Better isinstance error message.

Closes SF patch # 560250.

Bugfix candidate IMO.

diff --git a/Objects/abstract.c b/Objects/abstract.c
index d10d9d4b0ca2217d71969d38f780e7cac4bcc361..917195a200bcdfe1e470ac183059ebb6c15751f2 100644 (file)
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1976,7 +1976,8 @@ PyObject_IsInstance(PyObject *inst, PyObject *cls)
                        /* Do not mask errors. */
                        if (!PyErr_Occurred())
                                PyErr_SetString(PyExc_TypeError,
-                               "isinstance() arg 2 must be a class or type");
+                               "isinstance() arg 2 must be a class, type,"
+                               " or tuple of classes and types");
                        return -1;
                }
                Py_DECREF(cls_bases);