extdiff: allow modifications in subrepos to be copied back

This check was a legacy bit from when the file data was being fetched manually
with 'ctx[wfn]', but archive() does that now.  49966b5ab16f seems to indicate
that this avoided a problem where a merge adds a file to another branch, and
that test still passes.

Unfortunately, I don't see a way to create a test that modifies the file in the
temporary directory before the command exits.

I wonder if the os.lstat() call needs to be wrapped in an exception handler for
the case where archive didn't create a file because the file didn't exist in
that revision.  But I wasn't able to trigger a problem without it on a real
repository.

hgext/extdiff.py

@@ -1,353 +1,349
 # extdiff.py - external diff program support for mercurial
 #
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''command to allow external programs to compare revisions
 
 The extdiff Mercurial extension allows you to use external programs
 to compare revisions, or revision with working directory. The external
 diff programs are called with a configurable set of options and two
 non-option arguments: paths to directories containing snapshots of
 files to compare.
 
 The extdiff extension also allows you to configure new diff commands, so
 you do not need to type :hg:`extdiff -p kdiff3` always. ::
 
   [extdiff]
   # add new command that runs GNU diff(1) in 'context diff' mode
   cdiff = gdiff -Nprc5
   ## or the old way:
   #cmd.cdiff = gdiff
   #opts.cdiff = -Nprc5
 
   # add new command called meld, runs meld (no need to name twice).  If
   # the meld executable is not available, the meld tool in [merge-tools]
   # will be used, if available
   meld =
 
   # add new command called vimdiff, runs gvimdiff with DirDiff plugin
   # (see http://www.vim.org/scripts/script.php?script_id=102) Non
   # English user, be sure to put "let g:DirDiffDynamicDiffText = 1" in
   # your .vimrc
   vimdiff = gvim -f "+next" \\
             "+execute 'DirDiff' fnameescape(argv(0)) fnameescape(argv(1))"
 
 Tool arguments can include variables that are expanded at runtime::
 
   $parent1, $plabel1 - filename, descriptive label of first parent
   $child,   $clabel  - filename, descriptive label of child revision
   $parent2, $plabel2 - filename, descriptive label of second parent
   $root              - repository root
   $parent is an alias for $parent1.
 
 The extdiff extension will look in your [diff-tools] and [merge-tools]
 sections for diff tool arguments, when none are specified in [extdiff].
 
 ::
 
   [extdiff]
   kdiff3 =
 
   [diff-tools]
   kdiff3.diffargs=--L1 '$plabel1' --L2 '$clabel' $parent $child
 
 You can use -I/-X and list of file or directory names like normal
 :hg:`diff` command. The extdiff extension makes snapshots of only
 needed files, so running the external diff program will actually be
 pretty fast (at least faster than having to compare the entire tree).
 '''
 
 from mercurial.i18n import _
 from mercurial.node import short, nullid
 from mercurial import cmdutil, scmutil, util, commands, encoding, filemerge
 from mercurial import archival
 import os, shlex, shutil, tempfile, re
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 # Note for extension authors: ONLY specify testedwith = 'internal' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'internal'
 
 def snapshot(ui, repo, files, node, tmproot, listsubrepos):
     '''snapshot files as of some revision
     if not using snapshot, -I/-X does not work and recursive diff
     in tools like kdiff3 and meld displays too many files.'''
     dirname = os.path.basename(repo.root)
     if dirname == "":
         dirname = "root"
     if node is not None:
         dirname = '%s.%s' % (dirname, short(node))
     base = os.path.join(tmproot, dirname)
     os.mkdir(base)
     fns_and_mtime = []
 
     if node is not None:
         ui.note(_('making snapshot of %d files from rev %s\n') %
                 (len(files), short(node)))
     else:
         ui.note(_('making snapshot of %d files from working directory\n') %
             (len(files)))
 
     if files:
         repo.ui.setconfig("ui", "archivemeta", False)
 
         archival.archive(repo, base, node, 'files',
                          matchfn=scmutil.matchfiles(repo, files),
                          subrepos=listsubrepos)
 
-        ctx = repo[node]
         for fn in sorted(files):
             wfn = util.pconvert(fn)
-            if wfn not in ctx:
-                # File doesn't exist; could be a bogus modify
-                continue
             ui.note('  %s\n' % wfn)
 
             if node is None:
                 dest = os.path.join(base, wfn)
 
                 fns_and_mtime.append((dest, repo.wjoin(fn),
                                       os.lstat(dest).st_mtime))
     return dirname, fns_and_mtime
 
 def dodiff(ui, repo, cmdline, pats, opts):
     '''Do the actual diff:
 
