Check for mode in some methods

Author: Avasam

setuptools/command/easy_install.py

@@ -75,7 +75,7 @@
 )
 import pkg_resources
 from ..compat import py311
-from ..compat.encoding import encoding_for_open
+from ..compat.encoding import encoding_for_open, encoding_for_open_for_mode
 from .._path import ensure_directory
 from ..extern.jaraco.text import yield_lines
 
@@ -872,7 +872,7 @@ def write_script(self, script_name, contents, mode="t", blockers=()):
         ensure_directory(target)
         if os.path.exists(target):
             os.unlink(target)
-        with open(target, "w" + mode, encoding=encoding_for_open) as f:
+        with open(target, "w" + mode, encoding=encoding_for_open_for_mode(mode)) as f:
             f.write(contents)
         chmod(target, 0o777 - mask)
 

setuptools/compat/encoding.py

@@ -1,5 +1,6 @@
 import locale
 import sys
+from typing import Optional
 
 
 encoding_for_open = (
@@ -10,6 +11,16 @@
 to reduce the amount of `EncodingWarning` in tests logs.
 """
 
+
+def encoding_for_open_for_mode(mode: str) -> Optional[str]:
+    """
+    This method exists to centralize calls to `getpreferredencoding`
+    to reduce the amount of `EncodingWarning` in tests logs,
+    whilst ensuring no encoding is passed to binary mode.
+    """
+    return None if "b" in mode else encoding_for_open
+
+
 encoding_for_pth = locale.getencoding() if sys.version_info >= (3, 11) else None
 """
 When working with ``.pth`` files, let's ignore UTF-8 mode (``PYTHONUTF8`` or ``python -X utf8``)

setuptools/sandbox.py

@@ -13,7 +13,7 @@
 import pkg_resources
 from distutils.errors import DistutilsError
 from pkg_resources import working_set
-from .compat.encoding import encoding_for_open
+from .compat.encoding import encoding_for_open_for_mode
 
 if sys.platform.startswith('java'):
     import org.python.modules.posix.PosixModule as _os
@@ -451,7 +451,8 @@ def _file(self, path, mode='r', *args, **kw):
     def _open(self, path, mode='r', *args, **kw):
         if mode not in ('r', 'rt', 'rb', 'rU', 'U') and not self._ok(path):
             self._violation("open", path, mode, *args, **kw)
-        return _open(path, mode, *args, **kw, encoding=encoding_for_open)
+        kw.setdefault("encoding", encoding_for_open_for_mode(mode))
+        return _open(path, mode, *args, **kw)
 
     def tmpnam(self):
         self._violation("tmpnam")