[pull] main from python:main

Include/cpython/pystate.h

@@ -135,6 +135,8 @@ struct _ts {
     /* Pointer to currently executing frame. */
     struct _PyInterpreterFrame *current_frame;
 
+    struct _PyInterpreterFrame *last_profiled_frame;
+
     Py_tracefunc c_profilefunc;
     Py_tracefunc c_tracefunc;
     PyObject *c_profileobj;

Include/internal/pycore_debug_offsets.h

@@ -102,6 +102,7 @@ typedef struct _Py_DebugOffsets {
         uint64_t next;
         uint64_t interp;
         uint64_t current_frame;
+        uint64_t last_profiled_frame;
         uint64_t thread_id;
         uint64_t native_thread_id;
         uint64_t datastack_chunk;
@@ -272,6 +273,7 @@ typedef struct _Py_DebugOffsets {
         .next = offsetof(PyThreadState, next), \
         .interp = offsetof(PyThreadState, interp), \
         .current_frame = offsetof(PyThreadState, current_frame), \
+        .last_profiled_frame = offsetof(PyThreadState, last_profiled_frame), \
         .thread_id = offsetof(PyThreadState, thread_id), \
         .native_thread_id = offsetof(PyThreadState, native_thread_id), \
         .datastack_chunk = offsetof(PyThreadState, datastack_chunk), \

Include/internal/pycore_global_strings.h

@@ -332,6 +332,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(c_parameter_type)
         STRUCT_FOR_ID(c_return)
         STRUCT_FOR_ID(c_stack)
+        STRUCT_FOR_ID(cache_frames)
         STRUCT_FOR_ID(cached_datetime_module)
         STRUCT_FOR_ID(cached_statements)
         STRUCT_FOR_ID(cadata)
@@ -776,6 +777,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(stacklevel)
         STRUCT_FOR_ID(start)
         STRUCT_FOR_ID(statement)
+        STRUCT_FOR_ID(stats)
         STRUCT_FOR_ID(status)
         STRUCT_FOR_ID(stderr)
         STRUCT_FOR_ID(stdin)

InternalDocs/frames.md

@@ -111,6 +111,26 @@ The shim frame points to a special code object containing the `INTERPRETER_EXIT`
 instruction which cleans up the shim frame and returns.
 
 
+### Remote Profiling Frame Cache
+
+The `last_profiled_frame` field in `PyThreadState` supports an optimization for
+remote profilers that sample call stacks from external processes. When a remote
+profiler reads the call stack, it writes the current frame address to this field.
+The eval loop then keeps this pointer valid by updating it to the parent frame
+whenever a frame returns (in `_PyEval_FrameClearAndPop`).
+
+This creates a "high-water mark" that always points to a frame still on the stack.
+On subsequent samples, the profiler can walk from `current_frame` until it reaches
+`last_profiled_frame`, knowing that frames from that point downward are unchanged
+and can be retrieved from a cache. This significantly reduces the amount of remote
+memory reads needed when call stacks are deep and stable at their base.
+
+The update in `_PyEval_FrameClearAndPop` is guarded: it only writes when
+`last_profiled_frame` is non-NULL AND matches the frame being popped. This
+prevents transient frames (called and returned between profiler samples) from
+corrupting the cache pointer, while avoiding any overhead when profiling is inactive.
+
+
 ### The Instruction Pointer
 
 `_PyInterpreterFrame` has two fields which are used to maintain the instruction

Lib/argparse.py

@@ -467,16 +467,12 @@ def _get_actions_usage_parts_with_split(self, actions, groups, opt_count=None):
             # produce all arg strings
             elif not action.option_strings:
                 default = self._get_default_metavar_for_positional(action)
-                part = (
-                    t.summary_action
-                    + self._format_args(action, default)
-                    + t.reset
-                )
-
+                part = self._format_args(action, default)
                 # if it's in a group, strip the outer []
                 if action in group_actions:
                     if part[0] == '[' and part[-1] == ']':
                         part = part[1:-1]
+                part = t.summary_action + part + t.reset
 
             # produce the first way to invoke the option in brackets
             else:
@@ -2008,14 +2004,16 @@ def add_subparsers(self, **kwargs):
             self._subparsers = self._positionals
 