     - copy to a temp structure if diffing 2 internal revisions
     - copy to a temp structure if diffing working revision with
       another one and more than 1 file is changed
     - just invoke the diff for a single file in the working dir
     '''
 
     revs = opts.get('rev')
     change = opts.get('change')
     do3way = '$parent2' in cmdline
 
     if revs and change:
         msg = _('cannot specify --rev and --change at the same time')
         raise util.Abort(msg)
     elif change:
         node2 = scmutil.revsingle(repo, change, None).node()
         node1a, node1b = repo.changelog.parents(node2)
     else:
         node1a, node2 = scmutil.revpair(repo, revs)
         if not revs:
             node1b = repo.dirstate.p2()
         else:
             node1b = nullid
 
     # Disable 3-way merge if there is only one parent
     if do3way:
         if node1b == nullid:
             do3way = False
 
     subrepos=opts.get('subrepos')
 
     matcher = scmutil.match(repo[node2], pats, opts)
     mod_a, add_a, rem_a = map(set, repo.status(node1a, node2, matcher,
                                                listsubrepos=subrepos)[:3])
     if do3way:
         mod_b, add_b, rem_b = map(set, repo.status(node1b, node2, matcher,
                                                    listsubrepos=subrepos)[:3])
     else:
         mod_b, add_b, rem_b = set(), set(), set()
     modadd = mod_a | add_a | mod_b | add_b
     common = modadd | rem_a | rem_b
     if not common:
         return 0
 
     tmproot = tempfile.mkdtemp(prefix='extdiff.')
     try:
         # Always make a copy of node1a (and node1b, if applicable)
         dir1a_files = mod_a | rem_a | ((mod_b | add_b) - add_a)
         dir1a = snapshot(ui, repo, dir1a_files, node1a, tmproot, subrepos)[0]
         rev1a = '@%d' % repo[node1a].rev()
         if do3way:
             dir1b_files = mod_b | rem_b | ((mod_a | add_a) - add_b)
             dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot,
                              subrepos)[0]
             rev1b = '@%d' % repo[node1b].rev()
         else:
             dir1b = None
             rev1b = ''
 
         fns_and_mtime = []
 
         # If node2 in not the wc or there is >1 change, copy it
         dir2root = ''
         rev2 = ''
         if node2:
             dir2 = snapshot(ui, repo, modadd, node2, tmproot, subrepos)[0]
             rev2 = '@%d' % repo[node2].rev()
         elif len(common) > 1:
             #we only actually need to get the files to copy back to
             #the working dir in this case (because the other cases
             #are: diffing 2 revisions or single file -- in which case
             #the file is already directly passed to the diff tool).
             dir2, fns_and_mtime = snapshot(ui, repo, modadd, None, tmproot,
                                            subrepos)
         else:
             # This lets the diff tool open the changed file directly
             dir2 = ''
             dir2root = repo.root
 
         label1a = rev1a
         label1b = rev1b
         label2 = rev2
 
         # If only one change, diff the files instead of the directories
         # Handle bogus modifies correctly by checking if the files exist
         if len(common) == 1:
             common_file = util.localpath(common.pop())
             dir1a = os.path.join(tmproot, dir1a, common_file)
             label1a = common_file + rev1a
             if not os.path.isfile(dir1a):
                 dir1a = os.devnull
             if do3way:
                 dir1b = os.path.join(tmproot, dir1b, common_file)
                 label1b = common_file + rev1b
                 if not os.path.isfile(dir1b):
                     dir1b = os.devnull
             dir2 = os.path.join(dir2root, dir2, common_file)
             label2 = common_file + rev2
 
         # Function to quote file/dir names in the argument string.
         # When not operating in 3-way mode, an empty string is
         # returned for parent2
         replace = {'parent': dir1a, 'parent1': dir1a, 'parent2': dir1b,
                    'plabel1': label1a, 'plabel2': label1b,
                    'clabel': label2, 'child': dir2,
                    'root': repo.root}
         def quote(match):
             pre = match.group(2)
             key = match.group(3)
             if not do3way and key == 'parent2':
                 return pre
             return pre + util.shellquote(replace[key])
 
