attempt one

Author: matthewdeanmartin

src/bagit/__init__.py

@@ -131,9 +131,25 @@ def find_locale_dir():
 #: Block size used when reading files for hashing:
 HASH_BLOCK_SIZE = 512 * 1024
 
+
+def open_text_file(filename, mode="r", encoding="utf-8", errors="strict"):
+    # Open the underlying file in binary mode so the codec wrapper keeps codecs.open() behavior without its deprecation.
+    binary_mode = mode.replace("t", "")
+    if "b" not in binary_mode:
+        binary_mode += "b"
+
+    stream = open(filename, binary_mode)
+    if "r" in mode and all(flag not in mode for flag in ("w", "a", "+")):
+        wrapped = codecs.getreader(encoding)(stream, errors=errors)
+    else:
+        wrapped = codecs.getwriter(encoding)(stream, errors=errors)
+
+    wrapped.encoding = codecs.lookup(encoding).name.upper()
+    return wrapped
+
+
 #: Convenience function used everywhere we want to open a file to read text
 #: rather than undecoded bytes:
-open_text_file = partial(codecs.open, encoding="utf-8", errors="strict")
 
 # This is the same as decoding the byte values in codecs.BOM:
 UNICODE_BYTE_ORDER_MARK = "\ufeff"
@@ -1423,8 +1439,8 @@ def _encode_filename(s):
 
 
 def _decode_filename(s):
-    s = re.sub(r"%0D", "\r", s, re.IGNORECASE)
-    s = re.sub(r"%0A", "\n", s, re.IGNORECASE)
+    s = re.sub(r"%0D", "\r", s, flags=re.IGNORECASE)
+    s = re.sub(r"%0A", "\n", s, flags=re.IGNORECASE)
     return s