[3.14] gh-128066: Properly handle history file writes for RO fs on PyREPL (gh-134380) (gh-134385)

miss-islington · feoh · ambv · web-flow · commit 379805d03c7e · 2025-05-20T22:15:23.000+02:00
(cherry picked from commit c91ad5d) Co-authored-by: Chris Patti <feoh@feoh.org> Co-authored-by: Łukasz Langa <lukasz@langa.pl>
diff --git a/Lib/_pyrepl/simple_interact.py b/Lib/_pyrepl/simple_interact.py
@@ -31,6 +31,7 @@
 import sys
 import code
 import warnings
+import errno
 
 from .readline import _get_reader, multiline_input, append_history_file
 
@@ -153,6 +154,7 @@ def maybe_run_command(statement: str) -> bool:
                 append_history_file()
             except (FileNotFoundError, PermissionError, OSError) as e:
                 warnings.warn(f"failed to open the history file for writing: {e}")
+
             input_n += 1
         except KeyboardInterrupt:
             r = _get_reader()
diff --git a/Lib/site.py b/Lib/site.py
@@ -75,6 +75,7 @@
 import _sitebuiltins
 import _io as io
 import stat
+import errno
 
 # Prefixes for site-packages; add additional prefixes like /usr/local here
 PREFIXES = [sys.prefix, sys.exec_prefix]
@@ -578,10 +579,15 @@ def register_readline():
         def write_history():
             try:
                 readline_module.write_history_file(history)
-            except (FileNotFoundError, PermissionError):
+            except FileNotFoundError, PermissionError:
                 # home directory does not exist or is not writable
                 # https://bugs.python.org/issue19891
                 pass
+            except OSError:
+                if errno.EROFS:
+                    pass  # gh-128066: read-only file system
+                else:
+                    raise
 
         atexit.register(write_history)
 
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-05-20-14-41-50.gh-issue-128066.qzzGfv.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-20-14-41-50.gh-issue-128066.qzzGfv.rst
@@ -0,0 +1,3 @@
+Fixes an edge case where PyREPL improperly threw an error when Python is
+invoked on a read only filesystem while trying to write history file
+entries.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+Fixes an edge case where PyREPL improperly threw an error when Python is`
	`2`	`+invoked on a read only filesystem while trying to write history file`
	`3`	`+entries.`