gh-115634: Fix ProcessPoolExecutor deadlock with max_tasks_per_child (GH-140900)
The idle worker semaphore counts task completions, not idle workers, so
it can hold a stale token released by a worker that later exited upon
reaching its max_tasks_per_child limit. The worker replacement path
consumed such tokens and skipped spawning a replacement, deadlocking
the remaining queued tasks once no workers were left.
Replace dead workers based on len(self._processes) without consulting
the semaphore. The submit() path is unchanged, preserving on-demand
spawning and idle worker reuse.
Replace the documentation note added in GH-140897 with a versionchanged
entry now that the bug is fixed.
gh-144067: Document terminal leak when initscr() follows setupterm() (GH-152624)
The curses library keeps a single current terminal: calling initscr()
or newterm() after setupterm() abandons the terminal that setupterm()
allocated without freeing it. This cannot be fixed safely in code
(freeing the terminal would break the capsule API and pending terminfo
queries), so document the behavior, with a cross-reference from
initscr() and newterm().
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
gh-152789: Skip curses tests needing newterm() on ncurses before 6.5 (GH-152880)
ncurses before 6.5 can crash on repeated newterm(). Fall back to initscr()
in TestCurses and skip ScreenTests and SLKTests, which need several screens.
The shared initscr() screen also needs its rendition and background reset
between tests.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Victor Stinner [Thu, 2 Jul 2026 13:00:51 +0000 (15:00 +0200)]
gh-152680: Detect virtualization on Windows in pythoninfo (#152824)
Use WMI to detect virtualization on Windows.
Replace wmic command with _wmi module to get the operating system caption and
version.
The wmic tool is deprecated since January 2024:
https://techcommunity.microsoft.com/blog/windows-itpro-blog/wmi-command-line-wmic-utility-deprecation-next-steps/4039242
For example, it's no longer installed in Windows images on GitHub
Action.
Fix also run_command(): no longer try to spawn a subprocess if the
platform doesn't support subprocess. It avoids logging run_command()
errors.
gh-88574: Skip a spurious blank line after a literal in imaplib (GH-152751)
Some IMAP servers send an extra blank line after the data of a literal.
imaplib mistook it for the response trailer and failed on the next
command. Such a blank line is now skipped.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
gh-66335: Add tests for imaplib command methods (GH-152872)
Add coverage tests for the IMAP4 command methods and their UID variants
(SELECT, CREATE, COPY, STORE, FETCH, SEARCH, SORT, THREAD, DELETE,
RENAME, SUBSCRIBE, UNSUBSCRIBE, LIST, STATUS, the ACL and quota
commands, ANNOTATION, PROXYAUTH and ENABLE), plus test helpers
(splitargs, parse_sequence_set, make_simple_handler) and per-command
argument capture in the test server.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
gh-108280: Give a meaningful error for an invalid imaplib greeting (GH-152768)
Connecting to a server that does not send a valid IMAP4 greeting, such as
a POP3 server answering on the IMAP port, failed with the unhelpful
"imaplib.IMAP4.error: None". A meaningful message is now raised instead.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
gh-63121: Refresh imaplib capabilities on state changes (GH-152752)
imaplib fetched the server capabilities only once, at connection time.
They are now also refreshed after a successful LOGIN or AUTHENTICATE,
from the CAPABILITY response the server sent or, if it sent none, by
querying it. This lets methods such as enable() see capabilities added
after login, for example ENABLE on Gmail (gh-103451).
