[pull] main from python:main

Lib/tarfile.py

@@ -1601,6 +1601,14 @@ def _proc_pax(self, tarfile):
         # Fetch the next header.
         try:
             next = self._fromtarfile(tarfile, dircheck=False)
+        except EOFHeaderError:
+            if self.type == XGLTYPE:
+                # If this is a global header at the end of the archive
+                # (no regular members follow), let the EOFHeaderError
+                # propagate so the caller handles end-of-archive normally.
+                tarfile.offset = tarfile.fileobj.tell() - BLOCKSIZE
+                raise
+            raise SubsequentHeaderError("end of file header") from None
         except HeaderError as e:
             raise SubsequentHeaderError(str(e)) from None
 

Lib/test/test_builtin.py

@@ -542,6 +542,10 @@ async def sleep(delay, result=None):
             '''a = [x async for x in (x async for x in arange(5))][1]''',
             '''a, = [1 for x in {x async for x in arange(1)}]''',
             '''a = [await sleep(0, x) async for x in arange(2)][1]''',
+            '''a = [await sleep(0, 1) for _ in [0]][0]''',
+            '''a = {await sleep(0, 1) for _ in [0]}.pop()''',
+            '''a = {0: await sleep(0, 1) for _ in [0]}[0]''',
+            '''a = (lambda x=[await sleep(0, 1) for _ in [0]]: x)()[0]''',
             # gh-121637: Make sure we correctly handle the case where the
             # async code is optimized away
             '''assert not await sleep(0); a = 1''',
@@ -610,7 +614,26 @@ async def __aexit__(self, *exc_info):
             '''def f():
                    async with Lock() as l:
                        a = 1
-            '''
+            ''',
+            '''class C:
+                   [await x for x in y]
+            ''',
+            '''class C:
+                   [x async for x in arange(10)]
+            ''',
+            '''async def f():
+                   class C:
+                       [await x for x in y]
+            ''',
+            '''lambda: [await x for x in y]''',
+            '''class C:
+                   def f(self, x=[await y for y in z]):
+                       pass
+            ''',
+            '''type T = [await x for x in y]''',
+            '''async def f[T=[await x for x in y]]():
+                   pass
+            ''',
         ]
         for mode, code_sample in product(modes, code_samples):
             source = dedent(code_sample)

Lib/test/test_coroutines.py

@@ -1,3 +1,4 @@
+import ast
 import contextlib
 import copy
 import inspect
@@ -407,6 +408,118 @@ async def bar():
             with self.subTest(code=code), self.assertRaises(SyntaxError):
                 compile(code, "<test>", "exec")
 
