gh-146458: Fix REPL height and width tracking on resize (#146459)

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Victor Stinner <vstinner@python.org>

Author: 3 people

Lib/_pyrepl/reader.py

@@ -651,6 +651,7 @@ def update_screen(self) -> None:
 
     def refresh(self) -> None:
         """Recalculate and refresh the screen."""
+        self.console.height, self.console.width = self.console.getheightwidth()
         # this call sets up self.cxy, so call it first.
         self.screen = self.calc_screen()
         self.console.refresh(self.screen, self.cxy)

Lib/_pyrepl/unix_console.py

@@ -776,7 +776,6 @@ def __move_tall(self, x, y):
         self.__write_code(self._cup, y - self.__offset, x)
 
     def __sigwinch(self, signum, frame):
-        self.height, self.width = self.getheightwidth()
         self.event_queue.insert(Event("resize", None))
 
     def __hide_cursor(self):

Lib/test/test_pyrepl/support.py

@@ -88,6 +88,8 @@ def prepare_console(events: Iterable[Event], **kwargs) -> MagicMock | Console:
     console.get_event.side_effect = events
     console.height = 100
     console.width = 80
+    console.getheightwidth = MagicMock(side_effect=lambda: (console.height, console.width))
+
     for key, val in kwargs.items():
         setattr(console, key, val)
     return console

Lib/test/test_pyrepl/test_reader.py

@@ -228,6 +228,7 @@ def _prepare_console(events):
             console.get_event.side_effect = events
             console.height = 100
             console.width = 80
+            console.getheightwidth = MagicMock(side_effect=lambda: (console.height, console.width))
             console.input_hook = input_hook
             return console
 

Lib/test/test_pyrepl/test_unix_console.py

@@ -250,8 +250,7 @@ def test_resize_bigger_on_multiline_function(self, _os_write):
         events = itertools.chain(code_to_events(code))
         reader, console = handle_events_short_unix_console(events)
 
-        console.height = 2
-        console.getheightwidth = MagicMock(lambda _: (2, 80))
+        console.getheightwidth = MagicMock(side_effect=lambda: (2, 80))
 
         def same_reader(_):
             return reader
@@ -286,8 +285,7 @@ def test_resize_smaller_on_multiline_function(self, _os_write):
         events = itertools.chain(code_to_events(code))
         reader, console = handle_events_unix_console_height_3(events)
 
-        console.height = 1
-        console.getheightwidth = MagicMock(lambda _: (1, 80))
+        console.getheightwidth = MagicMock(side_effect=lambda: (1, 80))
 
         def same_reader(_):
             return reader

Lib/test/test_pyrepl/test_windows_console.py

@@ -129,9 +129,7 @@ def test_resize_wider(self):
         events = code_to_events(code)
         reader, console = self.handle_events_narrow(events)
 
-        console.height = 20
-        console.width = 80
-        console.getheightwidth = MagicMock(lambda _: (20, 80))
+        console.getheightwidth = MagicMock(side_effect=lambda: (20, 80))
 
         def same_reader(_):
             return reader
@@ -157,9 +155,7 @@ def test_resize_narrower(self):
         events = code_to_events(code)
         reader, console = self.handle_events(events)
 
-        console.height = 20
-        console.width = 4
-        console.getheightwidth = MagicMock(lambda _: (20, 4))
+        console.getheightwidth = MagicMock(side_effect=lambda: (20, 4))
 
         def same_reader(_):
             return reader
@@ -292,8 +288,7 @@ def test_resize_bigger_on_multiline_function(self):
         events = itertools.chain(code_to_events(code))
         reader, console = self.handle_events_short(events)
 
-        console.height = 2
-        console.getheightwidth = MagicMock(lambda _: (2, 80))
+        console.getheightwidth = MagicMock(side_effect=lambda: (2, 80))
 
         def same_reader(_):
             return reader
@@ -330,8 +325,7 @@ def test_resize_smaller_on_multiline_function(self):
         events = itertools.chain(code_to_events(code))
         reader, console = self.handle_events_height_3(events)
 
-        console.height = 1
-        console.getheightwidth = MagicMock(lambda _: (1, 80))
+        console.getheightwidth = MagicMock(side_effect=lambda: (1, 80))
 
         def same_reader(_):
             return reader

Misc/NEWS.d/next/Windows/2026-03-27-22-06-10.gh-issue-146458.fYj0UQ.rst

@@ -0,0 +1 @@
+Fix incorrect REPL height and width tracking on console window resize on Windows.