Merge branch 'main' into 145247-pytuple-from-pair

sergey-miryanov · web-flow · commit e061960eacb5 · 2026-03-10T01:29:08.000+05:00
diff --git a/Doc/conf.py b/Doc/conf.py
@@ -557,6 +557,7 @@
 # mapping unique short aliases to a base URL and a prefix.
 # https://www.sphinx-doc.org/en/master/usage/extensions/extlinks.html
 extlinks = {
+    "oss-fuzz": ("https://issues.oss-fuzz.com/issues/%s", "#%s"),
     "pypi": ("https://pypi.org/project/%s/", "%s"),
     "source": (SOURCE_URI, "%s"),
 }
diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst
diff --git a/Doc/installing/index.rst b/Doc/installing/index.rst
@@ -6,8 +6,6 @@
 Installing Python Modules
 *************************
 
-:Email: distutils-sig@python.org
-
 As a popular open source development project, Python has an active
 supporting community of contributors and users that also make their software
 available for other Python developers to use under open source license terms.
diff --git a/Lib/_ast_unparse.py b/Lib/_ast_unparse.py
@@ -738,9 +738,13 @@ def visit_SetComp(self, node):
 
     def visit_DictComp(self, node):
         with self.delimit("{", "}"):
-            self.traverse(node.key)
-            self.write(": ")
-            self.traverse(node.value)
+            if node.value:
+                self.traverse(node.key)
+                self.write(": ")
+                self.traverse(node.value)
+            else:
+                self.write("**")
+                self.traverse(node.key)
             for gen in node.generators:
                 self.traverse(gen)
 
diff --git a/Lib/test/test_future_stmt/test_future.py b/Lib/test/test_future_stmt/test_future.py
@@ -349,6 +349,8 @@ def test_annotations(self):
         eq("(i ** 2 + j for i in (1, 2, 3) for j in (1, 2, 3))")
         eq("{i: 0 for i in (1, 2, 3)}")
         eq("{i: j for i, j in ((1, 'a'), (2, 'b'), (3, 'c'))}")
+        eq("{**x for x in ()}")
+        eq("[*x for x in ()]")
         eq("[(x, y) for x, y in (a, b)]")
         eq("[(x,) for x, in (a,)]")
         eq("Python3 > Python2 > COBOL")
diff --git a/Lib/test/test_listcomps.py b/Lib/test/test_listcomps.py
@@ -180,6 +180,18 @@ def test_references___class___defined(self):
                 code, outputs={"res": [2]}, scopes=["module", "function"])
         self._check_in_scopes(code, raises=NameError, scopes=["class"])
 
+    def test_references___classdict__(self):
+        code = """
+            class i: [__classdict__ for x in y]
+        """
+        self._check_in_scopes(code, raises=NameError)
+
+    def test_references___conditional_annotations__(self):
+        code = """
+            class i: [__conditional_annotations__ for x in y]
+        """
+        self._check_in_scopes(code, raises=NameError)
+
     def test_references___class___enclosing(self):
         code = """
             __class__ = 2
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
@@ -403,6 +403,11 @@ def test_set_comprehension(self):
     def test_dict_comprehension(self):
         self.check_ast_roundtrip("{x: x*x for x in range(10)}")
 
+    def test_dict_comprehension_unpacking(self):
+        self.check_ast_roundtrip("{**x for x in ()}")
+        self.check_ast_roundtrip("{**x for x in range(10)}")
+        self.check_ast_roundtrip("[*x for x in ()]")
+
     def test_class_decorators(self):
         self.check_ast_roundtrip(class_decorator)
 
