[3.12] gh-128799: Add frame of except* to traceback when wrapping a naked exception (GH-128971) (#129328)

Lib/test/test_traceback.py

@@ -2157,6 +2157,31 @@ class BaseExceptionReportingTests:
         report = self.get_report(exc)
         self.assertEqual(report, expected)
 
+    def test_exception_group_wrapped_naked(self):
+        # See gh-128799
+
+        def exc():
+            try:
+                raise Exception(42)
+            except* Exception as e:
+                raise
+
+        expected = (f'  + Exception Group Traceback (most recent call last):\n'
+                    f'  |   File "{__file__}", line {self.callable_line}, in get_exception\n'
+                    f'  |     exception_or_callable()\n'
+                    f'  |   File "{__file__}", line {exc.__code__.co_firstlineno + 3}, in exc\n'
+                    f'  |     except* Exception as e:\n'
+                    f'  | ExceptionGroup:  (1 sub-exception)\n'
+                    f'  +-+---------------- 1 ----------------\n'
+                    f'    | Traceback (most recent call last):\n'
+                    f'    |   File "{__file__}", line {exc.__code__.co_firstlineno + 2}, in exc\n'
+                    f'    |     raise Exception(42)\n'
+                    f'    | Exception: 42\n'
+                    f'    +------------------------------------\n')
+
+        report = self.get_report(exc)
+        self.assertEqual(report, expected)
+
     def test_KeyboardInterrupt_at_first_line_of_frame(self):
         # see GH-93249
         def f():

Misc/NEWS.d/next/Core_and_Builtins/2025-01-18-01-06-58.gh-issue-128799.vSNagk.rst

@@ -0,0 +1 @@
+Add frame of ``except*`` to traceback when it wraps a naked exception.

Python/bytecodes.c

@@ -2114,7 +2114,7 @@ dummy_func(
 
             match = NULL;
             rest = NULL;
-            int res = exception_group_match(exc_value, match_type,
+            int res = exception_group_match(frame, exc_value, match_type,
                                             &match, &rest);
             DECREF_INPUTS();
             ERROR_IF(res < 0, error);

Python/ceval.c

@@ -20,6 +20,7 @@
 #include "pycore_range.h"         // _PyRangeIterObject
 #include "pycore_sliceobject.h"   // _PyBuildSlice_ConsumeRefs
 #include "pycore_sysmodule.h"     // _PySys_Audit()
+#include "pycore_traceback.h"     // _PyTraceBack_FromFrame
 #include "pycore_tuple.h"         // _PyTuple_ITEMS()
 #include "pycore_typeobject.h"    // _PySuper_Lookup()
 #include "pycore_emscripten_signal.h"  // _Py_CHECK_EMSCRIPTEN_SIGNALS
@@ -544,6 +545,7 @@ fail:
 
 static int do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause);
 static int exception_group_match(
+    _PyInterpreterFrame *frame,
     PyObject* exc_value, PyObject *match_type,
     PyObject **match, PyObject **rest);
 
@@ -1856,7 +1858,7 @@ raise_error:
 */
 
 static int
-exception_group_match(PyObject* exc_value, PyObject *match_type,
+exception_group_match(_PyInterpreterFrame *frame, PyObject* exc_value, PyObject *match_type,
                       PyObject **match, PyObject **rest)
 {
     if (Py_IsNone(exc_value)) {
@@ -1883,6 +1885,15 @@ exception_group_match(PyObject* exc_value, PyObject *match_type,
             if (wrapped == NULL) {
                 return -1;
             }
+            PyFrameObject *f = _PyFrame_GetFrameObject(frame);
+            if (f != NULL) {
+                PyObject *tb = _PyTraceBack_FromFrame(NULL, f);
+                if (tb == NULL) {
+                    return -1;
+                }
+                PyException_SetTraceback(wrapped, tb);
+                Py_DECREF(tb);
+            }
             *match = wrapped;
         }
         *rest = Py_NewRef(Py_None);

Python/generated_cases.c.h

@@ -2952,7 +2952,7 @@
 
             match = NULL;
             rest = NULL;
-            int res = exception_group_match(exc_value, match_type,
+            int res = exception_group_match(frame, exc_value, match_type,
                                             &match, &rest);
             #line 2958 "Python/generated_cases.c.h"
             Py_DECREF(exc_value);