[pull] main from python:main

.github/CODEOWNERS

@@ -156,16 +156,15 @@ Misc/libabigail.abignore      @encukou
 # ----------------------------------------------------------------------------
 
 # Android
-Android/                      @mhsmith @freakboy3742
+Platforms/Android/            @mhsmith @freakboy3742
 Doc/using/android.rst         @mhsmith @freakboy3742
 Lib/_android_support.py       @mhsmith @freakboy3742
 Lib/test/test_android.py      @mhsmith @freakboy3742
 
 # iOS
 Doc/using/ios.rst             @freakboy3742
 Lib/_ios_support.py           @freakboy3742
-Apple/                        @freakboy3742
-iOS/                          @freakboy3742
+Platforms/Apple/              @freakboy3742
 
 # macOS
 Mac/                          @python/macos-team
@@ -176,8 +175,8 @@ Lib/test/test__osx_support.py @python/macos-team
 Tools/wasm/README.md          @brettcannon @freakboy3742 @emmatyping
 
 # WebAssembly (Emscripten)
-Tools/wasm/config.site-wasm32-emscripten  @freakboy3742 @emmatyping
-Tools/wasm/emscripten                     @freakboy3742 @emmatyping
+Platforms/emscripten          @freakboy3742 @emmatyping
+Tools/wasm/emscripten         @freakboy3742 @emmatyping
 
 # WebAssembly (WASI)
 Platforms/WASI                @brettcannon @emmatyping @savannahostrowski

Doc/c-api/dict.rst

@@ -151,7 +151,7 @@ Dictionary objects
    * If the key is present, set *\*result* to a new :term:`strong reference`
      to the value and return ``1``.
    * If the key is missing, set *\*result* to ``NULL`` and return ``0``.
-   * On error, raise an exception and return ``-1``.
+   * On error, raise an exception, set *\*result* to ``NULL`` and return ``-1``.
 
    The first argument can be a :class:`dict` or a :class:`frozendict`.
 

Doc/whatsnew/3.15.rst

@@ -411,8 +411,8 @@ embedding applications, and native libraries.
    unwinding for the whole Python process.
 
 (Contributed by Pablo Galindo Salgado and Savannah Ostrowski in
-:gh:`149201`; PEP 831 written by Pablo Galindo Salgado, Ken Jin, and
-Savannah Ostrowski.)
+:gh:`149201`; PEP 831 written by Pablo Galindo Salgado, Ken Jin,
+Savannah Ostrowski, and Diego Russo.)
 
 .. seealso:: :pep:`831` for further details.
 

Include/internal/pycore_bytesobject.h

@@ -62,9 +62,11 @@ _PyBytes_ReverseFind(const char *haystack, Py_ssize_t len_haystack,
 //
 // Export for 'array' shared extension.
 PyAPI_FUNC(void)
-_PyBytes_Repeat(char* dest, Py_ssize_t len_dest,
+_PyBytes_RepeatBuffer(char* dest, Py_ssize_t len_dest,
     const char* src, Py_ssize_t len_src);
 
+PyAPI_FUNC(PyObject *) _PyBytes_Repeat(PyObject *self, Py_ssize_t n);
+
 /* _PyBytesObject_SIZE gives the basic size of a bytes object; any memory allocation
    for a bytes object of length n should request PyBytesObject_SIZE + n bytes.
 

Include/internal/pycore_tuple.h

@@ -29,6 +29,7 @@ PyAPI_FUNC(PyObject *)_PyTuple_FromStackRefStealOnSuccess(const union _PyStackRe
 PyAPI_FUNC(PyObject *)_PyTuple_FromArraySteal(PyObject *const *, Py_ssize_t);
 PyAPI_FUNC(PyObject *) _PyTuple_BinarySlice(PyObject *, PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) _PyTuple_Concat(PyObject *, PyObject *);
+PyAPI_FUNC(PyObject *) _PyTuple_Repeat(PyObject *self, Py_ssize_t n);
 
