view tests/test-status-color.t @ 39496:2f9f7889549b

snapshot: introduce an intermediate `_refinedgroups` generator

This method will be used to improve the search for a good snapshot base. To
keep things simpler, we introduce the necessary function before doing any
delta base logic change. The next handful of commits will focus on refactoring
the code to let that new logic land as clearly as possible.

# General Idea

Right now, the search for a good delta base stop whenever we found a good one.
However, when using sparse-revlog, we should probably try a bit harder.

We do significant effort to increase delta re-use by jumping on "unrelated"
delta chains that provide better results. Moving to another chain for a better
result is good, but we have no guarantee we jump at a reasonable point in that
new chain. When we consider over the chains related to the parents, we start
from the higher-level snapshots. This is a way to consider the snapshot closer
to the current revision that has the best chance to produce a small delta. We
do benefit from this walk order when jumping to a better "unrelated" stack.

To counter-balance this, we'll introduce a way to "refine" the result. After a
good delta have been found, we'll keep searching for a better delta, using the
current best one as a starting point.

# Target Setup

The `finddeltainfo` method is responsible for the general search for a good
delta. It requests candidates base from `_candidategroups` and decides which
one are usable.

The `_candidategroups` generator act as a top-level filter, it does not care
about how we pick candidates, it just does basic filtering, excluding
revisions that have been tested already or that are an obvious misfit.

The `_rawgroups` generator is the one with the actual ancestors walking logic,
It does not care about what would do a good delta and what was already tested,
it just issues the initial candidates.

We introduce a new `_refinedgroup` function to bridge the gap between
`_candidategroups` and `_rawgroups`. It delegates the initial iteration logic
and then performing relevant refining of the valid base once found. (This
logic is yet to be added to function)

All these logics are fairly independent and easier to understand when standing
alone, not mixed with each other. It also makes it easy to test and try
different approaches for one of those four layers without affecting the other
ones.

# Technical details

To communicate `finddeltainfo` choice of "current best delta base" to the
`_refinegroup` logic, we plan to use python co-routine feature. The
`_candidategroups` and `_refinegroup` generators will become co-routine. This
will allow `_refinegroup` to detect when a good delta have been found and
triggers various refining steps.

For now, `_candidategroups` will just pass the value down the stack.

After poking at various option, the co-routine appears the best to keep each
layers focus on its duty, without the need to spread implementation details
across layers.

  $ 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'
  \x1b[0;32madding .hgignore\x1b[0m (esc)
  \x1b[0;32madding deleted\x1b[0m (esc)
  \x1b[0;32madding modified\x1b[0m (esc)
  \x1b[0;32madding removed\x1b[0m (esc)
  $ 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'
  \x1b[0;32madding .hgignore\x1b[0m (esc)
  \x1b[0;32madding deleted\x1b[0m (esc)
  \x1b[0;32madding modified\x1b[0m (esc)
  \x1b[0;32madding removed\x1b[0m (esc)
  $ 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'
  (use 'hg help' for a list of commands)
  [255]

color coding of error message without curses

  $ echo 'raise ImportError' > curses.py
  $ PYTHONPATH=`pwd`:$PYTHONPATH hg unknowncommand > /dev/null
  hg: unknown command 'unknowncommand'
  (use 'hg help' for a list of commands)
  [255]

  $ cd ..