color: don't infer vt status from TERM on Windows

Previously, it was assumed that Windows environments with
"xterm" in the TERM environment variable meant that either
"virtual terminal mode" was already enabled, or that
we are running in an environment that didn't need a "virtual
terminal mode" (such as mintty, that interprets ANSI sequences
itself).

However, modern Cygwin and MSYS2 set TERM=xterm when using the
Command Prompt as the terminal, which needs "virtual terminal
mode" to be manually enabled. However, due to (issue6640),
the vtmode wasn't being enabled.

This patch ensures that we always try to enable vtmode on
Windows regardless of the state of TERM, so that:
* ANSI-based colors work in modern Cygwin/MSYS2 (with Command
  Prompt), and
* The vtmode is unnecessarily set when running in a different
  terminal such as mintty, but it is simply redundant and doesn't
  appear to have ill effects.

Differential Revision: https://phab.mercurial-scm.org/D12158

mercurial/color.py

@@ -1,577 +1,568 b''
 # utility for color output for Mercurial commands
 #
 # Copyright (C) 2007 Kevin Christen <[e-mail]> and other
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import re
 
 from .i18n import _
 from .pycompat import getattr
 
 from . import (
     encoding,
     pycompat,
 )
 
 from .utils import stringutil
 
 try:
     import curses
 
     # Mapping from effect name to terminfo attribute name (or raw code) or
     # color number.  This will also force-load the curses module.
     _baseterminfoparams = {
         b'none': (True, b'sgr0', b''),
         b'standout': (True, b'smso', b''),
         b'underline': (True, b'smul', b''),
         b'reverse': (True, b'rev', b''),
         b'inverse': (True, b'rev', b''),
         b'blink': (True, b'blink', b''),
         b'dim': (True, b'dim', b''),
         b'bold': (True, b'bold', b''),
         b'invisible': (True, b'invis', b''),
         b'italic': (True, b'sitm', b''),
         b'black': (False, curses.COLOR_BLACK, b''),
         b'red': (False, curses.COLOR_RED, b''),
         b'green': (False, curses.COLOR_GREEN, b''),
         b'yellow': (False, curses.COLOR_YELLOW, b''),
         b'blue': (False, curses.COLOR_BLUE, b''),
         b'magenta': (False, curses.COLOR_MAGENTA, b''),
         b'cyan': (False, curses.COLOR_CYAN, b''),
         b'white': (False, curses.COLOR_WHITE, b''),
     }
 except (ImportError, AttributeError):
     curses = None
     _baseterminfoparams = {}
 
 # start and stop parameters for effects
 _effects = {
     b'none': 0,
     b'black': 30,
     b'red': 31,
     b'green': 32,
     b'yellow': 33,
     b'blue': 34,
     b'magenta': 35,
     b'cyan': 36,
     b'white': 37,
     b'bold': 1,
     b'italic': 3,
     b'underline': 4,
     b'inverse': 7,
     b'dim': 2,
     b'black_background': 40,
     b'red_background': 41,
     b'green_background': 42,
     b'yellow_background': 43,
     b'blue_background': 44,
     b'purple_background': 45,
     b'cyan_background': 46,
     b'white_background': 47,
 }
 
