[pull] main from python:main

InternalDocs/compiler.md

@@ -359,19 +359,19 @@ in [Python/compile.c](../Python/compile.c) into a sequence of pseudo instruction
 These are similar to bytecode, but in some cases they are more abstract, and are
 resolved later into actual bytecode. The construction of this instruction sequence
 is handled by several functions that break the task down by various AST node types.
-The functions are all named `compiler_visit_{xx}` where *xx* is the name of the node
+The functions are all named `codegen_visit_{xx}` where *xx* is the name of the node
 type (such as `stmt`, `expr`, etc.).  Each function receives a `struct compiler *`
 and `{xx}_ty` where *xx* is the AST node type.  Typically these functions
 consist of a large 'switch' statement, branching based on the kind of
 node type passed to it.  Simple things are handled inline in the
 'switch' statement with more complex transformations farmed out to other
-functions named `compiler_{xx}` with *xx* being a descriptive name of what is
+functions named `codegen_{xx}` with *xx* being a descriptive name of what is
 being handled.
 
 When transforming an arbitrary AST node, use the `VISIT()` macro.
-The appropriate `compiler_visit_{xx}` function is called, based on the value
+The appropriate `codegen_visit_{xx}` function is called, based on the value
 passed in for <node type> (so `VISIT({c}, expr, {node})` calls
-`compiler_visit_expr({c}, {node})`).  The `VISIT_SEQ()` macro is very similar,
+`codegen_visit_expr({c}, {node})`).  The `VISIT_SEQ()` macro is very similar,
 but is called on AST node sequences (those values that were created as
 arguments to a node that used the '*' modifier).
 
@@ -414,8 +414,8 @@ which is added at the end of a function is not associated with any
 line in the source code.
 
 There are several helper functions that will emit pseudo-instructions
-and are named `compiler_{xx}()` where *xx* is what the function helps
-with (`list`, `boolop`, etc.).  A rather useful one is `compiler_nameop()`.
+and are named `codegen_{xx}()` where *xx* is what the function helps
+with (`list`, `boolop`, etc.).  A rather useful one is `codegen_nameop()`.
 This function looks up the scope of a variable and, based on the
 expression context, emits the proper opcode to load, store, or delete
 the variable.

Lib/asyncio/base_events.py

@@ -969,7 +969,7 @@ async def _sock_sendfile_native(self, sock, file, offset, count):
             f"and file {file!r} combination")
 
     async def _sock_sendfile_fallback(self, sock, file, offset, count):
-        if offset:
+        if hasattr(file, 'seek'):
             file.seek(offset)
         blocksize = (
             min(count, constants.SENDFILE_FALLBACK_READBUFFER_SIZE)
@@ -1286,7 +1286,6 @@ async def sendfile(self, transport, file, offset=0, count=None,
             raise RuntimeError(
                 f"fallback is disabled and native sendfile is not "
                 f"supported for transport {transport!r}")
-
         return await self._sendfile_fallback(transport, file,
                                              offset, count)
 
@@ -1295,7 +1294,7 @@ async def _sendfile_native(self, transp, file, offset, count):
             "sendfile syscall is not supported")
 
     async def _sendfile_fallback(self, transp, file, offset, count):
-        if offset:
+        if hasattr(file, 'seek'):
             file.seek(offset)
         blocksize = min(count, 16384) if count else 16384
         buf = bytearray(blocksize)

Lib/asyncio/proactor_events.py

@@ -756,8 +756,7 @@ async def _sock_sendfile_native(self, sock, file, offset, count):
                 offset += blocksize
                 total_sent += blocksize
         finally:
-            if total_sent > 0:
-                file.seek(offset)
+            file.seek(offset)
 
     async def _sendfile_native(self, transp, file, offset, count):
         resume_reading = transp.is_reading()

Lib/asyncio/selector_events.py

@@ -53,7 +53,7 @@ def _test_selector_event(selector, fd, event):
 class BaseSelectorEventLoop(base_events.BaseEventLoop):
     """Selector event loop.
 
