diff --git a/git/index/base.py b/git/index/base.py
@@ -4,6 +4,7 @@
# This module is part of GitPython and is released under
# the BSD License: http://www.opensource.org/licenses/bsd-license.php

import datetime
import glob
from io import BytesIO
@@ -352,27 +353,22 @@ def from_tree(cls, repo: "Repo", *treeish: Treeish, **kwargs: Any) -> "IndexFile

        # tmp file created in git home directory to be sure renaming
        # works - /tmp/ dirs could be on another device
-        tmp_index = tempfile.mktemp("", "", repo.git_dir)
-        arg_list.append("--index-output=%s" % tmp_index)
-        arg_list.extend(treeish)
-
-        # move current index out of the way - otherwise the merge may fail
-        # as it considers existing entries. moving it essentially clears the index.
-        # Unfortunately there is no 'soft' way to do it.
-        # The TemporaryFileSwap assure the original file get put back
-        if repo.git_dir:
-            index_handler = TemporaryFileSwap(join_path_native(repo.git_dir, "index"))
-        try:
            repo.git.read_tree(*arg_list, **kwargs)
-            index = cls(repo, tmp_index)
            index.entries  # force it to read the file as we will delete the temp-file
-            del index_handler  # release as soon as possible
-        finally:
-            if osp.exists(tmp_index):
-                os.remove(tmp_index)
-        # END index merge handling
-
-        return index

    # UTILITIES
    @unbare_repo
@@ -1156,7 +1152,6 @@ def checkout(
        unknown_lines = []

        def handle_stderr(proc: "Popen[bytes]", iter_checked_out_files: Iterable[PathLike]) -> None:
-
            stderr_IO = proc.stderr
            if not stderr_IO:
                return None  # return early if stderr empty

diff --git a/git/index/util.py b/git/index/util.py
@@ -3,6 +3,7 @@
import os
import struct
import tempfile

from git.compat import is_win

@@ -11,7 +12,7 @@

# typing ----------------------------------------------------------------------

-from typing import Any, Callable, TYPE_CHECKING

from git.types import PathLike, _T

@@ -47,12 +48,21 @@ def __init__(self, file_path: PathLike) -> None:
        except OSError:
            pass

-    def __del__(self) -> None:
        if osp.isfile(self.tmp_file_path):
            if is_win and osp.exists(self.file_path):
                os.remove(self.file_path)
            os.rename(self.tmp_file_path, self.file_path)
-        # END temp file exists


# { Decorators