From 4eb8fa58a5fb74f105ce73240b4c7ed34cadfc69 Mon Sep 17 00:00:00 2001
From: Stepan Neretin <slpmcf@gmail.com>
Date: Wed, 11 Jun 2025 05:13:23 +0700
Subject: [PATCH] gh-135329: prevent infinite traceback loop on Ctrl-C under
 external programs

When running Python REPL under another program (e.g., strace) and pressing Ctrl-C,
termios raises `EIO` during terminal state restoration, causing infinite exception tracebacks.

This patch catches `termios.error` with `errno.EIO` in `reader.prepare()` to avoid
recursive failure loops when restoring console state.
---
 Lib/_pyrepl/reader.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Lib/_pyrepl/reader.py b/Lib/_pyrepl/reader.py
index 0ebd9162eca4bb..e1e4c190260190 100644
--- a/Lib/_pyrepl/reader.py
+++ b/Lib/_pyrepl/reader.py
@@ -30,6 +30,8 @@
 from . import commands, console, input
 from .utils import wlen, unbracket, disp_str, gen_colors, THEME
 from .trace import trace
+import termios
+import errno
 
 
 # types
@@ -590,6 +592,10 @@ def prepare(self) -> None:
             self.dirty = True
             self.last_command = None
             self.calc_screen()
+        except termios.error as e:
+            if e.args[0] == errno.EIO:
+                return
+            raise
         except BaseException:
             self.restore()
             raise