 _defaultstyles = {
     b'grep.match': b'red bold',
     b'grep.linenumber': b'green',
     b'grep.rev': b'blue',
     b'grep.sep': b'cyan',
     b'grep.filename': b'magenta',
     b'grep.user': b'magenta',
     b'grep.date': b'magenta',
     b'grep.inserted': b'green bold',
     b'grep.deleted': b'red bold',
     b'bookmarks.active': b'green',
     b'branches.active': b'none',
     b'branches.closed': b'black bold',
     b'branches.current': b'green',
     b'branches.inactive': b'none',
     b'diff.changed': b'white',
     b'diff.deleted': b'red',
     b'diff.deleted.changed': b'red bold underline',
     b'diff.deleted.unchanged': b'red',
     b'diff.diffline': b'bold',
     b'diff.extended': b'cyan bold',
     b'diff.file_a': b'red bold',
     b'diff.file_b': b'green bold',
     b'diff.hunk': b'magenta',
     b'diff.inserted': b'green',
     b'diff.inserted.changed': b'green bold underline',
     b'diff.inserted.unchanged': b'green',
     b'diff.tab': b'',
     b'diff.trailingwhitespace': b'bold red_background',
     b'changeset.public': b'',
     b'changeset.draft': b'',
     b'changeset.secret': b'',
     b'diffstat.deleted': b'red',
     b'diffstat.inserted': b'green',
     b'formatvariant.name.mismatchconfig': b'red',
     b'formatvariant.name.mismatchdefault': b'yellow',
     b'formatvariant.name.uptodate': b'green',
     b'formatvariant.repo.mismatchconfig': b'red',
     b'formatvariant.repo.mismatchdefault': b'yellow',
     b'formatvariant.repo.uptodate': b'green',
     b'formatvariant.config.special': b'yellow',
     b'formatvariant.config.default': b'green',
     b'formatvariant.default': b'',
     b'histedit.remaining': b'red bold',
     b'ui.addremove.added': b'green',
     b'ui.addremove.removed': b'red',
     b'ui.error': b'red',
     b'ui.prompt': b'yellow',
     b'log.changeset': b'yellow',
     b'patchbomb.finalsummary': b'',
     b'patchbomb.from': b'magenta',
     b'patchbomb.to': b'cyan',
     b'patchbomb.subject': b'green',
     b'patchbomb.diffstats': b'',
     b'rebase.rebased': b'blue',
     b'rebase.remaining': b'red bold',
     b'resolve.resolved': b'green bold',
     b'resolve.unresolved': b'red bold',
     b'shelve.age': b'cyan',
     b'shelve.newest': b'green bold',
     b'shelve.name': b'blue bold',
     b'status.added': b'green bold',
     b'status.clean': b'none',
     b'status.copied': b'none',
     b'status.deleted': b'cyan bold underline',
     b'status.ignored': b'black bold',
     b'status.modified': b'blue bold',
     b'status.removed': b'red bold',
     b'status.unknown': b'magenta bold underline',
     b'tags.normal': b'green',
     b'tags.local': b'black bold',
     b'upgrade-repo.requirement.preserved': b'cyan',
     b'upgrade-repo.requirement.added': b'green',
     b'upgrade-repo.requirement.removed': b'red',
 }
 
 
 def loadcolortable(ui, extname, colortable):
     _defaultstyles.update(colortable)
 
 
 def _terminfosetup(ui, mode, formatted):
     '''Initialize terminfo data and the terminal if we're in terminfo mode.'''
 
     # If we failed to load curses, we go ahead and return.
     if curses is None:
         return
     # Otherwise, see what the config file says.
     if mode not in (b'auto', b'terminfo'):
         return
     ui._terminfoparams.update(_baseterminfoparams)
 
     for key, val in ui.configitems(b'color'):
         if key.startswith(b'color.'):
             newval = (False, int(val), b'')
             ui._terminfoparams[key[6:]] = newval
         elif key.startswith(b'terminfo.'):
             newval = (True, b'', val.replace(b'\\E', b'\x1b'))
             ui._terminfoparams[key[9:]] = newval
     try:
         curses.setupterm()
     except curses.error:
         ui._terminfoparams.clear()
         return
 
     for key, (b, e, c) in ui._terminfoparams.copy().items():
         if not b:
             continue
         if not c and not curses.tigetstr(pycompat.sysstr(e)):
             # Most terminals don't support dim, invis, etc, so don't be
             # noisy and use ui.debug().
             ui.debug(b"no terminfo entry for %s\n" % e)
             del ui._terminfoparams[key]
     if not curses.tigetstr('setaf') or not curses.tigetstr('setab'):
         # Only warn about missing terminfo entries if we explicitly asked for
         # terminfo mode and we're in a formatted terminal.
         if mode == b"terminfo" and formatted:
             ui.warn(
                 _(
                     b"no terminfo entry for setab/setaf: reverting to "
                     b"ECMA-48 color\n"
                 )
             )
         ui._terminfoparams.clear()
 
 
 def setup(ui):
     """configure color on a ui
 
     That function both set the colormode for the ui object and read
     the configuration looking for custom colors and effect definitions."""
     mode = _modesetup(ui)
     ui._colormode = mode
     if mode and mode != b'debug':
         configstyles(ui)
 