diff --git a/Makefile.pre.in b/Makefile.pre.in
@@ -1729,9 +1729,6 @@ FROZEN_FILES_IN = \
 		Lib/zipimport.py \
 		Lib/abc.py \
 		Lib/codecs.py \
-		Lib/encodings/__init__.py \
-		Lib/encodings/aliases.py \
-		Lib/encodings/utf_8.py \
 		Lib/io.py \
 		Lib/_collections_abc.py \
 		Lib/_sitebuiltins.py \
@@ -1741,7 +1738,6 @@ FROZEN_FILES_IN = \
 		Lib/os.py \
 		Lib/site.py \
 		Lib/stat.py \
-		Lib/linecache.py \
 		Lib/importlib/util.py \
 		Lib/importlib/machinery.py \
 		Lib/runpy.py \
@@ -1758,9 +1754,6 @@ FROZEN_FILES_OUT = \
 		Python/frozen_modules/zipimport.h \
 		Python/frozen_modules/abc.h \
 		Python/frozen_modules/codecs.h \
-		Python/frozen_modules/encodings.h \
-		Python/frozen_modules/encodings.aliases.h \
-		Python/frozen_modules/encodings.utf_8.h \
 		Python/frozen_modules/io.h \
 		Python/frozen_modules/_collections_abc.h \
 		Python/frozen_modules/_sitebuiltins.h \
@@ -1770,7 +1763,6 @@ FROZEN_FILES_OUT = \
 		Python/frozen_modules/os.h \
 		Python/frozen_modules/site.h \
 		Python/frozen_modules/stat.h \
-		Python/frozen_modules/linecache.h \
 		Python/frozen_modules/importlib.util.h \
 		Python/frozen_modules/importlib.machinery.h \
 		Python/frozen_modules/runpy.h \
@@ -1810,15 +1802,6 @@ Python/frozen_modules/abc.h: Lib/abc.py $(FREEZE_MODULE_DEPS)
 Python/frozen_modules/codecs.h: Lib/codecs.py $(FREEZE_MODULE_DEPS)
 	$(FREEZE_MODULE) codecs $(srcdir)/Lib/codecs.py Python/frozen_modules/codecs.h
 
-Python/frozen_modules/encodings.h: Lib/encodings/__init__.py $(FREEZE_MODULE_DEPS)
-	$(FREEZE_MODULE) encodings $(srcdir)/Lib/encodings/__init__.py Python/frozen_modules/encodings.h
-
-Python/frozen_modules/encodings.aliases.h: Lib/encodings/aliases.py $(FREEZE_MODULE_DEPS)
-	$(FREEZE_MODULE) encodings.aliases $(srcdir)/Lib/encodings/aliases.py Python/frozen_modules/encodings.aliases.h
-
-Python/frozen_modules/encodings.utf_8.h: Lib/encodings/utf_8.py $(FREEZE_MODULE_DEPS)
-	$(FREEZE_MODULE) encodings.utf_8 $(srcdir)/Lib/encodings/utf_8.py Python/frozen_modules/encodings.utf_8.h
-
 Python/frozen_modules/io.h: Lib/io.py $(FREEZE_MODULE_DEPS)
 	$(FREEZE_MODULE) io $(srcdir)/Lib/io.py Python/frozen_modules/io.h
 
@@ -1846,9 +1829,6 @@ Python/frozen_modules/site.h: Lib/site.py $(FREEZE_MODULE_DEPS)
 Python/frozen_modules/stat.h: Lib/stat.py $(FREEZE_MODULE_DEPS)
 	$(FREEZE_MODULE) stat $(srcdir)/Lib/stat.py Python/frozen_modules/stat.h
 
-Python/frozen_modules/linecache.h: Lib/linecache.py $(FREEZE_MODULE_DEPS)
-	$(FREEZE_MODULE) linecache $(srcdir)/Lib/linecache.py Python/frozen_modules/linecache.h
-
 Python/frozen_modules/importlib.util.h: Lib/importlib/util.py $(FREEZE_MODULE_DEPS)
 	$(FREEZE_MODULE) importlib.util $(srcdir)/Lib/importlib/util.py Python/frozen_modules/importlib.util.h
 
