Merge branch 'main' into fix-issue-139686

Author: brettcannon

Doc/library/xmlrpc.client.rst

@@ -472,7 +472,7 @@ remote server into a single request [#]_.
 
    Create an object used to boxcar method calls. *server* is the eventual target of
    the call. Calls can be made to the result object, but they will immediately
-   return ``None``, and only store the call name and parameters in the
+   return ``None``, and only store the call name and arguments in the
    :class:`MultiCall` object. Calling the object itself causes all stored calls to
    be transmitted as a single ``system.multicall`` request. The result of this call
    is a :term:`generator`; iterating over this generator yields the individual

Include/cpython/object.h

@@ -436,8 +436,6 @@ PyAPI_FUNC(void) _Py_NO_RETURN _PyObject_AssertFailed(
 PyAPI_FUNC(void) _PyTrash_thread_deposit_object(PyThreadState *tstate, PyObject *op);
 PyAPI_FUNC(void) _PyTrash_thread_destroy_chain(PyThreadState *tstate);
 
-PyAPI_FUNC(int) _Py_ReachedRecursionLimitWithMargin(PyThreadState *tstate, int margin_count);
-
 /* For backwards compatibility with the old trashcan mechanism */
 #define Py_TRASHCAN_BEGIN(op, dealloc)
 #define Py_TRASHCAN_END

Include/internal/pycore_ceval.h

@@ -263,6 +263,11 @@ static inline int _Py_ReachedRecursionLimit(PyThreadState *tstate)  {
 #endif
 }
 
+// Export for test_peg_generator
+PyAPI_FUNC(int) _Py_ReachedRecursionLimitWithMargin(
+    PyThreadState *tstate,
+    int margin_count);
+
 static inline void _Py_LeaveRecursiveCall(void)  {
 }
 

Include/internal/pycore_pymem.h

@@ -70,6 +70,27 @@ static inline int _PyMem_IsPtrFreed(const void *ptr)
 #endif
 }
 
+// Similar to _PyMem_IsPtrFreed() but expects an 'unsigned long' instead of a
+// pointer.
+static inline int _PyMem_IsULongFreed(unsigned long value)
+{
+#if SIZEOF_LONG == 8
+    return (value == 0
+            || value == (unsigned long)0xCDCDCDCDCDCDCDCD
+            || value == (unsigned long)0xDDDDDDDDDDDDDDDD
+            || value == (unsigned long)0xFDFDFDFDFDFDFDFD
+            || value == (unsigned long)0xFFFFFFFFFFFFFFFF);
+#elif SIZEOF_LONG == 4
+    return (value == 0
+            || value == (unsigned long)0xCDCDCDCD
+            || value == (unsigned long)0xDDDDDDDD
+            || value == (unsigned long)0xFDFDFDFD
+            || value == (unsigned long)0xFFFFFFFF);
+#else
+#  error "unknown long size"
+#endif
+}
+
 extern int _PyMem_GetAllocatorName(
     const char *name,
     PyMemAllocatorName *allocator);

Include/internal/pycore_tracemalloc.h

@@ -30,8 +30,8 @@ struct _PyTraceMalloc_Config {
 };
 
 
-/* Pack the frame_t structure to reduce the memory footprint on 64-bit
-   architectures: 12 bytes instead of 16. */
+/* Pack the tracemalloc_frame and tracemalloc_traceback structures to reduce
+   the memory footprint on 64-bit architectures: 12 bytes instead of 16. */
 #if defined(_MSC_VER)
 #pragma pack(push, 4)
 #endif
@@ -46,18 +46,22 @@ tracemalloc_frame {
     PyObject *filename;
     unsigned int lineno;
 };
-#ifdef _MSC_VER
-#pragma pack(pop)
-#endif
 
-struct tracemalloc_traceback {
+struct
+#ifdef __GNUC__
+__attribute__((packed))
+#endif
+tracemalloc_traceback {
     Py_uhash_t hash;
     /* Number of frames stored */
     uint16_t nframe;
     /* Total number of frames the traceback had */
     uint16_t total_nframe;
-    struct tracemalloc_frame frames[1];
+    struct tracemalloc_frame frames[];
 };
+#ifdef _MSC_VER
+#pragma pack(pop)
+#endif
 
 
 struct _tracemalloc_runtime_state {
@@ -95,7 +99,7 @@ struct _tracemalloc_runtime_state {
        Protected by TABLES_LOCK(). */
     _Py_hashtable_t *domains;
 
-    struct tracemalloc_traceback empty_traceback;
+    struct tracemalloc_traceback *empty_traceback;
 
     Py_tss_t reentrant_key;
 };

Lib/importlib/_bootstrap_external.py

@@ -208,12 +208,8 @@ def _write_atomic(path, data, mode=0o666):
     try:
         # We first write data to a temporary file, and then use os.replace() to
         # perform an atomic rename.
-        with _io.FileIO(fd, 'wb') as file:
-            bytes_written = file.write(data)
-        if bytes_written != len(data):
-            # Raise an OSError so the 'except' below cleans up the partially
-            # written file.
-            raise OSError("os.write() didn't write the full pyc file")
+        with _io.open(fd, 'wb') as file:
+            file.write(data)
         _os.replace(path_tmp, path)
     except OSError:
         try:

Lib/test/test_importlib/test_util.py

@@ -788,31 +788,70 @@ def test_complete_multi_phase_init_module(self):
             self.run_with_own_gil(script)
 
 
-class MiscTests(unittest.TestCase):
-    def test_atomic_write_should_notice_incomplete_writes(self):
+class PatchAtomicWrites:
+    def __init__(self, truncate_at_length, never_complete=False):
+        self.truncate_at_length = truncate_at_length
+        self.never_complete = never_complete
+        self.seen_write = False
+        self._children = []
+
+    def __enter__(self):
         import _pyio
 
         oldwrite = os.write
-        seen_write = False
-
-        truncate_at_length = 100
 
         # Emulate an os.write that only writes partial data.
         def write(fd, data):
-            nonlocal seen_write
-            seen_write = True
-            return oldwrite(fd, data[:truncate_at_length])
+            if self.seen_write and self.never_complete:
+                return None
+            self.seen_write = True
+            return oldwrite(fd, data[:self.truncate_at_length])
 
         # Need to patch _io to be _pyio, so that io.FileIO is affected by the
         # os.write patch.
-        with (support.swap_attr(_bootstrap_external, '_io', _pyio),
-              support.swap_attr(os, 'write', write)):
-            with self.assertRaises(OSError):
-                # Make sure we write something longer than the point where we
-                # truncate.
-                content = b'x' * (truncate_at_length * 2)
-                _bootstrap_external._write_atomic(os_helper.TESTFN, content)
-        assert seen_write
+        self.children = [
+            support.swap_attr(_bootstrap_external, '_io', _pyio),
+            support.swap_attr(os, 'write', write)
+        ]
+        for child in self.children:
+            child.__enter__()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        for child in self.children:
+            child.__exit__(exc_type, exc_val, exc_tb)
+
+
+class MiscTests(unittest.TestCase):
+
+    def test_atomic_write_retries_incomplete_writes(self):
+        truncate_at_length = 100
+        length = truncate_at_length * 2
+
+        with PatchAtomicWrites(truncate_at_length=truncate_at_length) as cm:
+            # Make sure we write something longer than the point where we
+            # truncate.
+            content = b'x' * length
+            _bootstrap_external._write_atomic(os_helper.TESTFN, content)
+        self.assertTrue(cm.seen_write)
+
+        self.assertEqual(os.stat(support.os_helper.TESTFN).st_size, length)
+        os.unlink(support.os_helper.TESTFN)
+
+    def test_atomic_write_errors_if_unable_to_complete(self):
+        truncate_at_length = 100
+
+        with (
+            PatchAtomicWrites(
+                truncate_at_length=truncate_at_length, never_complete=True,
+            ) as cm,
+            self.assertRaises(OSError)
+        ):
+            # Make sure we write something longer than the point where we
+            # truncate.
+            content = b'x' * (truncate_at_length * 2)
+            _bootstrap_external._write_atomic(os_helper.TESTFN, content)
+        self.assertTrue(cm.seen_write)
 
         with self.assertRaises(OSError):
             os.stat(support.os_helper.TESTFN) # Check that the file did not get written.

Lib/test/test_sysconfig.py

@@ -20,7 +20,7 @@
 )
 from test.support.import_helper import import_module
 from test.support.os_helper import (TESTFN, unlink, skip_unless_symlink,
-                                    change_cwd)
+                                    change_cwd, EnvironmentVarGuard)
 from test.support.venv import VirtualEnvironmentMixin
 
 import sysconfig
@@ -807,7 +807,9 @@ def test_parse_makefile_renamed_vars(self):
             print("PY_LDFLAGS=-lm", file=makefile)
             print("var2=$(LDFLAGS)", file=makefile)
             print("var3=$(CPPFLAGS)", file=makefile)
-        vars = _parse_makefile(TESTFN)
+        with EnvironmentVarGuard() as env:
+            env.clear()
+            vars = _parse_makefile(TESTFN)
         self.assertEqual(vars, {
             'var1': '-Wall',
             'CFLAGS': '-Wall',

Misc/NEWS.d/next/Core_and_Builtins/2025-11-24-21-09-30.gh-issue-141930.hIIzSd.rst

@@ -0,0 +1,2 @@
+When importing a module, use Python's regular file object to ensure that
+writes to ``.pyc`` files are complete or an appropriate error is raised.

Misc/NEWS.d/next/Tests/2025-10-16-15-08-58.gh-issue-140210.P9vUP8.rst

@@ -0,0 +1,2 @@
+Make ``test_sysconfig.test_parse_makefile_renamed_vars`` less fragile by
+clearing the environment variables before parsing the Makefile.