Issue #18519: the Python authorizer callback of sqlite3 must not raise Python exceptions

The exception is printed if sqlite3.enable_callback_tracebacks(True) has been
called, otherwise the exception is cleared.

Modules/_sqlite/connection.c

@@ -884,33 +884,32 @@ static int _authorizer_callback(void* user_arg, int action, const char* arg1, co
     gilstate = PyGILState_Ensure();
 #endif
 
-    if (!PyErr_Occurred()) {
     ret = PyObject_CallFunction((PyObject*)user_arg, "issss", action, arg1, arg2, dbname, access_attempt_source);
 
-        if (!ret) {
-            if (_enable_callback_tracebacks) {
+    if (ret == NULL) {
+        if (_enable_callback_tracebacks)
             PyErr_Print();
-            } else {
+        else
             PyErr_Clear();
-            }
 
         rc = SQLITE_DENY;
-        } else {
+    }
+    else {
         if (PyLong_Check(ret)) {
             rc = _PyLong_AsInt(ret);
-                if (rc == -1 && PyErr_Occurred())
-                    rc = SQLITE_DENY;
-            } else {
+            if (rc == -1 && PyErr_Occurred()) {
+                if (_enable_callback_tracebacks)
+                    PyErr_Print();
+                else
+                    PyErr_Clear();
                 rc = SQLITE_DENY;
             }
-            Py_DECREF(ret);
-        }
         }
         else {
-        /* A previous call to the authorizer callback failed and raised an
-           exception: don't call the Python authorizer callback */
             rc = SQLITE_DENY;
         }
+        Py_DECREF(ret);
+    }
 
 #ifdef WITH_THREAD
     PyGILState_Release(gilstate);