Capabilities advertised in the server greeting are now used too, saving
a redundant CAPABILITY command.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
gh-82183: Do not restart the busy IDLE shell when running without restart (#152745)
"Run... Customized" with "Restart shell" unchecked restarted the shell
anyway when it was busy executing code, killing any pending input. It now
reports that the shell is executing just once, not twice, and does not run.
gh-134300: Remove idlelib from the path of the IDLE user process (#152739)
The idlelib directory ends up on sys.path when idle.py is run as a script,
and it was passed to the user process, where it let user code import
idlelib submodules as top-level modules, such as "import help".
gh-71956: Fix IDLE Replace All searching up without wrap around (#152737)
When the search direction is "Up" and "Wrap around" is off, Replace All
replaced only the first match above the current position (and all matches
below it). It now replaces all matches from the start of the text down to
the current position, consistently with the "Up" direction.
gh-66331: Set correct WM_CLASS on X11 for IDLE windows (#152733)
Set the WM_CLASS of IDLE's long-lived windows (window-list windows and
the stack viewers) to "Idle" instead of the default "Toplevel", so that
window managers group and label them correctly.
Bump the `actions/{github-script,checkout}` and `j178/prek-action` actions (#152760)
Bumps the actions group with 3 updates: [actions/github-script](https://github.com/actions/github-script), [actions/checkout](https://github.com/actions/checkout) and [j178/prek-action](https://github.com/j178/prek-action).
Serhiy Storchaka [Tue, 30 Jun 2026 19:24:07 +0000 (22:24 +0300)]
gh-152502: Detect the curses mouse interface and is_* methods portably (GH-152705)
The mouse interface (getmouse(), has_mouse(), the BUTTON* constants,
window.mouse_trafo(), ...) and the window is_*() state-query methods were gated
on ncurses-specific macros, so they were dropped on other curses implementations
that provide them, such as NetBSD curses and PDCurses.
Gate them instead on configure capability probes (for functions NetBSD curses
provides, since it defines no identifying macro) or on NCURSES_EXT_FUNCS or the
PDCURSES macro (for functions only ncurses and PDCurses provide). Probe for
getmouse() with its X/Open getmouse(MEVENT *) signature, since PDCurses declares
an incompatible getmouse(void) unless built for the ncurses mouse API, which
PDC_NCMOUSE now always selects.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Petr Vaganov [Tue, 30 Jun 2026 14:45:25 +0000 (21:45 +0700)]
gh-152682: Fix NULL dereference on OOM in `symtable_visit_type_param_bound_or_default` (#152684)
In `symtable_visit_type_param_bound_or_default()`, when a reserved name
(e.g. `__classdict__`) is used as a type parameter, `PyUnicode_FromFormat()`
is called to build the SyntaxError message. If the allocation fails and
returns NULL, the subsequent `PyErr_SetObject()` and `Py_DECREF()` calls
would dereference NULL, causing a segfault.
Fix by returning 0 immediately when `PyUnicode_FromFormat()` returns NULL.
This propagates the MemoryError set by `PyUnicode_FromFormat()`.
The bug was introduced in gh-128632 (commit 891c61c).
Steve Stagg [Tue, 30 Jun 2026 10:57:28 +0000 (11:57 +0100)]
gh-152635: Raise MemoryError when the lock allocation fails in `_interpchannels.create()` (#152642)
Previously, an allocation failure when creating
the lock for a channel in `_interpchannels` would trigger an assert.
Caused by `handle_channel_error` being passed an error code of -1
which is only allowed if an exception has been set.
(in this case, no exception was set)
`channelsmod_create` now forwards the error code from `channel_create`
which `handle_channel_error` already handled.
Serhiy Storchaka [Tue, 30 Jun 2026 09:19:43 +0000 (12:19 +0300)]
gh-50966: Fix unbounded recursion in turtle drag handlers (GH-152626)
TurtleScreenBase._update() redraws with cv.update(), which also reprocesses
input events, so a handler that moves the turtle (such as
screen.ondrag(turtle.goto)) reenters _update() for every queued event until
the interpreter crashes. A reentrant _update() now only flushes drawing with
update_idletasks().
