def getfilectx(repo, memctx, f):
     of = files[f]
     if 'deleted' in of:
         if check_version(3, 2):
             return None
         else:
             raise IOError
     if 'ctx' in of:
         if mode == 'hg':
             ctx = of['ctx']
             is_exec = ctx.isexec()
             is_link = ctx.islink()
             if check_version(3, 1):
                 return context.memfilectx(repo, f, ctx.data(),
                         is_link, is_exec)
             else:
                 return context.memfilectx(f, ctx.data(),
                         is_link, is_exec)
         else:
             return of['ctx']
     is_exec = of['mode'] == 'x'
     is_link = of['mode'] == 'l'
     rename = of.get('rename', None)
     if check_version(3, 1):
         return context.memfilectx(repo, f, of['data'],
                 is_link, is_exec, rename)
     else:
         return context.memfilectx(f, of['data'],
                 is_link, is_exec, rename)

        def filectxfn(_repo, memctx, path):
            """
            Marks given path as added/changed/removed in a given _repo. This is
            for internal mercurial commit function.
            """

            # check if this path is removed
            if path in (node.path for node in self.removed):
                # Raising exception is a way to mark node for removal
                raise IOError(errno.ENOENT, "%s is deleted" % path)

            # check if this path is added
            for node in self.added:
                if node.path == path:
                    return memfilectx(
                        path=node.path,
                        data=node.content.encode("utf8"),
                        islink=False,
                        isexec=node.is_executable,
                        copied=False,
                    )

            # or changed
            for node in self.changed:
                if node.path == path:
                    return memfilectx(
                        path=node.path,
                        data=node.content.encode("utf8"),
                        islink=False,
                        isexec=node.is_executable,
                        copied=False,
                    )

            raise RepositoryError("Given path haven't been marked as added," "changed or removed (%s)" % path)

    def getfilectx(repo, memctx, f):
        if bfutil.is_standin(f):
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            srcfname = bfutil.split_standin(f)
            try:
                fctx = ctx.filectx(srcfname)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                # standin is always a bfile because bfileness
                # doesn't change after rename or copy
                renamed = bfutil.standin(renamed[0])

            return context.memfilectx(f, bfiletohash[srcfname], 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)
        else:
            try:
                fctx = ctx.filectx(f)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = renamed[0]

            data = fctx.data()
            if f == '.hgtags':
                newdata = []
                for line in data.splitlines():
                    id, name = line.split(' ', 1)
                    newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]), name))
                data = ''.join(newdata)
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)

def makememfilectx(repo, path, data, islink, isexec, copied):
    """Return a memfilectx

    Works around memfilectx() adding a repo argument between 3.0 and 3.1.
    """
    from mercurial import context
    try:
        return context.memfilectx(repo, path, data, islink, isexec, copied)
    except TypeError:
        return context.memfilectx(path, data, islink, isexec, copied)

 def file_callback(repo, memctx, path):
     if path == 'adding_file':
         return context.memfilectx(path=path,
                                   data='foo',
                                   islink=False,
                                   isexec=False,
                                   copied=False)
     elif path == 'adding_binary':
         return context.memfilectx(path=path,
                                   data='\0binary',
                                   islink=False,
                                   isexec=False,
                                   copied=False)
     raise IOError(errno.EINVAL, 'Invalid operation: ' + path)

 def hgtagsfn(repo, memctx, path):
     assert path == '.hgtags'
     return context.memfilectx(path=path,
                               data=tagdata,
                               islink=False,
                               isexec=False,
                               copied=False)

    def getfilectx(repo, memctx, f):
        if lfutil.standin(f) in files:
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            try:
                fctx = ctx.filectx(lfutil.standin(f))
            except error.LookupError:
                return None
            renamed = fctx.renamed()
            if renamed:
                renamed = lfutil.splitstandin(renamed[0])

            hash = fctx.data().strip()
            path = lfutil.findfile(rsrc, hash)

            # If one file is missing, likely all files from this rev are
            if path is None:
                cachelfiles(ui, rsrc, ctx.node())
                path = lfutil.findfile(rsrc, hash)

                if path is None:
                    raise util.Abort(_("missing largefile '%s' from revision %s") % (f, node.hex(ctx.node())))

            data = ""
            fd = None
            try:
                fd = open(path, "rb")
                data = fd.read()
            finally:
                if fd:
                    fd.close()
            return context.memfilectx(repo, f, data, "l" in fctx.flags(), "x" in fctx.flags(), renamed)
        else:
            return _getnormalcontext(repo, ctx, f, revmap)

    def filectxfn(repo, memctx, path):
        if path in files_data and files_data[path] is None:
            raise IOError(errno.ENOENT, '%s is deleted' % path)

        if path in binary_files or path in unknown_files:
            pa = path
            if branchpath:
                pa = branchpath + '/' + path
            data, mode = svn.get_file(pa, r.revnum)
            isexe = 'x' in mode
            islink = 'l' in mode
        else:
            isexe = exec_files.get(path, 'x' in parentctx.flags(path))
            islink = link_files.get(path, 'l' in parentctx.flags(path))
            data = ''
            if path in files_data:
                data = files_data[path]
                if islink:
                    data = data[len('link '):]
            elif path in parentctx:
                data = parentctx[path].data()

