Merged revisions 80544 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r80544 | benjamin.peterson | 2010-04-27 16:01:54 -0500 (Tue, 27 Apr 2010) | 1 line

  reject None as the buffering argument like the C implementation does #8546
........
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index c58548e..c9c4297 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -35,7 +35,7 @@
         self.characters_written = characters_written
 
 
-def open(file: (str, bytes), mode: str = "r", buffering: int = None,
+def open(file: (str, bytes), mode: str = "r", buffering: int = -1,
          encoding: str = None, errors: str = None,
          newline: str = None, closefd: bool = True) -> "IOBase":
 
@@ -150,7 +150,7 @@
         raise TypeError("invalid file: %r" % file)
     if not isinstance(mode, str):
         raise TypeError("invalid mode: %r" % mode)
-    if buffering is not None and not isinstance(buffering, int):
+    if not isinstance(buffering, int):
         raise TypeError("invalid buffering: %r" % buffering)
     if encoding is not None and not isinstance(encoding, str):
         raise TypeError("invalid encoding: %r" % encoding)
@@ -187,8 +187,6 @@
                  (appending and "a" or "") +
                  (updating and "+" or ""),
                  closefd)
-    if buffering is None:
-        buffering = -1
     line_buffering = False
     if buffering == 1 or buffering < 0 and raw.isatty():
         buffering = -1