Merge branch 'fix-proactor-error-hang' into fix-proactor-close-flush

# Conflicts:
#	Lib/asyncio/proactor_events.py

Author: graingert

Doc/library/argparse.rst

@@ -835,7 +835,9 @@ how the command-line arguments should be handled. The supplied actions are:
     >>> parser.parse_args(['-vvv'])
     Namespace(verbose=3)
 
-  Note, the *default* will be ``None`` unless explicitly set to *0*.
+  Unless explicitly set, the *default* will be ``None``. If the default
+  value is a non-zero number, the count starts from that number rather
+  than from zero.
 
 * ``'help'`` - This prints a complete help message for all the options in the
   current parser and then exits. By default a help action is automatically

Include/internal/pycore_compile.h

@@ -110,6 +110,7 @@ enum _PyCompile_FBlockType {
      COMPILE_FBLOCK_EXCEPTION_HANDLER,
      COMPILE_FBLOCK_EXCEPTION_GROUP_HANDLER,
      COMPILE_FBLOCK_ASYNC_COMPREHENSION_GENERATOR,
+     COMPILE_FBLOCK_INLINED_COMPREHENSION,
      COMPILE_FBLOCK_STOP_ITERATION,
 };
 

Lib/asyncio/base_events.py

@@ -1497,7 +1497,12 @@ async def create_datagram_endpoint(self, protocol_factory,
             else:
                 raise exceptions[0]
 
-        protocol = protocol_factory()
+        try:
+            protocol = protocol_factory()
+        except:
+            # gh-156400: no transport owns the socket yet, so close it.
+            sock.close()
+            raise
         waiter = self.create_future()
         transport = self._make_datagram_transport(
             sock, protocol, r_addr, waiter)
@@ -1714,7 +1719,12 @@ async def connect_accepted_socket(
         return transport, protocol
 
     async def connect_read_pipe(self, protocol_factory, pipe):
-        protocol = protocol_factory()
+        try:
+            protocol = protocol_factory()
+        except:
+            # gh-156400: no transport owns the pipe yet, so close it.
+            pipe.close()
+            raise
         waiter = self.create_future()
         transport = self._make_read_pipe_transport(pipe, protocol, waiter)
 
@@ -1730,7 +1740,12 @@ async def connect_read_pipe(self, protocol_factory, pipe):
         return transport, protocol
 
     async def connect_write_pipe(self, protocol_factory, pipe):
-        protocol = protocol_factory()
+        try:
+            protocol = protocol_factory()
+        except:
+            # gh-156400: no transport owns the pipe yet, so close it.
+            pipe.close()
+            raise
         waiter = self.create_future()
         transport = self._make_write_pipe_transport(pipe, protocol, waiter)
 

Lib/asyncio/graph.py

@@ -155,7 +155,9 @@ def capture_call_graph(
     f = sys._getframe(depth) if limit != 0 else None
     try:
         while f is not None:
-            is_async = f.f_generator is not None
+            # gh-156988: sync gen should not clear the call chain
+            is_async = isinstance(
+                f.f_generator, (types.CoroutineType, types.AsyncGeneratorType))
             call_stack.append(FrameCallGraphEntry(f))
 
             if is_async:

Lib/asyncio/proactor_events.py

@@ -797,8 +797,8 @@ async def _sock_sendfile_native(self, sock, file, offset, count):
     async def _sendfile_native(self, transp, file, offset, count):
         resume_reading = transp.is_reading()
         transp.pause_reading()
-        await transp._make_empty_waiter()
         try:
+            await transp._make_empty_waiter()
             return await self.sock_sendfile(transp._sock, file, offset, count,
                                             fallback=False)
         finally:

Lib/asyncio/selector_events.py

@@ -739,8 +739,8 @@ async def _sendfile_native(self, transp, file, offset, count):
         del self._transports[transp._sock_fd]
         resume_reading = transp.is_reading()
         transp.pause_reading()
-        await transp._make_empty_waiter()
         try:
+            await transp._make_empty_waiter()
             return await self.sock_sendfile(transp._sock, file, offset, count,
                                             fallback=False)
         finally:
@@ -1127,7 +1127,9 @@ def _write_sendmsg(self):
                 self._loop._remove_writer(self._sock_fd)
                 if self._empty_waiter is not None:
                     self._empty_waiter.set_result(None)
-                if self._closing:
+                # gh-156512: don't let _call_connection_lost be called twice
+                if self._closing and not self._conn_lost:
+                    self._conn_lost += 1
                     self._call_connection_lost(None)
                 elif self._eof:
                     self._sock.shutdown(socket.SHUT_WR)
@@ -1173,7 +1175,9 @@ def _write_send(self):
                 self._loop._remove_writer(self._sock_fd)
                 if self._empty_waiter is not None:
                     self._empty_waiter.set_result(None)
-                if self._closing:
+                # gh-156512: don't let _call_connection_lost be called twice
+                if self._closing and not self._conn_lost:
+                    self._conn_lost += 1
                     self._call_connection_lost(None)
                 elif self._eof:
                     self._sock.shutdown(socket.SHUT_WR)

