Sync pre-release CPython 3.15 branch from GitHub (2026-05-17)

Summary:
Imported python/cpython `3.15.0b1+` from upstream rev [`42ff9b4`](https://www.github.com/python/cpython/commit/42ff9b4959667cf31bde13a53fca01b1ec381168) (committed 2026-05-17 11:01:15+00:00).

# Commit Info

Base: (`3.15.0b1+`) - [`ec3aa6a`](https://www.github.com/python/cpython/commit/ec3aa6ab4847ebd6f8f3e9b2b7023c5ab3a6e39a) (commit date: 2026-05-16 09:06:14+00:00)
Imported: (`3.15.0b1+`) - [`42ff9b4`](https://www.github.com/python/cpython/commit/42ff9b4959667cf31bde13a53fca01b1ec381168) (commit date: 2026-05-17 11:01:15+00:00)

# Noteworthy file changes

- Low-signal files (1 added) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GCp6CieCjr1S-3MDAER1nbt-InNIbr0LAAAz

Differential Revision: D105521759

fbshipit-source-id: f0b4e91a72baf915c4cdde1f8d37f343cf409965

Author: generatedunixname1734921407115435

Lib/test/test_email/test_email.py

@@ -4995,15 +4995,8 @@ def test_body_encode(self):
         # Try the convert argument, where input codec != output codec
         c = Charset('euc-jp')
         # With apologies to Tokio Kikuchi ;)
-        # XXX FIXME
-##         try:
-##             eq('\x1b$B5FCO;~IW\x1b(B',
-##                c.body_encode('\xb5\xc6\xc3\xcf\xbb\xfe\xc9\xd7'))
-##             eq('\xb5\xc6\xc3\xcf\xbb\xfe\xc9\xd7',
-##                c.body_encode('\xb5\xc6\xc3\xcf\xbb\xfe\xc9\xd7', False))
-##         except LookupError:
-##             # We probably don't have the Japanese codecs installed
-##             pass
+        eq('\x1b$B5FCO;~IW\x1b(B',
+           c.body_encode('\u83ca\u5730\u6642\u592b'))
         # Testing SF bug #625509, which we have to fake, since there are no
         # built-in encodings where the header encoding is QP but the body
         # encoding is not.

Misc/NEWS.d/next/Library/2026-05-16-21-08-33.gh-issue-149921.I1yNML.rst

@@ -0,0 +1,2 @@
+Fix reference leaks in error paths of the :mod:`!_interpchannels` and
+:mod:`!_interpqueues` extension modules.

Modules/_interpchannelsmodule.c

@@ -2586,6 +2586,7 @@ static PyObject *
 _channelid_from_xid(_PyXIData_t *data)
 {
     struct _channelid_xid *xid = (struct _channelid_xid *)_PyXIData_DATA(data);
+    PyObject *cidobj = NULL;
 
     // It might not be imported yet, so we can't use _get_current_module().
     PyObject *mod = PyImport_ImportModule(MODULE_NAME_STR);
@@ -2595,11 +2596,10 @@ _channelid_from_xid(_PyXIData_t *data)
     assert(mod != Py_None);
     module_state *state = get_module_state(mod);
     if (state == NULL) {
-        return NULL;
+        goto done;
     }
 
     // Note that we do not preserve the "resolve" flag.
-    PyObject *cidobj = NULL;
     int err = newchannelid(state->ChannelIDType, xid->cid, xid->end,
                            _global_channels(), 0, 0,
                            (channelid **)&cidobj);

Modules/_interpqueuesmodule.c

@@ -1363,6 +1363,7 @@ _queueobj_from_xid(_PyXIData_t *data)
     if (mod == NULL) {
         mod = PyImport_ImportModule(MODULE_NAME_STR);
         if (mod == NULL) {
+            Py_DECREF(qidobj);
             return NULL;
         }
     }