Use SystemError for negative size

Use also UNINITIALIZED_SIZE in test code.

Author: vstinner

Lib/test/test_capi/test_tuple.py

@@ -77,9 +77,9 @@ def test_tuple_fromarray(self):
         copy = tuple_fromarray(NULL, 0)
         self.assertIs(copy, ())
 
-        with self.assertRaises(ValueError):
+        with self.assertRaises(SystemError):
             tuple_fromarray(NULL, -1)
-        with self.assertRaises(ValueError):
+        with self.assertRaises(SystemError):
             tuple_fromarray(NULL, PY_SSIZE_T_MIN)
         with self.assertRaises(MemoryError):
             tuple_fromarray(NULL, PY_SSIZE_T_MAX)

Modules/_testcapi/tuple.c

@@ -108,7 +108,7 @@ static PyObject *
 tuple_fromarray(PyObject* Py_UNUSED(module), PyObject *args)
 {
     PyObject *src;
-    Py_ssize_t size = -1;
+    Py_ssize_t size = UNINITIALIZED_SIZE;
     if (!PyArg_ParseTuple(args, "O|n", &src, &size)) {
         return NULL;
     }
@@ -120,7 +120,7 @@ tuple_fromarray(PyObject* Py_UNUSED(module), PyObject *args)
     PyObject **items;
     if (src != Py_None) {
         items = &PyTuple_GET_ITEM(src, 0);
-        if (size < 0) {
+        if (size == UNINITIALIZED_SIZE) {
             size = PyTuple_GET_SIZE(src);
         }
     }

Objects/tupleobject.c

@@ -371,10 +371,6 @@ PyTuple_FromArray(PyObject *const *src, Py_ssize_t n)
     if (n == 0) {
         return tuple_get_empty();
     }
-    if (n < 0) {
-        PyErr_SetString(PyExc_ValueError, "size must be nonnegative");
-        return NULL;
-    }
 
     PyTupleObject *tuple = tuple_alloc(n);
     if (tuple == NULL) {