view tests/test-status-color.t @ 40056:324b4b10351e

revlog: rewrite censoring logic

I was able to corrupt a revlog relatively easily with the existing
censoring code. The underlying problem is that the existing code
doesn't fully take delta chains into account. When copying revisions
that occur after the censored revision, the delta base can refer
to a censored revision. Then at read time, things blow up due to the
revision data not being a compressed delta.

This commit rewrites the revlog censoring code to take a higher-level
approach. We now create a new revlog instance pointing at temp files.
We iterate through each revision in the source revlog and insert
those revisions into the new revlog, replacing the censored revision's
data along the way.

The new implementation isn't as efficient as the old one. This is
because it will fully engage delta computation on insertion. But I
don't think it matters.

The new implementation is a bit hacky because it attempts to reload
the revlog instance with a new revlog index/data file. This is fragile.
But this is needed because the index (which could be backed by C) would
have a cached copy of the old, possibly changed data and that could
lead to problems accessing index or revision data later.

One benefit of the new approach is that we integrate with the
transaction. The old revlog is backed up and if the transaction is
rolled back, the original revlog is restored.

As part of this, we had to teach the transaction about the store
vfs. I'm not super keen about this. But this was the easiest way
to hook things up to the transaction. We /could/ just ignore the
transaction like we were doing before. But any file mutation should
be governed by transaction semantics, including undo during rollback.

Differential Revision: https://phab.mercurial-scm.org/D4869

  $ 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 ..