hg init repo3
  $ cd repo3
  $ touch modified removed deleted ignored
  $ echo "^ignored$" > .hgignore
  $ hg commit -A -m 'initial checkin'
  adding .hgignore
  adding deleted
  adding modified
  adding removed
  $ touch added unknown ignored
  $ hg add added
  $ echo "test" >> modified
  $ hg remove removed
  $ rm deleted
  $ hg copy modified copied

test unknown color

  $ hg --config color.status.modified=periwinkle status
  ignoring unknown color/effect 'periwinkle' (configured in color.status.modified)
  ignoring unknown color/effect 'periwinkle' (configured in color.status.modified)
  ignoring unknown color/effect 'periwinkle' (configured in color.status.modified)
  M modified
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1madded\x1b[0m (esc)
  \x1b[0;32;1mA \x1b[0m\x1b[0;32;1mcopied\x1b[0m (esc)
  \x1b[0;31;1mR \x1b[0m\x1b[0;31;1mremoved\x1b[0m (esc)
  \x1b[0;36;1;4m! \x1b[0m\x1b[0;36;1;4mdeleted\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4munknown\x1b[0m (esc)

Run status with 2 different flags.
Check if result is the same or different.
If result is not as expected, raise error

  $ assert() {
  >     hg status $1 > ../a
  >     hg status $2 > ../b
  >     if diff ../a ../b > /dev/null; then
  >         out=0
  >     else
  >         out=1
  >     fi
  >     if [ $3 -eq 0 ]; then
  >         df="same"
  >     else
  >         df="different"
  >     fi
  >     if [ $out -ne $3 ]; then
  >         echo "Error on $1 and $2, should be $df."
  >     fi
  > }

assert flag1 flag2 [0-same | 1-different]

  $ assert "-q" "-mard"      0
  $ assert "-A" "-marduicC"  0
  $ assert "-qA" "-mardcC"   0
  $ assert "-qAui" "-A"      0
  $ assert "-qAu" "-marducC" 0
  $ assert "-qAi" "-mardicC" 0
  $ assert "-qu" "-u"        0
  $ assert "-q" "-u"         1
  $ assert "-m" "-a"         1
  $ assert "-r" "-d"         1
  $ cd ..

test 'resolve -l'

  $ hg init repo4
  $ cd repo4
  $ echo "file a" > a
  $ echo "file b" > b
  $ hg add a b
  $ hg commit -m "initial"
  $ echo "file a change 1" > a
  $ echo "file b change 1" > b
  $ hg commit -m "head 1"
  $ hg update 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo "file a change 2" > a
  $ echo "file b change 2" > b
  $ hg commit -m "head 2"
  created new head
  $ hg merge
  merging a
  merging b
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 2 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg resolve -m b

hg resolve with one unresolved, one resolved:

  $ hg resolve -l
  \x1b[0;31;1mU \x1b[0m\x1b[0;31;1ma\x1b[0m (esc)
  \x1b[0;32;1mR \x1b[0m\x1b[0;32;1mb\x1b[0m (esc)

color coding of error message with current availability of curses

  $ hg unknowncommand > /dev/null
  hg: unknown command 'unknowncommand'
  [255]

color coding of error message without curses

  $ echo 'raise ImportError' > curses.py
  $ PYTHONPATH=`pwd`:$PYTHONPATH hg unknowncommand > /dev/null
  hg: unknown command 'unknowncommand'
  [255]

  $ cd ..