From e9a5fc6809c679b4c4d542ea90b552d60188c4f3 Mon Sep 17 00:00:00 2001
From: Chris Eibl <138194463+chris-eibl@users.noreply.github.com>
Date: Tue, 23 Sep 2025 16:36:20 +0200
Subject: [PATCH 1/2] fix occasionally swalled keystrokes on Windows

---
 Lib/_pyrepl/windows_console.py               | 11 ++++++++-
 Lib/test/test_pyrepl/test_windows_console.py | 26 ++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/Lib/_pyrepl/windows_console.py b/Lib/_pyrepl/windows_console.py
index c56dcd6d7dd434..893cc0580d1608 100644
--- a/Lib/_pyrepl/windows_console.py
+++ b/Lib/_pyrepl/windows_console.py
@@ -566,7 +566,7 @@ def getpending(self) -> Event:
                 e.data += ch
         return e
 
-    def wait(self, timeout: float | None) -> bool:
+    def wait_for_event(self, timeout: float | None) -> bool:
         """Wait for an event."""
         if timeout is None:
             timeout = INFINITE
@@ -579,6 +579,15 @@ def wait(self, timeout: float | None) -> bool:
             return False
         return True
 
+    def wait(self, timeout: float | None) -> bool:
+        """
+        Wait for events on the console.
+        """
+        return (
+            not self.event_queue.empty()
+            or self.wait_for_event(timeout)
+        )
+
     def repaint(self) -> None:
         raise NotImplementedError("No repaint support")
 
diff --git a/Lib/test/test_pyrepl/test_windows_console.py b/Lib/test/test_pyrepl/test_windows_console.py
index f9607e02c604ff..e36d3259a889b8 100644
--- a/Lib/test/test_pyrepl/test_windows_console.py
+++ b/Lib/test/test_pyrepl/test_windows_console.py
@@ -576,6 +576,32 @@ def test_up_vt(self):
                          Event(evt='key', data='up', raw=bytearray(b'\x1b[A')))
         self.assertEqual(self.mock.call_count, 3)
 
+    # All tests above assume that there is always keyboard data to read,
+    # because for simplicity we just use
+    # self.console.wait = MagicMock(return_value=True)
+    def test_wait_empty(self):
+        console = WindowsConsole(encoding='utf-8')
+        console.wait_for_event = MagicMock(return_value=True)
+        self.assertTrue(console.event_queue.empty())
+        timeout = 2.0
+        self.assertTrue(console.wait(timeout))
+        self.assertEqual(console.wait_for_event.call_count, 1)
+        self.assertEqual(console.wait_for_event.mock_calls[0], call(timeout))
+
+        timeout = 1.1
+        console.wait_for_event = MagicMock(return_value=False)
+        self.assertFalse(console.wait(timeout))
+        self.assertEqual(console.wait_for_event.call_count, 1)
+        self.assertEqual(console.wait_for_event.mock_calls[0], call(timeout))
+
+    def test_wait_not_empty(self):
+        console = WindowsConsole(encoding='utf-8')
+        console.wait_for_event = MagicMock(return_value=True)
+        console.event_queue.push(b"a")
+        self.assertFalse(console.event_queue.empty())
+        self.assertTrue(console.wait(0.0))
+        self.assertEqual(console.wait_for_event.call_count, 0)
+
 
 if __name__ == "__main__":
     unittest.main()

From 71ec85a8761077780a6adb751df666c2b5ad0b05 Mon Sep 17 00:00:00 2001
From: Chris Eibl <138194463+chris-eibl@users.noreply.github.com>
Date: Tue, 23 Sep 2025 16:41:46 +0200
Subject: [PATCH 2/2] blurb it

---
 .../next/Library/2025-09-23-16-41-21.gh-issue-139262.RO0E98.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2025-09-23-16-41-21.gh-issue-139262.RO0E98.rst

diff --git a/Misc/NEWS.d/next/Library/2025-09-23-16-41-21.gh-issue-139262.RO0E98.rst b/Misc/NEWS.d/next/Library/2025-09-23-16-41-21.gh-issue-139262.RO0E98.rst
new file mode 100644
index 00000000000000..628fa0e0d53c3e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-23-16-41-21.gh-issue-139262.RO0E98.rst
@@ -0,0 +1,2 @@
+Some keystrokes can be swallowed in the new ``PyREPL`` on Windows,
+especially when used together with the ALT key. Fix by Chris Eibl.