         # prog defaults to the usage message of this parser, skipping
-        # optional arguments and with no "usage:" prefix
+        # non-required optional arguments and with no "usage:" prefix
         if kwargs.get('prog') is None:
             # Create formatter without color to avoid storing ANSI codes in prog
             formatter = self.formatter_class(prog=self.prog)
             formatter._set_color(False)
             positionals = self._get_positional_actions()
+            required_optionals = [action for action in self._get_optional_actions()
+                                  if action.required]
             groups = self._mutually_exclusive_groups
-            formatter.add_usage(None, positionals, groups, '')
+            formatter.add_usage(None, required_optionals + positionals, groups, '')
             kwargs['prog'] = formatter.format_help().strip()
 
         # create the parsers action and add it to the positionals list

Lib/asyncio/futures.py

@@ -389,7 +389,7 @@ def _set_state(future, other):
 
     def _call_check_cancel(destination):
         if destination.cancelled():
-            if source_loop is None or source_loop is dest_loop:
+            if source_loop is None or source_loop is events._get_running_loop():
                 source.cancel()
             else:
                 source_loop.call_soon_threadsafe(source.cancel)
@@ -398,7 +398,7 @@ def _call_set_state(source):
         if (destination.cancelled() and
                 dest_loop is not None and dest_loop.is_closed()):
             return
-        if dest_loop is None or dest_loop is source_loop:
+        if dest_loop is None or dest_loop is events._get_running_loop():
             _set_state(destination, source)
         else:
             if dest_loop.is_closed():

Lib/doctest.py

@@ -1167,6 +1167,32 @@ def _find_lineno(self, obj, source_lines):
                 if pat.match(source_lines[lineno]):
                     return lineno
 
+        # Handle __test__ string doctests formatted as triple-quoted
+        # strings. Find a non-blank line in the test string and match it
+        # in the source, verifying subsequent lines also match to handle
+        # duplicate lines.
+        if isinstance(obj, str) and source_lines is not None:
+            obj_lines = obj.splitlines(keepends=True)
+            # Skip the first line (may be on same line as opening quotes)
+            # and any blank lines to find a meaningful line to match.
+            start_index = 1
+            while (start_index < len(obj_lines)
+                   and not obj_lines[start_index].strip()):
+                start_index += 1
+            if start_index < len(obj_lines):
+                target_line = obj_lines[start_index]
+                for lineno, source_line in enumerate(source_lines):
+                    if source_line == target_line:
+                        # Verify subsequent lines also match
+                        for i in range(start_index + 1, len(obj_lines) - 1):
+                            source_idx = lineno + i - start_index
+                            if source_idx >= len(source_lines):
+                                break
+                            if obj_lines[i] != source_lines[source_idx]:
+                                break
+                        else:
+                            return lineno - start_index
+
         # We couldn't find the line number.
         return None
 

Lib/email/_header_value_parser.py

@@ -2792,6 +2792,9 @@ def _steal_trailing_WSP_if_exists(lines):
     if lines and lines[-1] and lines[-1][-1] in WSP:
         wsp = lines[-1][-1]
         lines[-1] = lines[-1][:-1]
+        # gh-142006: if the line is now empty, remove it entirely.
+        if not lines[-1]:
+            lines.pop()
     return wsp
 
 def _refold_parse_tree(parse_tree, *, policy):

Lib/email/feedparser.py

@@ -504,10 +504,9 @@ def _parse_headers(self, lines):
                     self._input.unreadline(line)
                     return
                 else:
-                    # Weirdly placed unix-from line.  Note this as a defect
-                    # and ignore it.
+                    # Weirdly placed unix-from line.
                     defect = errors.MisplacedEnvelopeHeaderDefect(line)
-                    self._cur.defects.append(defect)
+                    self.policy.handle_defect(self._cur, defect)
                     continue
             # Split the line on the colon separating field name from value.
             # There will always be a colon, because if there wasn't the part of
@@ -519,7 +518,7 @@ def _parse_headers(self, lines):
             # message. Track the error but keep going.
             if i == 0:
                 defect = errors.InvalidHeaderDefect("Missing header name.")
-                self._cur.defects.append(defect)
+                self.policy.handle_defect(self._cur, defect)
                 continue
 
             assert i>0, "_parse_headers fed line with no : and no leading WS"