-    See events.EventLoop for API specification.
+    See events.AbstractEventLoop for API specification.
     """
 
     def __init__(self, selector=None):

Lib/asyncio/unix_events.py

@@ -385,12 +385,12 @@ def _sock_sendfile_native_impl(self, fut, registered_fd, sock, fileno,
             # order to simplify the common case.
             self.remove_writer(registered_fd)
         if fut.cancelled():
-            self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+            self._sock_sendfile_update_filepos(fileno, offset)
             return
         if count:
             blocksize = count - total_sent
             if blocksize <= 0:
-                self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+                self._sock_sendfile_update_filepos(fileno, offset)
                 fut.set_result(total_sent)
                 return
 
@@ -424,20 +424,20 @@ def _sock_sendfile_native_impl(self, fut, registered_fd, sock, fileno,
                 # plain send().
                 err = exceptions.SendfileNotAvailableError(
                     "os.sendfile call failed")
-                self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+                self._sock_sendfile_update_filepos(fileno, offset)
                 fut.set_exception(err)
             else:
-                self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+                self._sock_sendfile_update_filepos(fileno, offset)
                 fut.set_exception(exc)
         except (SystemExit, KeyboardInterrupt):
             raise
         except BaseException as exc:
-            self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+            self._sock_sendfile_update_filepos(fileno, offset)
             fut.set_exception(exc)
         else:
             if sent == 0:
                 # EOF
-                self._sock_sendfile_update_filepos(fileno, offset, total_sent)
+                self._sock_sendfile_update_filepos(fileno, offset)
                 fut.set_result(total_sent)
             else:
                 offset += sent
@@ -448,9 +448,9 @@ def _sock_sendfile_native_impl(self, fut, registered_fd, sock, fileno,
                                 fd, sock, fileno,
                                 offset, count, blocksize, total_sent)
 
-    def _sock_sendfile_update_filepos(self, fileno, offset, total_sent):
-        if total_sent > 0:
-            os.lseek(fileno, offset, os.SEEK_SET)
+    def _sock_sendfile_update_filepos(self, fileno, offset):
+        # After this helper runs, the source fd's lseek pointer is at offset."
+        os.lseek(fileno, offset, os.SEEK_SET)
 
     def _sock_add_cancellation_callback(self, fut, sock):
         def cb(fut):

Lib/asyncio/windows_events.py

@@ -610,6 +610,9 @@ def sendfile(self, sock, file, offset, count):
         ov = _overlapped.Overlapped(NULL)
         offset_low = offset & 0xffff_ffff
         offset_high = (offset >> 32) & 0xffff_ffff
+        # TransmitFile ignores OVERLAPPED.Offset for handles not opened with
+        # FILE_FLAG_OVERLAPPED, so seek the CRT file pointer to match.
+        file.seek(offset)
         ov.TransmitFile(sock.fileno(),
                         msvcrt.get_osfhandle(file.fileno()),
                         offset_low, offset_high,

Lib/test/test_asyncio/test_sendfile.py

@@ -228,6 +228,61 @@ def test_sock_sendfile_zero_size(self):
         self.assertEqual(ret, 0)
         self.assertEqual(self.file.tell(), 0)
 