 
 def _modesetup(ui):
     if ui.plain(b'color'):
         return None
     config = ui.config(b'ui', b'color')
     if config == b'debug':
         return b'debug'
 
     auto = config == b'auto'
     always = False
     if not auto and stringutil.parsebool(config):
         # We want the config to behave like a boolean, "on" is actually auto,
         # but "always" value is treated as a special case to reduce confusion.
         if (
             ui.configsource(b'ui', b'color') == b'--color'
             or config == b'always'
         ):
             always = True
         else:
             auto = True
 
     if not always and not auto:
         return None
 
     formatted = always or (
         encoding.environ.get(b'TERM') != b'dumb' and ui.formatted()
     )
 
     mode = ui.config(b'color', b'mode')
 
     # If pager is active, color.pagermode overrides color.mode.
     if getattr(ui, 'pageractive', False):
         mode = ui.config(b'color', b'pagermode', mode)
 
     realmode = mode
     if pycompat.iswindows:
         from . import win32
 
-        term = encoding.environ.get(b'TERM')
-        # TERM won't be defined in a vanilla cmd.exe environment.
-
-        # UNIX-like environments on Windows such as Cygwin and MSYS will
-        # set TERM. They appear to make a best effort attempt at setting it
-        # to something appropriate. However, not all environments with TERM
-        # defined support ANSI.
-        ansienviron = term and b'xterm' in term
-
         if mode == b'auto':
             # Since "ansi" could result in terminal gibberish, we error on the
             # side of selecting "win32". However, if w32effects is not defined,
             # we almost certainly don't support "win32", so don't even try.
             # w32effects is not populated when stdout is redirected, so checking
             # it first avoids win32 calls in a state known to error out.
-            if ansienviron or not w32effects or win32.enablevtmode():
+            if not w32effects or win32.enablevtmode():
                 realmode = b'ansi'
             else:
                 realmode = b'win32'
         # An empty w32effects is a clue that stdout is redirected, and thus
         # cannot enable VT mode.
-        elif mode == b'ansi' and w32effects and not ansienviron:
+        elif mode == b'ansi' and w32effects:
             win32.enablevtmode()
     elif mode == b'auto':
         realmode = b'ansi'
 
     def modewarn():
         # only warn if color.mode was explicitly set and we're in
         # a formatted terminal
         if mode == realmode and formatted:
             ui.warn(_(b'warning: failed to set color mode to %s\n') % mode)
 
     if realmode == b'win32':
         ui._terminfoparams.clear()
         if not w32effects:
             modewarn()
             return None
     elif realmode == b'ansi':
         ui._terminfoparams.clear()
     elif realmode == b'terminfo':
         _terminfosetup(ui, mode, formatted)
         if not ui._terminfoparams:
             ## FIXME Shouldn't we return None in this case too?
             modewarn()
             realmode = b'ansi'
     else:
         return None
 
     if always or (auto and formatted):
         return realmode
     return None
 
 
 def configstyles(ui):
     ui._styles.update(_defaultstyles)
     for status, cfgeffects in ui.configitems(b'color'):
         if b'.' not in status or status.startswith((b'color.', b'terminfo.')):
             continue
         cfgeffects = ui.configlist(b'color', status)
         if cfgeffects:
             good = []
             for e in cfgeffects:
                 if valideffect(ui, e):
                     good.append(e)
                 else:
                     ui.warn(
                         _(
                             b"ignoring unknown color/effect %s "
                             b"(configured in color.%s)\n"
                         )
                         % (stringutil.pprint(e), status)
                     )
             ui._styles[status] = b' '.join(good)
 
 
 def _activeeffects(ui):
     '''Return the effects map for the color mode set on the ui.'''
     if ui._colormode == b'win32':
         return w32effects
     elif ui._colormode is not None:
         return _effects
     return {}
 
 
 def valideffect(ui, effect):
     """Determine if the effect is valid or not."""
     return (not ui._terminfoparams and effect in _activeeffects(ui)) or (
         effect in ui._terminfoparams or effect[:-11] in ui._terminfoparams
     )
 
 
 def _effect_str(ui, effect):
     '''Helper function for render_effects().'''
 