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-02-26-21-22-34.gh-issue-145278.DHkYqt.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-26-21-22-34.gh-issue-145278.DHkYqt.rst
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst
@@ -0,0 +1,2 @@
+Fix crash in AST unparser when unparsing dict comprehension unpacking.
+Found by OSS Fuzz in :oss-fuzz:`489790200`.
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-06-21-05-05.gh-issue-145615.NKXXZgDW.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-06-21-05-05.gh-issue-145615.NKXXZgDW.rst
@@ -0,0 +1,2 @@
+Fixed a memory leak in the :term:`free-threaded build` where mimalloc pages
+could become permanently unreclaimable until the owning thread exited.
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-09-18-52-03.gh-issue-145701.79KQyO.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-09-18-52-03.gh-issue-145701.79KQyO.rst
@@ -0,0 +1,3 @@
+Fix :exc:`SystemError` when ``__classdict__`` or
+``__conditional_annotations__`` is in a class-scope inlined comprehension.
+Found by OSS Fuzz in :oss-fuzz:`491105000`.
diff --git a/Modules/getpath.py b/Modules/getpath.py
@@ -776,9 +776,9 @@ def search_up(prefix, *landmarks, test=isfile):
 # Warn if the standard library is missing, unless pythonpath_was_set was set, as
 # that skips parts of the stdlib directories calculation — assume the provided
 # pythonpath is correct. This is how subinterpreters initialize the path for eg.
-if not py_setpath and not pythonpath_was_set and (not stdlib_zip or not isfile(stdlib_zip)):
+if not py_setpath and not pythonpath_was_set:
     home_hint = f"The Python 'home' directory was set to {home!r}, is this correct?"
-    if not stdlib_dir or not isdir(stdlib_dir):
+    if (not stdlib_zip or not isfile(stdlib_zip)) and (not stdlib_dir or not isdir(stdlib_dir)):
         hint = home_hint if home else f'sys.prefix is set to {prefix}, is this correct?'
         warn('WARN: Could not find the standard library directory! ' + hint)
     elif not platstdlib_dir or not isdir(platstdlib_dir):
diff --git a/Objects/mimalloc/heap.c b/Objects/mimalloc/heap.c
@@ -100,7 +100,10 @@ static bool mi_heap_page_collect(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_t
     // note: this will free retired pages as well.
     bool freed = _PyMem_mi_page_maybe_free(page, pq, collect >= MI_FORCE);
     if (!freed && collect == MI_ABANDON) {
-      _mi_page_abandon(page, pq);
+      // _PyMem_mi_page_maybe_free may have moved the page to a different
+      // page queue, so we need to re-fetch the correct queue.
+      uint8_t bin = (mi_page_is_in_full(page) ? MI_BIN_FULL : _mi_bin(page->xblock_size));
+      _mi_page_abandon(page, &heap->pages[bin]);
     }
   }
   else if (collect == MI_ABANDON) {
diff --git a/Objects/mimalloc/page.c b/Objects/mimalloc/page.c
@@ -213,6 +213,13 @@ static void _mi_page_thread_free_collect(mi_page_t* page)
 
   // update counts now
   page->used -= count;
+
+  if (page->used == 0) {
+    // The page may have had a QSBR goal set from a previous point when it
+    // was all-free. That goal is no longer valid because the page was
+    // allocated from and then freed again by other threads.
+    _PyMem_mi_page_clear_qsbr(page);
+  }
 }
 
 void _mi_page_free_collect(mi_page_t* page, bool force) {
@@ -225,9 +232,6 @@ void _mi_page_free_collect(mi_page_t* page, bool force) {
 
   // and the local free list
   if (page->local_free != NULL) {
-    // any previous QSBR goals are no longer valid because we reused the page
-    _PyMem_mi_page_clear_qsbr(page);
-
     if mi_likely(page->free == NULL) {
       // usual case
       page->free = page->local_free;
diff --git a/Objects/mimalloc/segment.c b/Objects/mimalloc/segment.c
@@ -1286,6 +1286,7 @@ static bool mi_segment_check_free(mi_segment_t* segment, size_t slices_needed, s
         _mi_stat_decrease(&tld->stats->pages_abandoned, 1);
 #ifdef Py_GIL_DISABLED
         page->qsbr_goal = 0;
+        mi_assert_internal(page->qsbr_node.next == NULL);
 #endif
         segment->abandoned--;
         slice = mi_segment_page_clear(page, tld); // re-assign slice due to coalesce!
@@ -1361,6 +1362,7 @@ static mi_segment_t* mi_segment_reclaim(mi_segment_t* segment, mi_heap_t* heap,
         // if everything free by now, free the page
 #ifdef Py_GIL_DISABLED
         page->qsbr_goal = 0;
+        mi_assert_internal(page->qsbr_node.next == NULL);
 #endif
         slice = mi_segment_page_clear(page, tld);   // set slice again due to coalesceing
       }
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
@@ -151,6 +151,12 @@ should_advance_qsbr_for_page(struct _qsbr_thread_state *qsbr, mi_page_t *page)
     }
     return false;
 }
+
+static _PyThreadStateImpl *
+tstate_from_heap(mi_heap_t *heap)
+{
+    return _Py_CONTAINER_OF(heap->tld, _PyThreadStateImpl, mimalloc.tld);
+}
 #endif
 
 static bool
@@ -159,23 +165,35 @@ _PyMem_mi_page_maybe_free(mi_page_t *page, mi_page_queue_t *pq, bool force)
 #ifdef Py_GIL_DISABLED
     assert(mi_page_all_free(page));
     if (page->use_qsbr) {
-        _PyThreadStateImpl *tstate = (_PyThreadStateImpl *)PyThreadState_GET();
-        if (page->qsbr_goal != 0 && _Py_qbsr_goal_reached(tstate->qsbr, page->qsbr_goal)) {
+        struct _qsbr_thread_state *qsbr = ((_PyThreadStateImpl *)PyThreadState_GET())->qsbr;
+        if (page->qsbr_goal != 0 && _Py_qbsr_goal_reached(qsbr, page->qsbr_goal)) {
             _PyMem_mi_page_clear_qsbr(page);
             _mi_page_free(page, pq, force);
             return true;
         }
 
