bpo-29935: Fixed error messages in the index() method of tuple and list (#887) (#907) (#910)

when pass indices of wrong type.
(cherry picked from commit d4edfc9abffca965e76ebc5957a92031a4d6c4d4)
(cherry picked from commit bf4bb2e43030661e568d5d4b046e8b9351cc164c)
diff --git a/Include/ceval.h b/Include/ceval.h
index 3735f00..f461601 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -145,6 +145,7 @@
 #endif /* !WITH_THREAD */
 
 PyAPI_FUNC(int) _PyEval_SliceIndex(PyObject *, Py_ssize_t *);
+PyAPI_FUNC(int) _PyEval_SliceIndexNotNone(PyObject *, Py_ssize_t *);
 
 
 #ifdef __cplusplus
diff --git a/Misc/NEWS b/Misc/NEWS
index 8a07190..0ca08d6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- bpo-29935: Fixed error messages in the index() method of tuple and list
+  when pass indices of wrong type.
+
 - bpo-28598: Support __rmod__ for subclasses of str being called before
   str.__mod__.  Patch by Martijn Pieters.
 
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 8ee86c6..a71df7b 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2284,8 +2284,8 @@
     static PyObject *err_format = NULL;
 
     if (!PyArg_ParseTuple(args, "O|O&O&:index", &v,
-                                _PyEval_SliceIndex, &start,
-                                _PyEval_SliceIndex, &stop))
+                                _PyEval_SliceIndexNotNone, &start,
+                                _PyEval_SliceIndexNotNone, &stop))
         return NULL;
     if (start < 0) {
         start += Py_SIZE(self);
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 550719f..2495e95 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -515,8 +515,8 @@
     PyObject *v;
 
     if (!PyArg_ParseTuple(args, "O|O&O&:index", &v,
-                                _PyEval_SliceIndex, &start,
-                                _PyEval_SliceIndex, &stop))
+                                _PyEval_SliceIndexNotNone, &start,
+                                _PyEval_SliceIndexNotNone, &stop))
         return NULL;
     if (start < 0) {
         start += Py_SIZE(self);
diff --git a/Python/ceval.c b/Python/ceval.c
index 0983651..cea503e 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4689,7 +4689,7 @@
 int
 _PyEval_SliceIndex(PyObject *v, Py_ssize_t *pi)
 {
-    if (v != NULL) {
+    if (v != NULL && v != Py_None) {
         Py_ssize_t x;
         if (PyInt_Check(v)) {
             /* XXX(nnorwitz): I think PyInt_AS_LONG is correct,
@@ -4714,6 +4714,26 @@
     return 1;
 }
 
+int
+_PyEval_SliceIndexNotNone(PyObject *v, Py_ssize_t *pi)
+{
+    Py_ssize_t x;
+    if (PyIndex_Check(v)) {
+        x = PyNumber_AsSsize_t(v, NULL);
+        if (x == -1 && PyErr_Occurred())
+            return 0;
+    }
+    else {
+        PyErr_SetString(PyExc_TypeError,
+                        "slice indices must be integers or "
+                        "have an __index__ method");
+        return 0;
+    }
+    *pi = x;
+    return 1;
+}
+
+
 #undef ISINDEX
 #define ISINDEX(x) ((x) == NULL || \
                     PyInt_Check(x) || PyLong_Check(x) || PyIndex_Check(x))