 PyAPI_FUNC(PyObject *) _PyTuple_FromPair(PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) _PyTuple_FromPairSteal(PyObject *, PyObject *);

Include/internal/pycore_unicodeobject.h

@@ -33,6 +33,7 @@ extern PyObject* _PyUnicode_ResizeCompact(
     Py_ssize_t length);
 extern PyObject* _PyUnicode_GetEmpty(void);
 PyAPI_FUNC(PyObject*) _PyUnicode_BinarySlice(PyObject *, PyObject *, PyObject *);
+PyAPI_FUNC(PyObject *) _PyUnicode_Repeat(PyObject *str, Py_ssize_t len);
 
 
 /* Generic helper macro to convert characters of different types.

Lib/test/test_capi/test_opt.py

@@ -6138,6 +6138,20 @@ def __init__(self, x):
                 C(0) if i else str(0)
         """))
 
+    def test_load_special_type_guard_deopt(self):
+        script_helper.assert_python_ok("-s", "-c", textwrap.dedent(f"""
+            def f1():
+                class Context:
+                    def __enter__(self): ...
+                    def __exit__(self, e, v, t): ...
+
+                with Context():
+                    pass
+
+            for _ in range({TIER2_THRESHOLD + 5}):
+                f1()
+        """), PYTHON_JIT="1")
+
 def global_identity(x):
     return x
 

Misc/NEWS.d/next/Core_and_Builtins/2026-05-07-03-18-59.gh-issue-149459.5fhAqP.rst

@@ -0,0 +1 @@
+Fix a crash in the JIT optimizer when a specialized ``LOAD_SPECIAL`` guard deoptimized after inserting the synthetic ``NULL`` stack entry.

Modules/_remote_debugging/threads.c

@@ -450,12 +450,14 @@ unwind_stack_for_thread(
             set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to collect frames");
             goto error;
         }
-        // Update last_profiled_frame for next sample
-        uintptr_t lpf_addr =
-            *current_tstate + (uintptr_t)unwinder->debug_offsets.thread_state.last_profiled_frame;
-        if (_Py_RemoteDebug_WriteRemoteMemory(&unwinder->handle, lpf_addr,
-                                              sizeof(uintptr_t), &frame_addr) < 0) {
-            PyErr_Clear();  // Non-fatal
+        // Update last_profiled_frame for next sample if it changed
+        if (frame_addr != ctx.last_profiled_frame) {
+            uintptr_t lpf_addr =
+                *current_tstate + (uintptr_t)unwinder->debug_offsets.thread_state.last_profiled_frame;
+            if (_Py_RemoteDebug_WriteRemoteMemory(&unwinder->handle, lpf_addr,
+                                                  sizeof(uintptr_t), &frame_addr) < 0) {
+                PyErr_Clear();  // Non-fatal
+            }
         }
     } else {
         // No caching - process entire frame chain with base_frame validation

Modules/arraymodule.c

@@ -8,7 +8,7 @@
 #endif
 
 #include "Python.h"
-#include "pycore_bytesobject.h"   // _PyBytes_Repeat
+#include "pycore_bytesobject.h"   // _PyBytes_RepeatBuffer
 #include "pycore_call.h"          // _PyObject_CallMethod()
 #include "pycore_ceval.h"         // _PyEval_GetBuiltin()
 #include "pycore_floatobject.h"   // _PY_FLOAT_BIG_ENDIAN
@@ -1147,7 +1147,7 @@ array_repeat(PyObject *op, Py_ssize_t n)
 
     const Py_ssize_t oldbytes = array_length * a->ob_descr->itemsize;
     const Py_ssize_t newbytes = oldbytes * n;
-    _PyBytes_Repeat(np->ob_item, newbytes, a->ob_item, oldbytes);
+    _PyBytes_RepeatBuffer(np->ob_item, newbytes, a->ob_item, oldbytes);
 
     return (PyObject *)np;
 }
@@ -1304,7 +1304,7 @@ array_inplace_repeat(PyObject *op, Py_ssize_t n)
         if (array_resize(self, n * array_size) == -1)
             return NULL;
 