+        // gh-145615: since we are not freeing this page yet, we want to
+        // make it available for allocations. Note that the QSBR goal and
+        // linked list node remain set even if the page is later used for
+        // an allocation. We only detect and clear the QSBR goal when the
+        // page becomes empty again (used == 0).
+        if (mi_page_is_in_full(page)) {
+            _mi_page_unfull(page);
+        }
+
         _PyMem_mi_page_clear_qsbr(page);
         page->retire_expire = 0;
 
-        if (should_advance_qsbr_for_page(tstate->qsbr, page)) {
-            page->qsbr_goal = _Py_qsbr_advance(tstate->qsbr->shared);
+        if (should_advance_qsbr_for_page(qsbr, page)) {
+            page->qsbr_goal = _Py_qsbr_advance(qsbr->shared);
         }
         else {
-            page->qsbr_goal = _Py_qsbr_shared_next(tstate->qsbr->shared);
+            page->qsbr_goal = _Py_qsbr_shared_next(qsbr->shared);
         }
 
+        // We may be freeing a page belonging to a different thread during a
+        // stop-the-world event. Find the _PyThreadStateImpl for the page.
+        _PyThreadStateImpl *tstate = tstate_from_heap(mi_page_heap(page));
         llist_insert_tail(&tstate->mimalloc.page_list, &page->qsbr_node);
         return false;
     }
@@ -192,7 +210,8 @@ _PyMem_mi_page_reclaimed(mi_page_t *page)
     if (page->qsbr_goal != 0) {
         if (mi_page_all_free(page)) {
             assert(page->qsbr_node.next == NULL);
-            _PyThreadStateImpl *tstate = (_PyThreadStateImpl *)PyThreadState_GET();
+            _PyThreadStateImpl *tstate = tstate_from_heap(mi_page_heap(page));
+            assert(tstate == (_PyThreadStateImpl *)_PyThreadState_GET());
             page->retire_expire = 0;
             llist_insert_tail(&tstate->mimalloc.page_list, &page->qsbr_node);
         }
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
@@ -310,21 +310,6 @@
       <IntFile>$(IntDir)codecs.g.h</IntFile>
       <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\codecs.h</OutFile>
     </None>
-    <None Include="..\Lib\encodings\__init__.py">
-      <ModName>encodings</ModName>
-      <IntFile>$(IntDir)encodings.g.h</IntFile>
-      <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\encodings.h</OutFile>
-    </None>
-    <None Include="..\Lib\encodings\aliases.py">
-      <ModName>encodings.aliases</ModName>
-      <IntFile>$(IntDir)encodings.aliases.g.h</IntFile>
-      <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\encodings.aliases.h</OutFile>
-    </None>
-    <None Include="..\Lib\encodings\utf_8.py">
-      <ModName>encodings.utf_8</ModName>
-      <IntFile>$(IntDir)encodings.utf_8.g.h</IntFile>
-      <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\encodings.utf_8.h</OutFile>
-    </None>
     <None Include="..\Lib\io.py">
       <ModName>io</ModName>
       <IntFile>$(IntDir)io.g.h</IntFile>
@@ -370,11 +355,6 @@
       <IntFile>$(IntDir)stat.g.h</IntFile>
       <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\stat.h</OutFile>
     </None>
-    <None Include="..\Lib\linecache.py">
-      <ModName>linecache</ModName>
-      <IntFile>$(IntDir)linecache.g.h</IntFile>
-      <OutFile>$(GeneratedFrozenModulesDir)Python\frozen_modules\linecache.h</OutFile>
-    </None>
     <None Include="..\Lib\importlib\util.py">
       <ModName>importlib.util</ModName>
       <IntFile>$(IntDir)importlib.util.g.h</IntFile>
diff --git a/PCbuild/_freeze_module.vcxproj.filters b/PCbuild/_freeze_module.vcxproj.filters
@@ -537,15 +537,6 @@
     <None Include="..\Lib\codecs.py">
       <Filter>Python Files</Filter>
     </None>
-    <None Include="..\Lib\encodings\__init__.py">
-      <Filter>Python Files</Filter>
-    </None>
-    <None Include="..\Lib\encodings\aliases.py">
-      <Filter>Python Files</Filter>
-    </None>
-    <None Include="..\Lib\encodings\utf_8.py">
-      <Filter>Python Files</Filter>
-    </None>
     <None Include="..\Lib\io.py">
       <Filter>Python Files</Filter>
     </None>
@@ -573,9 +564,6 @@
     <None Include="..\Lib\stat.py">
       <Filter>Python Files</Filter>
     </None>
-    <None Include="..\Lib\linecache.py">
-      <Filter>Python Files</Filter>
-    </None>
     <None Include="..\Lib\importlib\util.py">
       <Filter>Python Files</Filter>
     </None>
diff --git a/Python/ast_unparse.c b/Python/ast_unparse.c
@@ -464,9 +464,15 @@ static int
 append_ast_dictcomp(PyUnicodeWriter *writer, expr_ty e)
 {
     APPEND_CHAR('{');
-    APPEND_EXPR(e->v.DictComp.key, PR_TEST);
-    APPEND_STR(": ");
-    APPEND_EXPR(e->v.DictComp.value, PR_TEST);
+    if (e->v.DictComp.value) {
+        APPEND_EXPR(e->v.DictComp.key, PR_TEST);
+        APPEND_STR(": ");
+        APPEND_EXPR(e->v.DictComp.value, PR_TEST);
+    }
+    else {
+        APPEND_STR("**");
+        APPEND_EXPR(e->v.DictComp.key, PR_TEST);
+    }
     APPEND(comprehensions, e->v.DictComp.generators);
     APPEND_CHAR_FINISH('}');
 }
diff --git a/Python/frozen.c b/Python/frozen.c
@@ -46,9 +46,6 @@
 #include "frozen_modules/zipimport.h"
 #include "frozen_modules/abc.h"
 #include "frozen_modules/codecs.h"
-#include "frozen_modules/encodings.h"
-#include "frozen_modules/encodings.aliases.h"
-#include "frozen_modules/encodings.utf_8.h"
 #include "frozen_modules/io.h"
 #include "frozen_modules/_collections_abc.h"
 #include "frozen_modules/_sitebuiltins.h"
@@ -58,7 +55,6 @@
 #include "frozen_modules/os.h"
 #include "frozen_modules/site.h"
 #include "frozen_modules/stat.h"
-#include "frozen_modules/linecache.h"
 #include "frozen_modules/importlib.util.h"
 #include "frozen_modules/importlib.machinery.h"
 #include "frozen_modules/runpy.h"
@@ -80,9 +76,6 @@ static const struct _frozen stdlib_modules[] = {
     /* stdlib - startup, without site (python -S) */
     {"abc", _Py_M__abc, (int)sizeof(_Py_M__abc), false},
     {"codecs", _Py_M__codecs, (int)sizeof(_Py_M__codecs), false},
-    {"encodings", _Py_M__encodings, (int)sizeof(_Py_M__encodings), true},
-    {"encodings.aliases", _Py_M__encodings_aliases, (int)sizeof(_Py_M__encodings_aliases), false},
-    {"encodings.utf_8", _Py_M__encodings_utf_8, (int)sizeof(_Py_M__encodings_utf_8), false},
     {"io", _Py_M__io, (int)sizeof(_Py_M__io), false},
 
