[3.10] bpo-45083: Include the exception class qualname when formatting an exception (GH-28119) (GH-28134)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>
(cherry picked from commit b4b6342848ec0459182a992151099252434cc619)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>

* Use a private version of _PyType_GetQualName

Co-authored-by: Łukasz Langa <lukasz@langa.pl>

1 files changed, 17 insertions, 17 deletions

diff --git a/Python/errors.c b/Python/errors.c
index 9944c3a..600300e 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -3,6 +3,7 @@
 
 #include "Python.h"
 #include "pycore_initconfig.h"
+#include "pycore_object.h"        // _PyType_GetQualName
 #include "pycore_pyerrors.h"
 #include "pycore_pystate.h"    // _PyThreadState_GET()
 #include "pycore_sysmodule.h"
@@ -1323,46 +1324,45 @@ write_unraisable_exc_file(PyThreadState *tstate, PyObject *exc_type,
     }
 
     assert(PyExceptionClass_Check(exc_type));
-    const char *className = PyExceptionClass_Name(exc_type);
-    if (className != NULL) {
-        const char *dot = strrchr(className, '.');
-        if (dot != NULL) {
-            className = dot+1;
-        }
-    }
 
-    PyObject *moduleName = _PyObject_GetAttrId(exc_type, &PyId___module__);
-    if (moduleName == NULL || !PyUnicode_Check(moduleName)) {
-        Py_XDECREF(moduleName);
+    PyObject *modulename = _PyObject_GetAttrId(exc_type, &PyId___module__);
+    if (modulename == NULL || !PyUnicode_Check(modulename)) {
+        Py_XDECREF(modulename);
         _PyErr_Clear(tstate);
         if (PyFile_WriteString("<unknown>", file) < 0) {
             return -1;
         }
     }
     else {
-        if (!_PyUnicode_EqualToASCIIId(moduleName, &PyId_builtins)) {
-            if (PyFile_WriteObject(moduleName, file, Py_PRINT_RAW) < 0) {
-                Py_DECREF(moduleName);
+        if (!_PyUnicode_EqualToASCIIId(modulename, &PyId_builtins)) {
+            if (PyFile_WriteObject(modulename, file, Py_PRINT_RAW) < 0) {
+                Py_DECREF(modulename);
                 return -1;
             }
-            Py_DECREF(moduleName);
+            Py_DECREF(modulename);
             if (PyFile_WriteString(".", file) < 0) {
                 return -1;
             }
         }
         else {
-            Py_DECREF(moduleName);
+            Py_DECREF(modulename);
         }
     }
-    if (className == NULL) {
+
+    PyObject *qualname = _PyType_GetQualName((PyTypeObject *)exc_type);
+    if (qualname == NULL || !PyUnicode_Check(qualname)) {
+        Py_XDECREF(qualname);
+        _PyErr_Clear(tstate);
         if (PyFile_WriteString("<unknown>", file) < 0) {
             return -1;
         }
     }
     else {
-        if (PyFile_WriteString(className, file) < 0) {
+        if (PyFile_WriteObject(qualname, file, Py_PRINT_RAW) < 0) {
+            Py_DECREF(qualname);
             return -1;
         }
+        Py_DECREF(qualname);
     }
 
     if (exc_value && exc_value != Py_None) {