+    def test_async_comprehension_scope(self):
+        # List/set/dict comprehensions with await or async for are allowed
+        # only in async functions, or at module level with top-level await.
+        allowed = [
+            "async def f():\n    [await x for x in y]",
+            "async def f():\n    {await x for x in y}",
+            "async def f():\n    {k: await x for k, x in y}",
+            "async def f():\n    [x async for x in y]",
+            "async def f():\n    {x async for x in y}",
+            "async def f():\n    {k: x async for k, x in y}",
+            "async def f():\n    [[await x for x in y] for y in z]",
+            # Defaults, bases, and genexp iterables are evaluated in the
+            # enclosing scope.
+            "async def outer():\n    async def f(x=[await y for y in z]): pass",
+            "async def f():\n    class C([await x for x in y]): pass",
+            "async def f():\n    (x for x in [await y for y in z])",
+            "async def f():\n    (x for x in [y async for y in z])",
+        ]
+        for code in allowed:
+            with self.subTest(code=code):
+                compile(code, "<test>", "exec")
+
+        # Generator expressions with await are async genexps and may appear
+        # outside async functions. A listcomp nested in a genexp body is also
+        # allowed (the genexp becomes an async generator).
+        for code in [
+            "(await x for x in y)",
+            "def f():\n    (await x for x in y)",
+            "class C:\n    (await x for x in y)",
+            "lambda: (await x for x in y)",
+            "([await x for x in y] for y in z)",
+            "def f():\n    ([await x for x in y] for y in z)",
+            "class C:\n    ([await x for x in y] for y in z)",
+            "async def f():\n    ([await x for x in y] for y in z)",
+        ]:
+            with self.subTest(code=code):
+                compile(code, "<test>", "exec")
+
+        err = "asynchronous comprehension outside of an asynchronous function"
+        invalid = [
+            "[await x for x in y]",
+            "{await x for x in y}",
+            "{k: await x for k, x in y}",
+            "[x async for x in y]",
+            "{x async for x in y}",
+            "{k: x async for k, x in y}",
+            "[[await x for x in y] for y in z]",
+            "[[x async for x in y] for y in z]",
+            "def f():\n    [await x for x in y]",
+            "def f():\n    [x async for x in y]",
+            "async def f():\n    def g():\n        [await x for x in y]",
+            "class C:\n    [await x for x in y]",
+            "class C:\n    {await x for x in y}",
+            "class C:\n    {k: await x for k, x in y}",
+            "class C:\n    [x async for x in y]",
+            "class C:\n    [[await x for x in y] for y in z]",
+            "async def f():\n    class C:\n        x = [await y for y in z]",
+            "async def f():\n    class C:\n        x = [y async for y in z]",
+            # Lambdas are never async, even inside async def.
+            "lambda: [await x for x in y]",
+            "async def f():\n    lambda: [await x for x in y]",
+            "class C:\n    f = lambda: [await x for x in y]",
+            # Defaults, bases, and genexp iterables run in the enclosing scope.
+            "(x for x in [await y for y in z])",
+            "(x for x in [y async for y in z])",
+            "def f():\n    (x for x in [await y for y in z])",
+            "async def f(x=[await y for y in z]): pass",
+            "def f(x=[await y for y in z]): pass",
+            "class C:\n    def f(self, x=[await y for y in z]): pass",
+            "class C([await x for x in y]): pass",
+            # Type aliases and type-parameter scopes.
+            "type T = [await x for x in y]",
+            "type T = [x async for x in y]",
+            "def f[T=[await x for x in y]](): pass",
+            "def f[T: [await x for x in y]](): pass",
+            "async def f[T=[await x for x in y]](): pass",
+            "async def f(x: [await y for y in z]): pass",
+        ]
+        for code in invalid:
+            with self.subTest(code=code):
+                support.check_syntax_error(self, code, err)
+
+        support.check_syntax_error(
+            self, "await x", "'await' outside function")
+        support.check_syntax_error(
+            self, "class C:\n    await x", "'await' outside function")
+        support.check_syntax_error(
+            self, "def f():\n    await x", "'await' outside async function")
+
+        flags = ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
+        for code in [
+            "[await x for x in y]",
+            "async def f(x=[await y for y in z]): pass",
+            "class C([await x for x in y]): pass",
+            "f'{[await x for x in y]}'",
+            "(x for x in [await y for y in z])",
+            "(x for x in [y async for y in z])",
+        ]:
+            with self.subTest(code=code, tla=True):
+                compile(code, "<test>", "exec", flags=flags)
+        still_invalid = [
+            "lambda: [await x for x in y]",
+            "def f():\n    (x for x in [await y for y in z])",
+            "class C:\n    def f(self, x=[await y for y in z]): pass",
+            "type T = [await x for x in y]",
+            "async def f[T=[await x for x in y]](): pass",
+        ]
+        for code in still_invalid:
+            with self.subTest(code=code, tla=True):
+                with self.assertRaisesRegex(SyntaxError, err):
+                    compile(code, "<test>", "exec", flags=flags)
+
     def test_badsyntax_2(self):
         samples = [
             """def foo():

Lib/test/test_tarfile.py

@@ -2499,6 +2499,35 @@ def test_pax_global_header(self):
         finally:
             tar.close()
 
+    def test_pax_global_header_empty_archive(self):
+        # An archive that contains only a global header and no regular
+        # members should be opened successfully (gh-149578).
+        pax_headers = {"foo": "bar"}
+
+        # Create a PAX archive with global headers but no file entries.
+        with tarfile.open(tmpname, "w", format=tarfile.PAX_FORMAT,
+                          pax_headers=pax_headers):
+            pass
+
+        # Reading the archive should work and preserve global headers.
+        with tarfile.open(tmpname) as tar:
+            self.assertEqual(tar.pax_headers, pax_headers)
+            self.assertEqual(tar.getmembers(), [])
+
+        # Appending to the archive should work.
+        with tarfile.open(tmpname, "a") as tar:
+            self.assertEqual(tar.pax_headers, pax_headers)
+            self.assertEqual(tar.getmembers(), [])
+            tar.addfile(tarfile.TarInfo("test"))
+
+        # Verify the appended member is present and global headers
+        # are preserved.
+        with tarfile.open(tmpname) as tar:
+            self.assertEqual(tar.pax_headers, pax_headers)
+            members = tar.getmembers()
+            self.assertEqual(len(members), 1)
+            self.assertEqual(members[0].name, "test")
+
     def test_pax_extended_header(self):
         # The fields from the pax header have priority over the
         # TarInfo.

Misc/NEWS.d/next/Library/2026-05-10-12-00-00.gh-issue-149578.5cgq7iV.rst

@@ -0,0 +1,3 @@
+Fix :func:`tarfile.open` failing with :exc:`~tarfile.ReadError` when
+opening a PAX format tar archive that contains only global headers and
+no regular members.