python · eamanu · Jun 10, 2022 · Jun 10, 2022 · Jun 10, 2022 · Jun 10, 2022
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
@@ -1181,12 +1181,12 @@ are always available.  They are listed here in alphabetical order.
   *buffering* is an optional integer used to set the buffering policy.  Pass 0
   to switch buffering off (only allowed in binary mode), 1 to select line
   buffering (only usable in text mode), and an integer > 1 to indicate the size
-   in bytes of a fixed-size chunk buffer. Note that specifying a buffer size this
-   way applies for binary buffered I/O, but ``TextIOWrapper`` (i.e., files opened
-   with ``mode='r+'``) would have another buffering. To disable buffering in
-   ``TextIOWrapper``, consider using the ``write_through`` flag for
-   :func:`io.TextIOWrapper.reconfigure`. When no *buffering* argument is
-   given, the default buffering policy works as follows:
+   in bytes of a fixed-size chunk buffer, or -1 to use the default buffer size.
+   Note that specifying a buffer size this way applies for binary buffered I/O,
+   but ``TextIOWrapper`` (i.e., files opened with ``mode='r+'``) would have
+   another buffering. To disable buffering in ``TextIOWrapper``, consider using
+   the ``write_through`` flag for :func:`io.TextIOWrapper.reconfigure`. When no
+   *buffering* argument is given, the default buffering policy works as follows:

   * Binary files are buffered in fixed-size chunks; the size of the buffer is
     chosen using a heuristic trying to determine the underlying device's "block

diff --git a/Lib/_pyio.py b/Lib/_pyio.py
@@ -123,8 +123,9 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
    buffering is an optional integer used to set the buffering policy.
    Pass 0 to switch buffering off (only allowed in binary mode), 1 to select
    line buffering (only usable in text mode), and an integer > 1 to indicate
-    the size of a fixed-size chunk buffer.  When no buffering argument is
-    given, the default buffering policy works as follows:
+    the size of a fixed-size chunk buffer, or-1 to use the default buffer size.
+    When no buffering argument is given, the default buffering policy works as
+    follows:

    * Binary files are buffered in fixed-size chunks; the size of the buffer
      is chosen using a heuristic trying to determine the underlying device's

diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
@@ -124,8 +124,9 @@ platform-dependent encoding or using the specified encoding if given.
 buffering is an optional integer used to set the buffering policy.
 Pass 0 to switch buffering off (only allowed in binary mode), 1 to select
 line buffering (only usable in text mode), and an integer > 1 to indicate
-the size of a fixed-size chunk buffer.  When no buffering argument is
-given, the default buffering policy works as follows:
+the size of a fixed-size chunk buffer, or -1 to use the default buffer
+size.  When no buffering argument is given, the default buffering policy
+works as follows:

 * Binary files are buffered in fixed-size chunks; the size of the buffer
  is chosen using a heuristic trying to determine the underlying device's

diff --git a/Modules/_io/clinic/_iomodule.c.h b/Modules/_io/clinic/_iomodule.c.h