43     filemerge,

  1506 @command('debugpickmergetool',

  1507         [('r', 'rev', '', _('check for files in this revision'), _('REV')),

  1508          ('', 'changedelete', None, _('emulate merging change and delete')),

  1509         ] + commands.walkopts + commands.mergetoolopts,

  1510         _('[PATTERN]...'),

  1511         inferrepo=True)

  1512 def debugpickmergetool(ui, repo, *pats, **opts):

  1513     """examine which merge tool is chosen for specified file

  1514 

  1515     As described in :hg:`help merge-tools`, Mercurial examines

  1516     configurations below in this order to decide which merge tool is

  1517     chosen for specified file.

  1518 

  1519     1. ``--tool`` option

  1520     2. ``HGMERGE`` environment variable

  1521     3. configurations in ``merge-patterns`` section

  1522     4. configuration of ``ui.merge``

  1523     5. configurations in ``merge-tools`` section

  1524     6. ``hgmerge`` tool (for historical reason only)

  1525     7. default tool for fallback (``:merge`` or ``:prompt``)

  1526 

  1527     This command writes out examination result in the style below::

  1528 

  1529         FILE = MERGETOOL

  1530 

  1531     By default, all files known in the first parent context of the

  1532     working directory are examined. Use file patterns and/or -I/-X

  1533     options to limit target files. -r/--rev is also useful to examine

  1534     files in another context without actual updating to it.

  1535 

  1536     With --debug, this command shows warning messages while matching

  1537     against ``merge-patterns`` and so on, too. It is recommended to

  1538     use this option with explicit file patterns and/or -I/-X options,

  1539     because this option increases amount of output per file according

  1540     to configurations in hgrc.

  1541 

  1542     With -v/--verbose, this command shows configurations below at

  1543     first (only if specified).

  1544 

  1545     - ``--tool`` option

  1546     - ``HGMERGE`` environment variable

  1547     - configuration of ``ui.merge``

  1548 

  1549     If merge tool is chosen before matching against

  1550     ``merge-patterns``, this command can't show any helpful

  1551     information, even with --debug. In such case, information above is

  1552     useful to know why a merge tool is chosen.

  1553     """

  1554     overrides = {}

  1555     if opts['tool']:

  1556         overrides[('ui', 'forcemerge')] = opts['tool']

  1557         ui.note(('with --tool %r\n') % (opts['tool']))

  1558 

  1559     with ui.configoverride(overrides, 'debugmergepatterns'):

  1560         hgmerge = encoding.environ.get("HGMERGE")

  1561         if hgmerge is not None:

  1562             ui.note(('with HGMERGE=%r\n') % (hgmerge))

  1563         uimerge = ui.config("ui", "merge")

  1564         if uimerge:

  1565             ui.note(('with ui.merge=%r\n') % (uimerge))

  1566 

  1567         ctx = scmutil.revsingle(repo, opts.get('rev'))

  1568         m = scmutil.match(ctx, pats, opts)

  1569         changedelete = opts['changedelete']

  1570         for path in ctx.walk(m):

  1571             fctx = ctx[path]

  1572             try:

  1573                 if not ui.debugflag:

  1574                     ui.pushbuffer(error=True)

  1575                 tool, toolpath = filemerge._picktool(repo, ui, path,

  1576                                                      fctx.isbinary(),

  1577                                                      'l' in fctx.flags(),

  1578                                                      changedelete)

  1579             finally:

  1580                 if not ui.debugflag:

  1581                     ui.popbuffer()

  1582             ui.write(('%s = %s\n') % (path, tool))

  1583