Lib/difflib.py

@@ -31,7 +31,7 @@
            'unified_diff', 'diff_bytes', 'HtmlDiff', 'Match']
 
 from heapq import nlargest as _nlargest
-from collections import namedtuple as _namedtuple
+from collections import deque as _deque, namedtuple as _namedtuple
 from types import GenericAlias
 lazy from _colorize import can_colorize, get_theme
 
@@ -1571,7 +1571,7 @@ def _line_pair_iterator():
         is defined) does not need to be of module scope.
         """
         line_iterator = _line_iterator()
-        fromlines,tolines=[],[]
+        fromlines, tolines = _deque(), _deque()
         while True:
             # Collecting lines of text until we have a from/to pair
             while (len(fromlines)==0 or len(tolines)==0):
@@ -1584,8 +1584,8 @@ def _line_pair_iterator():
                 if to_line is not None:
                     tolines.append((to_line,found_diff))
             # Once we have a pair, remove them from the collection and yield it
-            from_line, fromDiff = fromlines.pop(0)
-            to_line, to_diff = tolines.pop(0)
+            from_line, fromDiff = fromlines.popleft()
+            to_line, to_diff = tolines.popleft()
             yield (from_line,to_line,fromDiff or to_diff)
 
     # Handle case where user does not want context differencing, just yield

Lib/idlelib/editor.py

@@ -26,8 +26,7 @@
 from idlelib import query
 from idlelib import replace
 from idlelib import search
-from idlelib.tree import wheel_event
-from idlelib.util import py_extensions
+from idlelib.util import bind_wheel, py_extensions, wheel_event
 from idlelib import window
 from idlelib.help import _get_dochome
 
@@ -115,10 +114,7 @@ def __init__(self, flist=None, filename=None, key=None, root=None):
             # Elsewhere, use right-click for popup menus.
             text.bind("<3>",self.right_menu_event)
 
-        text.bind('<MouseWheel>', wheel_event)
-        if text._windowingsystem == 'x11':
-            text.bind('<Button-4>', wheel_event)
-            text.bind('<Button-5>', wheel_event)
+        bind_wheel(text, wheel_event)
         text.bind('<Configure>', self.handle_winconfig)
         text.bind("<<cut>>", self.cut)
         text.bind("<<copy>>", self.copy)

Lib/idlelib/idle_test/test_configdialog.py

@@ -150,8 +150,8 @@ def test_fontlist_key(self):
         font = d.fontlist.get('active')
 
         # Test Down key.
-        fontlist.focus_force()
         fontlist.update()
+        fontlist.focus_force()
         fontlist.event_generate('<Key-Down>')
         fontlist.event_generate('<KeyRelease-Down>')
 
@@ -160,8 +160,8 @@ def test_fontlist_key(self):
         self.assertIn(d.font_name.get(), down_font.lower())
 
         # Test Up key.
-        fontlist.focus_force()
         fontlist.update()
+        fontlist.focus_force()
         fontlist.event_generate('<Key-Up>')
         fontlist.event_generate('<KeyRelease-Up>')
 

Lib/idlelib/idle_test/test_sidebar.py

@@ -14,7 +14,8 @@
 from idlelib.percolator import Percolator
 import idlelib.pyshell
 from idlelib.pyshell import PyShell, PyShellFileList
-from idlelib.util import fix_scaling, fix_word_breaks, fix_x11_paste
+from idlelib.util import (fix_scaling, fix_word_breaks, fix_x11_paste,
+                          x11_buttons)
 import idlelib.sidebar
 from idlelib.sidebar import get_end_linenumber, get_lineno
 
@@ -689,23 +690,21 @@ def test_mousewheel(self):
         last_lineno = get_end_linenumber(text)
         self.assertIsNotNone(text.dlineinfo(text.index(f'{last_lineno}.0')))
 
-        # Simulate a mouse wheel notch.  Tk 8.7 replaced the X11
-        # <Button-4>/<Button-5> wheel events with <MouseWheel> (whose delta is
-        # platform-dependent); older Tk on X11 still uses the button events.
-        x11_buttons = (sidebar.canvas._windowingsystem == 'x11'
-                       and tk.TkVersion < 8.7)
+        # Simulate a mouse wheel notch with the events that Tk sends for
+        # one; the delta of a <MouseWheel> event is platform-dependent.
+        buttons = x11_buttons(sidebar.canvas)
         delta = 1 if sidebar.canvas._windowingsystem == 'aqua' else 120
 
         # Scroll up.
-        if x11_buttons:
+        if buttons:
             sidebar.canvas.event_generate('<Button-4>', x=0, y=0)
         else:
             sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=delta)
         yield
         self.assertIsNone(text.dlineinfo(text.index(f'{last_lineno}.0')))
 
         # Scroll back down.
-        if x11_buttons:
+        if buttons:
             sidebar.canvas.event_generate('<Button-5>', x=0, y=0)
         else:
             sidebar.canvas.event_generate('<MouseWheel>', x=0, y=0, delta=-delta)