From 0b4c87ef8f88a4c4c325e964fa4919cef3997605 Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Thu, 2 Jul 2020 04:02:16 -0700
Subject: [PATCH] bpo-41193: Ignore OSError in readline write_history()
 (GH-21279)

The write_history() atexit function of the readline completer now
ignores any OSError to ignore error if the filesystem is read-only,
instead of only ignoring FileNotFoundError and PermissionError.
(cherry picked from commit 0ab917e07ed64c6bfde6f6e791f9b28acc97b510)

Co-authored-by: Victor Stinner <vstinner@python.org>
---
 Lib/site.py                                                 | 6 +++---
 .../next/Library/2020-07-02-11-53-45.bpo-41193.8-Tnql.rst   | 4 ++++
 2 files changed, 7 insertions(+), 3 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2020-07-02-11-53-45.bpo-41193.8-Tnql.rst

diff --git a/Lib/site.py b/Lib/site.py
index e981a142088..9e617afb00f 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -453,9 +453,9 @@ def enablerlcompleter():
             def write_history():
                 try:
                     readline.write_history_file(history)
-                except (FileNotFoundError, PermissionError):
-                    # home directory does not exist or is not writable
-                    # https://bugs.python.org/issue19891
+                except OSError:
+                    # bpo-19891, bpo-41193: Home directory does not exist
+                    # or is not writable, or the filesystem is read-only.
                     pass
 
             atexit.register(write_history)
diff --git a/Misc/NEWS.d/next/Library/2020-07-02-11-53-45.bpo-41193.8-Tnql.rst b/Misc/NEWS.d/next/Library/2020-07-02-11-53-45.bpo-41193.8-Tnql.rst
new file mode 100644
index 00000000000..8807d9c21fe
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-07-02-11-53-45.bpo-41193.8-Tnql.rst
@@ -0,0 +1,4 @@
+The ``write_history()`` atexit function of the readline completer now
+ignores any :exc:`OSError` to ignore error if the filesystem is read-only,
+instead of only ignoring :exc:`FileNotFoundError` and
+:exc:`PermissionError`.