Merge branch 'main' into curses-wide-by-capability

Author: serhiy-storchaka

Doc/library/msvcrt.rst

@@ -135,13 +135,23 @@ Console I/O
 
 .. function:: putch(char)
 
-   Print the byte string *char* to the console without buffering.
+   Print the byte string *char* to the console without buffering.  Raises
+   :exc:`OSError` on failure, for example when the process has no console
+   attached.
+
+   .. versionchanged:: next
+      Failures are now reported by raising :exc:`OSError` instead of being
+      silently ignored.
 
 
 .. function:: putwch(unicode_char)
 
    Wide char variant of :func:`putch`, accepting a Unicode value.
 
+   .. versionchanged:: next
+      Failures are now reported by raising :exc:`OSError` instead of being
+      silently ignored.
+
 
 .. function:: ungetch(char)
 

Lib/test/test_capi/test_mem.py

@@ -24,9 +24,12 @@ def check(self, code):
             out = assert_python_failure(
                 '-c', code,
                 PYTHONMALLOC=self.PYTHONMALLOC,
-                # FreeBSD: instruct jemalloc to not fill freed() memory
-                # with junk byte 0x5a, see JEMALLOC(3)
+                # Instruct the system allocator to not fill freed() memory
+                # with junk bytes:
+                # FreeBSD: jemalloc, see JEMALLOC(3).
                 MALLOC_CONF="junk:false",
+                # OpenBSD: see MALLOC.CONF(5).
+                MALLOC_OPTIONS="j",
             )
         stderr = out.err
         return stderr.decode('ascii', 'replace')
@@ -102,7 +105,9 @@ def check_pyobject_is_freed(self, func_name):
         assert_python_ok(
             '-c', code,
             PYTHONMALLOC=self.PYTHONMALLOC,
+            # See the comment in check() above.
             MALLOC_CONF="junk:false",
+            MALLOC_OPTIONS="j",
         )
 
     def test_pyobject_null_is_freed(self):

Lib/test/test_concurrent_futures/test_init.py

@@ -1,5 +1,6 @@
 import contextlib
 import logging
+import multiprocessing
 import queue
 import time
 import unittest
@@ -147,8 +148,8 @@ def test_spawn(self):
         self._test(ProcessPoolSpawnFailingInitializerTest)
 
     @support.skip_if_sanitizer("TSAN doesn't support threads after fork", thread=True)
-    @unittest.skipIf(sys.platform == "cygwin",
-                     "Forkserver is not available on Cygwin")
+    @unittest.skipUnless("forkserver" in multiprocessing.get_all_start_methods(),
+                         "forkserver start method is not available")
     def test_forkserver(self):
         self._test(ProcessPoolForkserverFailingInitializerTest)
 

Lib/test/test_curses.py

@@ -1997,12 +1997,15 @@ def test_dynamic_color_pairs(self):
         pair = curses.alloc_pair(fg, bg)
         self.assertGreater(pair, 0)
         self.assertEqual(curses.pair_content(pair), (fg, bg))
-        # The same combination of colors reuses the same pair.
-        self.assertEqual(curses.alloc_pair(fg, bg), pair)
-        self.assertEqual(curses.find_pair(fg, bg), pair)
-        # Once freed, the pair is no longer found.
-        self.assertIsNone(curses.free_pair(pair))
-        self.assertEqual(curses.find_pair(fg, bg), -1)
+        if getattr(curses, 'ncurses_version', (6, 3)) >= (6, 3):
+            # The same combination of colors reuses the same pair.
+            self.assertEqual(curses.alloc_pair(fg, bg), pair)
+            self.assertEqual(curses.find_pair(fg, bg), pair)
+            # Once freed, the pair is no longer found.
+            self.assertIsNone(curses.free_pair(pair))
+            self.assertEqual(curses.find_pair(fg, bg), -1)
+        else:
+            self.assertIsNone(curses.free_pair(pair))
 
         # Error paths.
         for color in self.bad_colors2():

Lib/test/test_msvcrt.py

@@ -61,6 +61,19 @@ def test_get_osfhandle(self):
 c_encoded = b'\x57\x5b' # utf-16-le (which windows internally used) encoded char for this CJK char
 
 
+def has_console():
+    # A process created without a console (for example by pythonw.exe, or with
+    # the DETACHED_PROCESS creation flag) cannot write to the console.
+    try:
+        with open('CONOUT$', 'w'):
+            return True
+    except OSError:
+        return False
+
+
+requires_console = unittest.skipUnless(has_console(), 'requires a console')
+
+
 class TestConsoleIO(unittest.TestCase):
     # CREATE_NEW_CONSOLE creates a "popup" window.
     @requires_resource('gui')
@@ -106,12 +119,36 @@ def test_getche(self):
     def test_getwche(self):
         self.check_getwch('getwche')
 
+    @requires_console
     def test_putch(self):
         msvcrt.putch(b'c')
 
