#7033: add new API function PyErr_NewExceptionWithDoc, for easily giving new exceptions a docstring.

Python/errors.c

@@ -604,6 +604,40 @@ PyErr_NewException(char *name, PyObject *base, PyObject *dict)
 	return result;
 }
 
+
+/* Create an exception with docstring */
+PyObject *
+PyErr_NewExceptionWithDoc(char *name, char *doc, PyObject *base, PyObject *dict)
+{
+	int result;
+	PyObject *ret = NULL;
+	PyObject *mydict = NULL; /* points to the dict only if we create it */
+	PyObject *docobj;
+
+	if (dict == NULL) {
+		dict = mydict = PyDict_New();
+		if (dict == NULL) {
+			return NULL;
+		}
+	}
+
+	if (doc != NULL) {
+		docobj = PyString_FromString(doc);
+		if (docobj == NULL)
+			goto failure;
+		result = PyDict_SetItemString(dict, "__doc__", docobj);
+		Py_DECREF(docobj);
+		if (result < 0)
+			goto failure;
+	}
+
+	ret = PyErr_NewException(name, base, dict);
+  failure:
+	Py_XDECREF(mydict);
+	return ret;
+}
+
+
 /* Call when an exception has occurred but there is no way for Python
    to handle it.  Examples: exception in __del__ or during GC. */
 void