        copied = copies.get(path)
        # TODO this branch feels like it should not be required,
        # and this may actually imply a bug in getcopies
        if copied not in parentctx.manifest():
            copied = None
        return context.memfilectx(path=path, data=data, islink=islink,
                                  isexec=isexe, copied=copied)

    def getfilectx(repo, memctx, f):
        if lfutil.standin(f) in files:
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            try:
                fctx = ctx.filectx(lfutil.standin(f))
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = lfutil.splitstandin(renamed[0])

            hash = fctx.data().strip()
            path = lfutil.findfile(rsrc, hash)
            ### TODO: What if the file is not cached?
            data = ""
            fd = None
            try:
                fd = open(path, "rb")
                data = fd.read()
            finally:
                if fd:
                    fd.close()
            return context.memfilectx(f, data, "l" in fctx.flags(), "x" in fctx.flags(), renamed)
        else:
            return _getnormalcontext(repo.ui, ctx, f, revmap)

        def getfilectx(repo, memctx, f):
            info = files.get(f)
            if info != None:
                # it's a file reported as modified from Git
                delete, mode, sha = info
                if delete:
                    raise IOError

                if not sha: # indicates there's no git counterpart
                    e = ''
                    copied_path = None
                    if '.hgsubstate' == f:
                        data = util.serialize_hgsubstate(hgsubstate)
                    elif '.hgsub' == f:
                        data = util.serialize_hgsub(hgsub)
                else:
                    data = self.git[sha].data
                    copied_path = hg_renames.get(f)
                    e = self.convert_git_int_mode(mode)
            else:
                # it's a converged file
                fc = context.filectx(self.repo, f, changeid=memctx.p1().rev())
                data = fc.data()
                e = fc.flags()
                copied_path = fc.renamed()

            return context.memfilectx(f, data, 'l' in e, 'x' in e, copied_path)

 def getfilectx(repo, memctx, f):
     v = files[f]
     data, mode = source.getfile(f, v)
     if f == '.hgtags':
         data = self._rewritetags(source, revmap, data)
     return context.memfilectx(f, data, 'l' in mode, 'x' in mode,
                               copies.get(f))

 def cb(repo, memctx, path):
     if path == data:
         return context.memfilectx(path=path,
                                   data=data,
                                   islink=False,
                                   isexec=False,
                                   copied=False)
     raise IOError(errno.EINVAL, 'Invalid operation: ' + path)

 def getfilectx(repo, memctx, name):
     fileid = files[name]
     if fileid is None:  # deleted file
         raise IOError
     data = self.getblob(fileid)
     ctx = context.memfilectx(name, data, 'l' in modes,
                              'x' in modes, copies.get(name))
     return ctx

 def file_callback(repo, memctx, path):
     if path == 'gamma':
         return context.memfilectx(path=path,
                                   data='foo',
                                   islink=True,
                                   isexec=False,
                                   copied=False)
     raise IOError(errno.EINVAL, 'Invalid operation: ' + path)

 def file_callback(repo, memctx, path):
     return context.memfilectx(
         path=path,
         data=items[path],
         islink=False,
         isexec=False,
         copied=False,
         )

 def filectxfn(repo, ctx, path):
     if path in headmf:
         fctx = last[path]
         flags = fctx.flags()
         mctx = context.memfilectx(
             fctx.path(), fctx.data(), islink="l" in flags, isexec="x" in flags, copied=copied.get(path)
         )
         return mctx
     raise IOError()

 def filectxfn(repo, memctx, path):
     if path in externals:
         if externals[path] is None:
             raise IOError(errno.ENOENT, "no externals")
         return context.memfilectx(path=path, data=externals[path], islink=False, isexec=False, copied=None)
     for bad in bad_branch_paths[b]:
         if path.startswith(bad):
             raise IOError(errno.ENOENT, "Path %s is bad" % path)
     return filectxfn2(repo, memctx, path)

    def getfilectx(repo, memctx, f):
        if lfutil.standin(f) in files:
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            try:
                fctx = ctx.filectx(lfutil.standin(f))
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = lfutil.splitstandin(renamed[0])

            hash = fctx.data().strip()
            path = lfutil.findfile(rsrc, hash)
            ### TODO: What if the file is not cached?
            data = ''
            fd = None
            try:
                fd = open(path, 'rb')
                data = fd.read()
            finally:
                if fd:
                    fd.close()
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)
        else:
            try:
                fctx = ctx.filectx(f)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = renamed[0]
            data = fctx.data()
            if f == '.hgtags':
                newdata = []
                for line in data.splitlines():
                    id, name = line.split(' ', 1)
                    newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]),
                        name))
                data = ''.join(newdata)
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)

        def getfilectx(repo, memctx, f):
            delete, mode, sha = files[f]
            if delete:
                raise IOError

            data = self.git[sha].data
            copied_path = hg_renames.get(f)
            e = self.convert_git_int_mode(mode)

            return context.memfilectx(f, data, 'l' in e, 'x' in e, copied_path)

 def filectxfn(repo, ctx, path):
     if path in headmf:
         fctx = head[path]
         flags = fctx.flags()
         mctx = context.memfilectx(repo, ctx, fctx.path(), fctx.data(),
                                   islink='l' in flags,
                                   isexec='x' in flags,
                                   copied=copied.get(path))
         return mctx
     return None