+    @requires_console
     def test_putwch(self):
         msvcrt.putwch(c)
 
+    def test_putch_without_console(self):
+        # gh-69573: putch() and putwch() must report the error instead of
+        # silently ignoring it when the process has no console attached.
+        code = dedent('''
+            import msvcrt
+            import sys
+
+            for name, arg in (('putch', b'c'), ('putwch', 'c')):
+                func = getattr(msvcrt, name)
+                try:
+                    func(arg)
+                except OSError:
+                    pass
+                else:
+                    sys.exit(f'msvcrt.{name}() did not raise OSError')
+        ''')
+        # DETACHED_PROCESS: the child process is created without a console.
+        proc = subprocess.run([sys.executable, '-c', code],
+                              creationflags=subprocess.DETACHED_PROCESS,
+                              capture_output=True, text=True)
+        self.assertEqual(proc.returncode, 0, proc.stderr)
+
 
 class TestOther(unittest.TestCase):
     def test_heap_min(self):

Lib/test/test_profiling/test_tracing_profiler.py

@@ -1,4 +1,5 @@
 """Test suite for the cProfile module."""
+import multiprocessing
 import sys
 import unittest
 
@@ -220,8 +221,8 @@ def test_process_spawn_pickle(self):
         # gh-140729: test use Process in cProfile.
         self._test_process_run_pickle('spawn')
 
-    @unittest.skipIf(sys.platform == 'win32',
-                     "No 'forkserver' start method on Windows")
+    @unittest.skipUnless("forkserver" in multiprocessing.get_all_start_methods(),
+                         "forkserver start method is not available")
     def test_process_forkserver_pickle(self):
         # gh-140729: test use Process in cProfile.
         self._test_process_run_pickle('forkserver')

Lib/test/test_pyrepl/test_pyrepl.py

@@ -13,7 +13,7 @@
 import tempfile
 from functools import partial
 from pkgutil import ModuleInfo
-from unittest import TestCase, skipUnless, skipIf, SkipTest
+from unittest import TestCase, skipUnless, SkipTest
 from unittest.mock import Mock, patch
 import warnings
 from test.support import (
@@ -37,6 +37,7 @@
     code_to_events,
 )
 from _colorize import ANSIColors, get_theme
+from _pyrepl import terminfo
 from _pyrepl.console import Event
 from _pyrepl.completing_reader import stripcolor
 from _pyrepl._module_completer import (
@@ -1998,8 +1999,20 @@ def test_dumb_terminal_exits_cleanly(self):
         self.assertNotIn("Traceback", output)
 
 
+def supports_pyrepl():
+    # pyrepl falls back to the basic REPL if the terminal lacks any of the
+    # capabilities which UnixConsole requires.  This covers an unset or
+    # "dumb" TERM as well, they are resolved to the "dumb" capabilities.
+    try:
+        info = terminfo.TermInfo(None)
+    except Exception:
+        return False
+    return all(info.get(cap) is not None
+               for cap in ("bel", "clear", "cup", "el"))
+
+
 @skipUnless(pty, "requires pty")
-@skipIf((os.environ.get("TERM") or "dumb") == "dumb", "can't use pyrepl in dumb terminal")
+@skipUnless(supports_pyrepl(), "can't use pyrepl in this terminal")
 class TestMain(ReplTestCase):
     def setUp(self):
         # Cleanup from PYTHON* variables to isolate from local

Misc/NEWS.d/next/Core_and_Builtins/2026-07-22-14-30-00.gh-issue-154429.Qk9mZ2.rst

@@ -0,0 +1,2 @@
+Slightly speed up deallocation of objects that are not tracked by the garbage
+collector, such as :class:`int`, :class:`float` and :class:`str`.

Misc/NEWS.d/next/Windows/2026-07-21-10-42-18.gh-issue-69573.Kv7QpX.rst

@@ -0,0 +1,4 @@
+:func:`msvcrt.putch` and :func:`msvcrt.putwch` now check the return value of
+the underlying ``_putch()`` and ``_putwch()`` C functions and raise
+:exc:`OSError` on failure, for example when the process has no console
+attached, instead of silently ignoring the error.

Modules/_cursesmodule.c

@@ -763,7 +763,9 @@ curses_getcchar(const cchar_t *wcval, wchar_t *wstr, attr_t *attrs, int *pair)
     /* getcchar() is not guaranteed to write the text of an empty cell, so make
        the output an empty string by default. */
     wstr[0] = L'\0';
-#if _NCURSES_EXTENDED_COLOR_FUNCS
+    /* getcchar()'s opts slot returns the extended color pair, but ncurses
+       returned ERR for a non-NULL opts until 6.3 (patch 20210116). */
+#if _NCURSES_EXTENDED_COLOR_FUNCS && NCURSES_VERSION_PATCH+0 >= 20210116
     int rtn = getcchar(wcval, wstr, attrs, &spair, pair);
 #else
     int rtn = getcchar(wcval, wstr, attrs, &spair, NULL);