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Tue, 30 Jun 2026 09:09:09 +0000 (12:09 +0300)]
gh-152325: Gate curses.has_mouse() on the ncurses patch level (GH-152652)
has_mouse() was added to ncurses after the 5.7 release, but the binding
guarded it only with NCURSES_MOUSE_VERSION, which 5.7 already defines, so
the module failed to compile against ncurses 5.7 (such as the system
curses on macOS). Gate it additionally on NCURSES_EXT_FUNCS, which holds
the library's patch date.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
xzkdeng [Tue, 30 Jun 2026 09:08:39 +0000 (17:08 +0800)]
gh-133510: Add links to more info for the match statement in FAQ anwser (#133511)
Co-authored-by: sobolevn <mail@sobolevn.me> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com> Co-authored-by: Stan Ulbrych <stan@python.org>
Gregory P. Smith [Tue, 30 Jun 2026 00:05:02 +0000 (17:05 -0700)]
gh-146219: Document reusing a thread state across repeated foreign-thread calls (GH-146221)
* Document reusing a thread state across repeated foreign-thread calls
Add a subsection under "Non-Python created threads" explaining the
performance cost of creating/destroying a PyThreadState on every
Ensure/Release cycle and showing how to keep one alive for the
thread's lifetime instead.
* add a comma
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
---------
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Serhiy Storchaka [Mon, 29 Jun 2026 20:49:19 +0000 (23:49 +0300)]
gh-103878: Return a consistent empty value from cancelled file dialogs (GH-152435)
On cancellation Tcl may report the empty result as '', () or b'' depending
on the platform and Tk version. Normalize it so that askopenfilename(),
asksaveasfilename() and askdirectory() always return '' and
askopenfilenames() always returns ().
Open._fixresult() now distinguishes single from multiple results by the
'multiple' option rather than the result type.
Co-authored-by: Christopher Chavez <chrischavez@gmx.us> Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Mon, 29 Jun 2026 15:30:23 +0000 (18:30 +0300)]
gh-69134: Wait until mapped in keyboard virtual-event tests (GH-152599)
test_virtual_events and test_selection_event generate key events after
focus_force(). On Windows these are only delivered once the toplevel is
mapped, so they could be dropped and the test fail. Wait until the
widget is mapped, as the other GUI tests already do.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Mon, 29 Jun 2026 14:11:03 +0000 (17:11 +0300)]
gh-152587: Make name and value required in tkinter variable methods (GH-152595)
The name parameter of Misc.wait_variable(), setvar() and getvar() and the
value parameter of setvar() no longer have default values, which were not
meaningful ('PY_VAR' and '1').
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
The name parameter of Misc.wait_variable(), setvar() and getvar() and the
value parameter of setvar() should not be optional. Their default values
('PY_VAR' and '1') are not meaningful and should not be advertised.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Mon, 29 Jun 2026 13:15:02 +0000 (16:15 +0300)]
gh-152584: Reorganize the curses documentation into topic subsections (GH-152583)
Reorganize the curses documentation into topic subsections
Group the module-level functions, window methods and constants by topic
instead of presenting them as flat alphabetical lists, following the
categories used by the ncurses manual pages.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Mon, 29 Jun 2026 12:06:47 +0000 (15:06 +0300)]
gh-152503: Fix garbage text from curses wide-character cell reads (GH-152505)
window.in_wch(), window.in_wchstr() and window.getbkgrnd() read a cell
into an uninitialized cchar_t, relying on the curses library to leave the
text NUL-terminated -- which ncurses does but X/Open does not require, so
some libraries (such as NetBSD curses) returned uninitialized bytes as
wide characters. Zero-initialize the cell buffers before the read and
default the getcchar() output to an empty string.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Serhiy Storchaka [Mon, 29 Jun 2026 12:02:12 +0000 (15:02 +0300)]
gh-152502: Detect optional curses functions with configure probes (GH-152504)
Some curses functions were called unconditionally or gated only by the
ncurses-specific NCURSES_EXT_FUNCS macro, which broke building the module
against other curses implementations (narrow ncurses, NetBSD curses) even
when they provided the function. Detect each with a configure capability
probe and gate on HAVE_CURSES_*.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
projects / thirdparty / Python / cpython.git / log