     bg = False
     if effect.endswith(b'_background'):
         bg = True
         effect = effect[:-11]
     try:
         attr, val, termcode = ui._terminfoparams[effect]
     except KeyError:
         return b''
     if attr:
         if termcode:
             return termcode
         else:
             return curses.tigetstr(pycompat.sysstr(val))
     elif bg:
         return curses.tparm(curses.tigetstr('setab'), val)
     else:
         return curses.tparm(curses.tigetstr('setaf'), val)
 
 
 def _mergeeffects(text, start, stop):
     """Insert start sequence at every occurrence of stop sequence
 
     >>> s = _mergeeffects(b'cyan', b'[C]', b'|')
     >>> s = _mergeeffects(s + b'yellow', b'[Y]', b'|')
     >>> s = _mergeeffects(b'ma' + s + b'genta', b'[M]', b'|')
     >>> s = _mergeeffects(b'red' + s, b'[R]', b'|')
     >>> s
     '[R]red[M]ma[Y][C]cyan|[R][M][Y]yellow|[R][M]genta|'
     """
     parts = []
     for t in text.split(stop):
         if not t:
             continue
         parts.extend([start, t, stop])
     return b''.join(parts)
 
 
 def _render_effects(ui, text, effects):
     """Wrap text in commands to turn on each effect."""
     if not text:
         return text
     if ui._terminfoparams:
         start = b''.join(
             _effect_str(ui, effect) for effect in [b'none'] + effects.split()
         )
         stop = _effect_str(ui, b'none')
     else:
         activeeffects = _activeeffects(ui)
         start = [
             pycompat.bytestr(activeeffects[e])
             for e in [b'none'] + effects.split()
         ]
         start = b'\033[' + b';'.join(start) + b'm'
         stop = b'\033[' + pycompat.bytestr(activeeffects[b'none']) + b'm'
     return _mergeeffects(text, start, stop)
 
 
 _ansieffectre = re.compile(br'\x1b\[[0-9;]*m')
 
 
 def stripeffects(text):
     """Strip ANSI control codes which could be inserted by colorlabel()"""
     return _ansieffectre.sub(b'', text)
 
 
 def colorlabel(ui, msg, label):
     """add color control code according to the mode"""
     if ui._colormode == b'debug':
         if label and msg:
             if msg.endswith(b'\n'):
                 msg = b"[%s|%s]\n" % (label, msg[:-1])
             else:
                 msg = b"[%s|%s]" % (label, msg)
     elif ui._colormode is not None:
         effects = []
         for l in label.split():
             s = ui._styles.get(l, b'')
             if s:
                 effects.append(s)
             elif valideffect(ui, l):
                 effects.append(l)
         effects = b' '.join(effects)
         if effects:
             msg = b'\n'.join(
                 [
                     _render_effects(ui, line, effects)
                     for line in msg.split(b'\n')
                 ]
             )
     return msg
 
 
 w32effects = None
 if pycompat.iswindows:
     import ctypes
 
     _kernel32 = ctypes.windll.kernel32  # pytype: disable=module-attr
 
     _WORD = ctypes.c_ushort
 
     _INVALID_HANDLE_VALUE = -1
 
     class _COORD(ctypes.Structure):
         _fields_ = [('X', ctypes.c_short), ('Y', ctypes.c_short)]
 
     class _SMALL_RECT(ctypes.Structure):
         _fields_ = [
             ('Left', ctypes.c_short),
             ('Top', ctypes.c_short),
             ('Right', ctypes.c_short),
             ('Bottom', ctypes.c_short),
         ]
 
     class _CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):
         _fields_ = [
             ('dwSize', _COORD),
             ('dwCursorPosition', _COORD),
             ('wAttributes', _WORD),
             ('srWindow', _SMALL_RECT),
             ('dwMaximumWindowSize', _COORD),
         ]
 
     _STD_OUTPUT_HANDLE = 0xFFFFFFF5  # (DWORD)-11
     _STD_ERROR_HANDLE = 0xFFFFFFF4  # (DWORD)-12
 
     _FOREGROUND_BLUE = 0x0001
     _FOREGROUND_GREEN = 0x0002
     _FOREGROUND_RED = 0x0004
     _FOREGROUND_INTENSITY = 0x0008
 