Lib/profiling/sampling/_heatmap_assets/heatmap.css

@@ -1094,18 +1094,34 @@
 }
 
 #scroll_marker .marker.cold {
+  background: var(--heat-1);
+}
+
+#scroll_marker .marker.cool {
   background: var(--heat-2);
 }
 
+#scroll_marker .marker.mild {
+  background: var(--heat-3);
+}
+
 #scroll_marker .marker.warm {
-  background: var(--heat-5);
+  background: var(--heat-4);
 }
 
 #scroll_marker .marker.hot {
+  background: var(--heat-5);
+}
+
+#scroll_marker .marker.very-hot {
+  background: var(--heat-6);
+}
+
+#scroll_marker .marker.intense {
   background: var(--heat-7);
 }
 
-#scroll_marker .marker.vhot {
+#scroll_marker .marker.extreme {
   background: var(--heat-8);
 }
 

Lib/profiling/sampling/_heatmap_assets/heatmap.js

@@ -26,6 +26,7 @@ function toggleTheme() {
     if (btn) {
         btn.innerHTML = next === 'dark' ? '☼' : '☾';  // sun or moon
     }
+    applyLineColors();
 
     // Rebuild scroll marker with new theme colors
     buildScrollMarker();
@@ -160,13 +161,6 @@ function getSampleCount(line) {
     return parseInt(text) || 0;
 }
 
-function getIntensityClass(ratio) {
-    if (ratio > 0.75) return 'vhot';
-    if (ratio > 0.5) return 'hot';
-    if (ratio > 0.25) return 'warm';
-    return 'cold';
-}
-
 // ============================================================================
 // Scroll Minimap
 // ============================================================================
@@ -194,7 +188,7 @@ function buildScrollMarker() {
 
         const lineTop = Math.floor(line.offsetTop * markerScale);
         const lineNumber = index + 1;
-        const intensityClass = maxSamples > 0 ? getIntensityClass(samples / maxSamples) : 'cold';
+        const intensityClass = maxSamples > 0 ? (intensityToClass(samples / maxSamples) || 'cold') : 'cold';
 
         if (lineNumber === prevLine + 1 && lastMark?.classList.contains(intensityClass)) {
             lastMark.style.height = `${lineTop + lineHeight - lastTop}px`;
@@ -212,6 +206,21 @@ function buildScrollMarker() {
     document.body.appendChild(scrollMarker);
 }
 
+function applyLineColors() {
+    const lines = document.querySelectorAll('.code-line');
+    lines.forEach(line => {
+        let intensity;
+        if (colorMode === 'self') {
+            intensity = parseFloat(line.getAttribute('data-self-intensity')) || 0;
+        } else {
+            intensity = parseFloat(line.getAttribute('data-cumulative-intensity')) || 0;
+        }
+
+        const color = intensityToColor(intensity);
+        line.style.background = color;
+    });
+}
+
 // ============================================================================
 // Toggle Controls
 // ============================================================================
@@ -264,20 +273,7 @@ function applyHotFilter() {
 
 function toggleColorMode() {
     colorMode = colorMode === 'self' ? 'cumulative' : 'self';
-    const lines = document.querySelectorAll('.code-line');
-
-    lines.forEach(line => {
-        let bgColor;
-        if (colorMode === 'self') {
-            bgColor = line.getAttribute('data-self-color');
-        } else {
-            bgColor = line.getAttribute('data-cumulative-color');
-        }
-
-        if (bgColor) {
-            line.style.background = bgColor;
-        }
-    });
+    applyLineColors();
 
     updateToggleUI('toggle-color-mode', colorMode === 'cumulative');
 
@@ -295,14 +291,7 @@ function toggleColorMode() {
 document.addEventListener('DOMContentLoaded', function() {
     // Restore UI state (theme, etc.)
     restoreUIState();
-
-    // Apply background colors
-    document.querySelectorAll('.code-line[data-bg-color]').forEach(line => {
-        const bgColor = line.getAttribute('data-bg-color');
-        if (bgColor) {
-            line.style.background = bgColor;
-        }
-    });
+    applyLineColors();
 
     // Initialize navigation buttons
     document.querySelectorAll('.nav-btn').forEach(button => {