+    def check_sock_sendfile_offset(self, data, offset, force_fallback=False):
+        sock, proto = self.prepare_socksendfile()
+        with tempfile.TemporaryFile() as f:
+            f.write(data)
+            f.flush()
+            self.assertEqual(f.tell(), len(data))
+
+            if force_fallback:
+                async def _sock_sendfile_fail(sock, file, offset, count):
+                    raise asyncio.exceptions.SendfileNotAvailableError()
+                with support.swap_attr(self.loop, '_sock_sendfile_native', _sock_sendfile_fail):
+                    ret = self.run_loop(self.loop.sock_sendfile(sock, f, offset, None))
+            else:
+                ret = self.run_loop(self.loop.sock_sendfile(sock, f, offset, None))
+
+            self.assertEqual(f.tell(), len(data))
+
+        sock.close()
+        self.run_loop(proto.wait_closed())
+
+        self.assertEqual(ret, len(data) - offset)
+
+
+    def test_sock_sendfile_offset(self):
+        data = b'abcdef'
+        for offset in (0, len(data) // 2, len(data)):
+            for force_fallback in (False, True):
+                with self.subTest(offset=offset, force_fallback=force_fallback):
+                    self.check_sock_sendfile_offset(data, offset, force_fallback)
+
+    def check_sendfile_offset(self, offset, fallback):
+        srv_proto, cli_proto = self.prepare_sendfile()
+        self.file.seek(123)
+        coro = self.loop.sendfile(cli_proto.transport, self.file, offset, fallback=fallback)
+        try:
+            ret = self.run_loop(coro)
+        except asyncio.SendfileNotAvailableError:
+            if fallback:
+                raise
+            cli_proto.transport.close()
+            self.run_loop(srv_proto.done)
+            return
+        cli_proto.transport.close()
+        self.run_loop(srv_proto.done)
+        self.assertEqual(ret, len(self.DATA) - offset)
+        self.assertEqual(srv_proto.nbytes, len(self.DATA) - offset)
+        self.assertEqual(srv_proto.data, self.DATA[offset:])
+        self.assertEqual(self.file.tell(), len(self.DATA))
+
+    def test_sendfile_offset(self):
+        for offset in (0, len(self.DATA) // 2, len(self.DATA)):
+            for fallback in (False, True):
+                with self.subTest(offset=offset, fallback=fallback):
+                    self.check_sendfile_offset(offset, fallback)
+
     def test_sock_sendfile_mix_with_regular_send(self):
         buf = b"mix_regular_send" * (4 * 1024)  # 64 KiB
         sock, proto = self.prepare_socksendfile()

Misc/NEWS.d/next/Core_and_Builtins/2026-05-22-17-09-28.gh-issue-150107.GD72-D.rst

@@ -0,0 +1,3 @@
+:mod:`asyncio`: ``sendfile()`` and ``sock_sendfile()`` event loop methods
+now call ``file.seek(offset)`` if *file* has a ``seek()`` method,
+even if *offset* is ``0`` (default value).

Python/import.c

@@ -2168,6 +2168,7 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
 
     struct _Py_ext_module_loader_result res;
     int rc = _PyImport_RunModInitFunc(p0, info, &res);
+    bool main_error = false;
     if (rc < 0) {
         /* We discard res.def. */
         assert(res.module == NULL);
@@ -2192,7 +2193,8 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
                     // obmalloc, so we create a copy here.
                     filename = _PyUnicode_Copy(info->filename);
                     if (filename == NULL) {
-                        return NULL;
+                        main_error = true;
+                        goto main_finally;
                     }
                 }
                 else {
@@ -2238,6 +2240,7 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
                     main_tstate, info->path, info->name, def, &singlephase);
             if (cached == NULL) {
                 assert(PyErr_Occurred());
+                main_error = true;
                 goto main_finally;
             }
         }
@@ -2253,7 +2256,7 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
         // gh-144601: The exception object can't be transferred across
         // interpreters. Instead, we print out an unraisable exception, and
         // then raise a different exception for the calling interpreter.
-        if (rc < 0) {
+        if (rc < 0 || main_error) {
             assert(PyErr_Occurred());
             PyErr_FormatUnraisable("Exception while importing from subinterpreter");
         }
@@ -2262,7 +2265,7 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
         /* Any module we got from the init function will have to be
          * reloaded in the subinterpreter. */
         mod = NULL;
-        if (rc < 0) {
+        if (rc < 0 || main_error) {
             PyErr_SetString(PyExc_ImportError,
                             "failed to import from subinterpreter due to exception");
             goto error;
@@ -2277,6 +2280,9 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
     if (rc < 0) {
         goto error;
     }
+    if (main_error) {
+        goto error;
+    }
 
     if (res.kind == _Py_ext_module_kind_MULTIPHASE) {
         assert_multiphase_def(def);

Python/symtable.c

@@ -1708,7 +1708,7 @@ symtable_enter_type_param_block(struct symtable *st, identifier name,
     return 1;
 }
 
-/* VISIT, VISIT_SEQ and VIST_SEQ_TAIL take an ASDL type as their second argument.
+/* VISIT, VISIT_SEQ and VISIT_SEQ_TAIL take an ASDL type as their second argument.
    They use the ASDL name to synthesize the name of the C type and the visit
    function.