-        _PyBytes_Repeat(self->ob_item, n*size, self->ob_item, size);
+        _PyBytes_RepeatBuffer(self->ob_item, n*size, self->ob_item, size);
     }
     return Py_NewRef(self);
 }

Objects/bytearrayobject.c

@@ -402,7 +402,7 @@ bytearray_repeat_lock_held(PyObject *op, Py_ssize_t count)
     PyByteArrayObject* result = (PyByteArrayObject *)PyByteArray_FromStringAndSize(NULL, size);
     const char* buf = PyByteArray_AS_STRING(self);
     if (result != NULL && size != 0) {
-        _PyBytes_Repeat(result->ob_bytes, size, buf, mysize);
+        _PyBytes_RepeatBuffer(result->ob_bytes, size, buf, mysize);
     }
     return (PyObject *)result;
 }
@@ -439,7 +439,7 @@ bytearray_irepeat_lock_held(PyObject *op, Py_ssize_t count)
     }
 
     char* buf = PyByteArray_AS_STRING(self);
-    _PyBytes_Repeat(buf, size, buf, mysize);
+    _PyBytes_RepeatBuffer(buf, size, buf, mysize);
 
     return Py_NewRef(self);
 }

Objects/bytesobject.c

@@ -3,7 +3,7 @@
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
 #include "pycore_bytes_methods.h" // _Py_bytes_startswith()
-#include "pycore_bytesobject.h"   // _PyBytes_Find(), _PyBytes_Repeat()
+#include "pycore_bytesobject.h"   // _PyBytes_Find(), _PyBytes_RepeatBuffer()
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
 #include "pycore_ceval.h"         // _PyEval_GetBuiltin()
 #include "pycore_format.h"        // F_LJUST
@@ -1581,8 +1581,8 @@ _PyBytes_Concat(PyObject *a, PyObject *b)
     return result;
 }
 
-static PyObject *
-bytes_repeat(PyObject *self, Py_ssize_t n)
+PyObject *
+_PyBytes_Repeat(PyObject *self, Py_ssize_t n)
 {
     PyBytesObject *a = _PyBytes_CAST(self);
     if (n < 0)
@@ -1613,7 +1613,7 @@ bytes_repeat(PyObject *self, Py_ssize_t n)
     set_ob_shash(op, -1);
     op->ob_sval[size] = '\0';
 
-    _PyBytes_Repeat(op->ob_sval, size, a->ob_sval, Py_SIZE(a));
+    _PyBytes_RepeatBuffer(op->ob_sval, size, a->ob_sval, Py_SIZE(a));
 
     return (PyObject *) op;
 }
@@ -1805,7 +1805,7 @@ bytes_buffer_getbuffer(PyObject *op, Py_buffer *view, int flags)
 static PySequenceMethods bytes_as_sequence = {
     bytes_length,       /*sq_length*/
     _PyBytes_Concat,       /*sq_concat*/
-    bytes_repeat,       /*sq_repeat*/
+    _PyBytes_Repeat,    /*sq_repeat*/
     bytes_item,         /*sq_item*/
     0,                  /*sq_slice*/
     0,                  /*sq_ass_item*/
@@ -3555,7 +3555,7 @@ bytes_iter(PyObject *seq)
 
 
 void
-_PyBytes_Repeat(char* dest, Py_ssize_t len_dest,
+_PyBytes_RepeatBuffer(char* dest, Py_ssize_t len_dest,
     const char* src, Py_ssize_t len_src)
 {
     if (len_dest == 0) {

Objects/tupleobject.c

@@ -594,8 +594,8 @@ _PyTuple_Concat(PyObject *aa, PyObject *bb)
     return (PyObject *)np;
 }
 