     _BACKGROUND_BLUE = 0x0010
     _BACKGROUND_GREEN = 0x0020
     _BACKGROUND_RED = 0x0040
     _BACKGROUND_INTENSITY = 0x0080
 
     _COMMON_LVB_REVERSE_VIDEO = 0x4000
     _COMMON_LVB_UNDERSCORE = 0x8000
 
     # http://msdn.microsoft.com/en-us/library/ms682088%28VS.85%29.aspx
     w32effects = {
         b'none': -1,
         b'black': 0,
         b'red': _FOREGROUND_RED,
         b'green': _FOREGROUND_GREEN,
         b'yellow': _FOREGROUND_RED | _FOREGROUND_GREEN,
         b'blue': _FOREGROUND_BLUE,
         b'magenta': _FOREGROUND_BLUE | _FOREGROUND_RED,
         b'cyan': _FOREGROUND_BLUE | _FOREGROUND_GREEN,
         b'white': _FOREGROUND_RED | _FOREGROUND_GREEN | _FOREGROUND_BLUE,
         b'bold': _FOREGROUND_INTENSITY,
         b'black_background': 0x100,  # unused value > 0x0f
         b'red_background': _BACKGROUND_RED,
         b'green_background': _BACKGROUND_GREEN,
         b'yellow_background': _BACKGROUND_RED | _BACKGROUND_GREEN,
         b'blue_background': _BACKGROUND_BLUE,
         b'purple_background': _BACKGROUND_BLUE | _BACKGROUND_RED,
         b'cyan_background': _BACKGROUND_BLUE | _BACKGROUND_GREEN,
         b'white_background': (
             _BACKGROUND_RED | _BACKGROUND_GREEN | _BACKGROUND_BLUE
         ),
         b'bold_background': _BACKGROUND_INTENSITY,
         b'underline': _COMMON_LVB_UNDERSCORE,  # double-byte charsets only
         b'inverse': _COMMON_LVB_REVERSE_VIDEO,  # double-byte charsets only
     }
 
     passthrough = {
         _FOREGROUND_INTENSITY,
         _BACKGROUND_INTENSITY,
         _COMMON_LVB_UNDERSCORE,
         _COMMON_LVB_REVERSE_VIDEO,
     }
 
     stdout = _kernel32.GetStdHandle(
         _STD_OUTPUT_HANDLE
     )  # don't close the handle returned
     if stdout is None or stdout == _INVALID_HANDLE_VALUE:
         w32effects = None
     else:
         csbi = _CONSOLE_SCREEN_BUFFER_INFO()
         if not _kernel32.GetConsoleScreenBufferInfo(stdout, ctypes.byref(csbi)):
             # stdout may not support GetConsoleScreenBufferInfo()
             # when called from subprocess or redirected
             w32effects = None
         else:
             origattr = csbi.wAttributes
             ansire = re.compile(
                 br'\033\[([^m]*)m([^\033]*)(.*)', re.MULTILINE | re.DOTALL
             )
 
     def win32print(ui, writefunc, text, **opts):
         label = opts.get('label', b'')
         attr = origattr
 
         def mapcolor(val, attr):
             if val == -1:
                 return origattr
             elif val in passthrough:
                 return attr | val
             elif val > 0x0F:
                 return (val & 0x70) | (attr & 0x8F)
             else:
                 return (val & 0x07) | (attr & 0xF8)
 
         # determine console attributes based on labels
         for l in label.split():
             style = ui._styles.get(l, b'')
             for effect in style.split():
                 try:
                     attr = mapcolor(w32effects[effect], attr)
                 except KeyError:
                     # w32effects could not have certain attributes so we skip
                     # them if not found
                     pass
         # hack to ensure regexp finds data
         if not text.startswith(b'\033['):
             text = b'\033[m' + text
 
         # Look for ANSI-like codes embedded in text
         m = re.match(ansire, text)
 
         try:
             while m:
                 for sattr in m.group(1).split(b';'):
                     if sattr:
                         attr = mapcolor(int(sattr), attr)
                 ui.flush()
                 _kernel32.SetConsoleTextAttribute(stdout, attr)
                 writefunc(m.group(2))
                 m = re.match(ansire, m.group(3))
         finally:
             # Explicitly reset original attributes
             ui.flush()
             _kernel32.SetConsoleTextAttribute(stdout, origattr)