     /* stdlib - startup, with site */
@@ -95,9 +88,6 @@ static const struct _frozen stdlib_modules[] = {
     {"site", _Py_M__site, (int)sizeof(_Py_M__site), false},
     {"stat", _Py_M__stat, (int)sizeof(_Py_M__stat), false},
 
-    /* pythonrun - interactive */
-    {"linecache", _Py_M__linecache, (int)sizeof(_Py_M__linecache), false},
-
     /* runpy - run module with -m */
     {"importlib.util", _Py_M__importlib_util, (int)sizeof(_Py_M__importlib_util), false},
     {"importlib.machinery", _Py_M__importlib_machinery, (int)sizeof(_Py_M__importlib_machinery), false},
diff --git a/Python/symtable.c b/Python/symtable.c
diff --git a/Tools/build/freeze_modules.py b/Tools/build/freeze_modules.py

Original file line number	Diff line number	Diff line change
`@@ -557,6 +557,7 @@`
`557`	`557`	`# mapping unique short aliases to a base URL and a prefix.`
`558`	`558`	`# https://www.sphinx-doc.org/en/master/usage/extensions/extlinks.html`
`559`	`559`	`extlinks = {`
	`560`	`+ "oss-fuzz": ("https://issues.oss-fuzz.com/issues/%s", "#%s"),`
`560`	`561`	`"pypi": ("https://pypi.org/project/%s/", "%s"),`
`561`	`562`	`"source": (SOURCE_URI, "%s"),`
`562`	`563`	`}`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Fix crash in AST unparser when unparsing dict comprehension unpacking.`
	`2`	+Found by OSS Fuzz in :oss-fuzz:`489790200`.