diff -r 04d5cde28a7f -r 9ed281bbf864 mercurial/hgweb/request.py
--- a/mercurial/hgweb/request.py	Mon Aug 07 11:05:43 2023 +0200
+++ b/mercurial/hgweb/request.py	Mon Aug 07 23:12:02 2023 +0200
@@ -11,7 +11,6 @@
 
 from ..thirdparty import attr
 from .. import (
-    encoding,
     error,
     pycompat,
     util,
@@ -167,13 +166,7 @@
     def tobytes(s):
         if not isinstance(s, str):
             return s
-        if pycompat.iswindows:
-            # This is what mercurial.encoding does for os.environ on
-            # Windows.
-            return encoding.strtolocal(s)
-        else:
-            # This is what is documented to be used for os.environ on Unix.
-            return pycompat.fsencode(s)
+        return s.encode('iso8859-1')
 
     env = {tobytes(k): tobytes(v) for k, v in env.items()}