From 9478e96bb98bb1a932997fb4ad1571ddb43ba04e Mon Sep 17 00:00:00 2001
From: Travis Abendshien <46939827+CyanVoxel@users.noreply.github.com>
Date: Mon, 14 Sep 2026 21:10:36 -0700
Subject: [PATCH] perf: skip NFD normalization for ASCII paths

---
 src/tagstudio/core/utils/normalization.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tagstudio/core/utils/normalization.py b/src/tagstudio/core/utils/normalization.py
index 3ba17230..eec71353 100644
--- a/src/tagstudio/core/utils/normalization.py
+++ b/src/tagstudio/core/utils/normalization.py
@@ -10,7 +10,10 @@ def norm_path(path: Path | str, case_sensitive: bool) -> Path:
     """Return `path` normalized to Unicode Normalization Form D (NFD)."""
     if isinstance(path, str):
         path = Path(path)
-    normalized = unicodedata.normalize("NFD", path.as_posix())
+    posix = path.as_posix()
+    # NOTE: ASCII paths will be unaffected by all unicode normalization and can be skipped.
+    # See: https://unicode.org/reports/tr15/
+    normalized = posix if posix.isascii() else unicodedata.normalize("NFD", posix)
     if not case_sensitive:
         normalized = normalized.casefold()
     return Path(normalized)