-static PyObject *
-tuple_repeat(PyObject *self, Py_ssize_t n)
+PyObject *
+_PyTuple_Repeat(PyObject *self, Py_ssize_t n)
 {
     PyTupleObject *a = _PyTuple_CAST(self);
     const Py_ssize_t input_size = Py_SIZE(a);
@@ -865,7 +865,7 @@ tuple_subtype_new(PyTypeObject *type, PyObject *iterable)
 static PySequenceMethods tuple_as_sequence = {
     tuple_length,                               /* sq_length */
     _PyTuple_Concat,                            /* sq_concat */
-    tuple_repeat,                               /* sq_repeat */
+    _PyTuple_Repeat,                            /* sq_repeat */
     tuple_item,                                 /* sq_item */
     0,                                          /* sq_slice */
     0,                                          /* sq_ass_item */

Objects/unicodeobject.c

@@ -41,7 +41,7 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
 #include "pycore_bytes_methods.h" // _Py_bytes_lower()
-#include "pycore_bytesobject.h"   // _PyBytes_Repeat()
+#include "pycore_bytesobject.h"   // _PyBytes_RepeatBuffer()
 #include "pycore_ceval.h"         // _PyEval_GetBuiltin()
 #include "pycore_codecs.h"        // _PyCodec_Lookup()
 #include "pycore_critical_section.h" // Py_*_CRITICAL_SECTION_SEQUENCE_FAST
@@ -12502,8 +12502,8 @@ unicode_rstrip_impl(PyObject *self, PyObject *chars)
 }
 
 
-static PyObject*
-unicode_repeat(PyObject *str, Py_ssize_t len)
+PyObject *
+_PyUnicode_Repeat(PyObject *str, Py_ssize_t len)
 {
     PyObject *u;
     Py_ssize_t nchars, n;
@@ -12548,7 +12548,7 @@ unicode_repeat(PyObject *str, Py_ssize_t len)
     else {
         Py_ssize_t char_size = PyUnicode_KIND(str);
         char *to = (char *) PyUnicode_DATA(u);
-        _PyBytes_Repeat(to, nchars * char_size, PyUnicode_DATA(str),
+        _PyBytes_RepeatBuffer(to, nchars * char_size, PyUnicode_DATA(str),
             PyUnicode_GET_LENGTH(str) * char_size);
     }
 
@@ -13734,7 +13734,7 @@ static PyNumberMethods unicode_as_number = {
 static PySequenceMethods unicode_as_sequence = {
     unicode_length,     /* sq_length */
     PyUnicode_Concat,   /* sq_concat */
-    unicode_repeat,     /* sq_repeat */
+    _PyUnicode_Repeat,  /* sq_repeat */
     unicode_getitem,    /* sq_item */
     0,                  /* sq_slice */
     0,                  /* sq_ass_item */

Python/optimizer_bytecodes.c

@@ -2043,7 +2043,16 @@ dummy_func(void) {
             PyObject *name = _Py_SpecialMethods[oparg].name;
             PyObject *descr = _PyType_Lookup(type, name);
             if (descr != NULL && (Py_TYPE(descr)->tp_flags & Py_TPFLAGS_METHOD_DESCRIPTOR)) {
-                ADD_OP(_GUARD_TYPE_VERSION, 0, type->tp_version_tag);
+                /* LOAD_SPECIAL expands to _RECORD_TOS_TYPE + _INSERT_NULL +
+                 * _LOAD_SPECIAL. Insert _GUARD_TYPE_VERSION before the
+                 * already-emitted _INSERT_NULL so deopt sees the original
+                 * stack shape.*/
+                _PyUOpInstruction *insert_null = uop_buffer_last(&ctx->out_buffer);
+                assert(insert_null->opcode == _INSERT_NULL);
+                assert(insert_null->target == this_instr->target);
+                REPLACE_OP(insert_null, _GUARD_TYPE_VERSION, 0, type->tp_version_tag);
+                ADD_OP(_INSERT_NULL, 0, 0);
+
                 bool immortal = _Py_IsImmortal(descr) || (type->tp_flags & Py_TPFLAGS_IMMUTABLETYPE);
                 ADD_OP(immortal ? _LOAD_CONST_INLINE_BORROW : _LOAD_CONST_INLINE,
                        0, (uintptr_t)descr);