         # Match parent2 first, so 'parent1?' will match both parent1 and parent
         regex = (r'''(['"]?)([^\s'"$]*)'''
                  r'\$(parent2|parent1?|child|plabel1|plabel2|clabel|root)\1')
         if not do3way and not re.search(regex, cmdline):
             cmdline += ' $parent1 $child'
         cmdline = re.sub(regex, quote, cmdline)
 
         ui.debug('running %r in %s\n' % (cmdline, tmproot))
         ui.system(cmdline, cwd=tmproot)
 
         for copy_fn, working_fn, mtime in fns_and_mtime:
             if os.lstat(copy_fn).st_mtime != mtime:
                 ui.debug('file changed while diffing. '
                          'Overwriting: %s (src: %s)\n' % (working_fn, copy_fn))
                 util.copyfile(copy_fn, working_fn)
 
         return 1
     finally:
         ui.note(_('cleaning up temp directory\n'))
         shutil.rmtree(tmproot)
 
 @command('extdiff',
     [('p', 'program', '',
      _('comparison program to run'), _('CMD')),
     ('o', 'option', [],
      _('pass option to comparison program'), _('OPT')),
     ('r', 'rev', [], _('revision'), _('REV')),
     ('c', 'change', '', _('change made by revision'), _('REV')),
     ] + commands.walkopts + commands.subrepoopts,
     _('hg extdiff [OPT]... [FILE]...'),
     inferrepo=True)
 def extdiff(ui, repo, *pats, **opts):
     '''use external program to diff repository (or selected files)
 
     Show differences between revisions for the specified files, using
     an external program. The default program used is diff, with
     default options "-Npru".
 
     To select a different program, use the -p/--program option. The
     program will be passed the names of two directories to compare. To
     pass additional options to the program, use -o/--option. These
     will be passed before the names of the directories to compare.
 
     When two revision arguments are given, then changes are shown
     between those revisions. If only one revision is specified then
     that revision is compared to the working directory, and, when no
     revisions are specified, the working directory files are compared
     to its parent.'''
     program = opts.get('program')
     option = opts.get('option')
     if not program:
         program = 'diff'
         option = option or ['-Npru']
     cmdline = ' '.join(map(util.shellquote, [program] + option))
     return dodiff(ui, repo, cmdline, pats, opts)
 
 def uisetup(ui):
     for cmd, path in ui.configitems('extdiff'):
         path = util.expandpath(path)
         if cmd.startswith('cmd.'):
             cmd = cmd[4:]
             if not path:
                 path = util.findexe(cmd)
                 if path is None:
                     path = filemerge.findexternaltool(ui, cmd) or cmd
             diffopts = ui.config('extdiff', 'opts.' + cmd, '')
             cmdline = util.shellquote(path)
             if diffopts:
                 cmdline += ' ' + diffopts
         elif cmd.startswith('opts.'):
             continue
         else:
             if path:
                 # case "cmd = path opts"
                 cmdline = path
                 diffopts = len(shlex.split(cmdline)) > 1
             else:
                 # case "cmd ="
                 path = util.findexe(cmd)
                 if path is None:
                     path = filemerge.findexternaltool(ui, cmd) or cmd
                 cmdline = util.shellquote(path)
                 diffopts = False
         # look for diff arguments in [diff-tools] then [merge-tools]
         if not diffopts:
             args = ui.config('diff-tools', cmd+'.diffargs') or \
                    ui.config('merge-tools', cmd+'.diffargs')
             if args:
                 cmdline += ' ' + args
         def save(cmdline):
             '''use closure to save diff command to use'''
             def mydiff(ui, repo, *pats, **opts):
                 options = ' '.join(map(util.shellquote, opts['option']))
                 if options:
                     options = ' ' + options
                 return dodiff(ui, repo, cmdline + options, pats, opts)
             doc = _('''\
 use %(path)s to diff repository (or selected files)
 
     Show differences between revisions for the specified files, using
     the %(path)s program.
 
     When two revision arguments are given, then changes are shown
     between those revisions. If only one revision is specified then
     that revision is compared to the working directory, and, when no
     revisions are specified, the working directory files are compared
     to its parent.\
 ''') % {'path': util.uirepr(path)}
 
             # We must translate the docstring right away since it is
             # used as a format string. The string will unfortunately
             # be translated again in commands.helpcmd and this will
             # fail when the docstring contains non-ASCII characters.
             # Decoding the string to a Unicode string here (using the
             # right encoding) prevents that.
             mydiff.__doc__ = doc.decode(encoding.encoding)
             return mydiff
         cmdtable[cmd] = (save(cmdline),
                          cmdtable['extdiff'][1][1:],
                          _('hg %s [OPTION]... [FILE]...') % cmd)