Signature: fix the __doc__ attribute of classes, amended

This additional change reverts the generation of AttributeError
and produces None, instead.

Change-Id: I9c9472cdd796b6686d5e7fb46a986ac4366098f2
Fixes: PYSIDE-1727
Pick-to: 6.2 5.15
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 15 insertions, 13 deletions

diff --git a/sources/shiboken6/libshiboken/signature/signature_extend.cpp b/sources/shiboken6/libshiboken/signature/signature_extend.cpp
index b31770048..a90f82910 100644
--- a/sources/shiboken6/libshiboken/signature/signature_extend.cpp
+++ b/sources/shiboken6/libshiboken/signature/signature_extend.cpp
@@ -163,19 +163,21 @@ static PyObject *handle_doc(PyObject *ob, PyObject *old_descr)
         name = PyModule_GetName(ob_type_mod.object());
     else
         name = reinterpret_cast<PyTypeObject *>(ob_type_mod.object())->tp_name;
-    if (handle_doc_in_progress || name == nullptr
-        || strncmp(name, "PySide6.", 8) != 0)
-        return PyObject_CallMethodObjArgs(old_descr,
-                                          PyMagicName::get(),
-                                          ob, nullptr);
-    handle_doc_in_progress++;
-    PyObject *res = PyObject_CallFunction(
-                        pyside_globals->make_helptext_func,
-                        "(O)", ob);
-    handle_doc_in_progress--;
-    if (res == nullptr)
-        PyErr_Format(PyExc_AttributeError, "%R object has no `__doc__` attribute", ob);
-    return res;
+    PyObject *res{};
+
+    if (handle_doc_in_progress || name == nullptr || strncmp(name, "PySide6.", 8) != 0) {
+        res = PyObject_CallMethodObjArgs(old_descr, PyMagicName::get(), ob, nullptr);
+    } else {
+        handle_doc_in_progress++;
+        res = PyObject_CallFunction(pyside_globals->make_helptext_func, "(O)", ob);
+        handle_doc_in_progress--;
+    }
+
+    if (res)
+        return res;
+
+    PyErr_Clear();
+    Py_RETURN_NONE;
 }
 
 static PyObject *pyside_cf_get___doc__(PyObject *cf)