more correct fake implementation of PyNumber_Index() and PyIndex_Check() for Py2.4

Cython/Utility/ModuleSetupCode.c

@@ -47,8 +47,11 @@
   #define PY_FORMAT_SIZE_T ""
   #define PyInt_FromSsize_t(z) PyInt_FromLong(z)
   #define PyInt_AsSsize_t(o)   __Pyx_PyInt_AsInt(o)
-  #define PyNumber_Index(o)    PyNumber_Int(o)
-  #define PyIndex_Check(o)     PyNumber_Check(o)
+  #define PyNumber_Index(o)    ((PyNumber_Check(o) && !PyFloat_Check(o)) ? \
+                                PyNumber_Int(o) \
+                                : (PyErr_Format(PyExc_TypeError, "expected index value, got %.200s", \
+                                                Py_TYPE(o)->tp_name), NULL))
+  #define PyIndex_Check(o)     (PyNumber_Check(o) && !PyFloat_Check(o) && !PyComplex_Check(o))
   #define PyErr_WarnEx(category, message, stacklevel) PyErr_Warn(category, message)
   #define __PYX_BUILD_PY_SSIZE_T "i"
 #else

tests/run/unportable_capi_functions.pyx

+# mode: run
+# tag: portability
+
+# test some C-API functions that Cython replaces for portability reasons
+
+from cpython.number cimport PyNumber_Index, PyIndex_Check
+
+def number_index(x):
+    """
+    >>> number_index(1)
+    1
+    >>> try: number_index(1.1)
+    ... except TypeError: pass
+    ... else: print "FAILED"
+    >>> try: number_index(1j)
+    ... except TypeError: pass
+    ... else: print "FAILED"
+    >>> try: number_index('abc')
+    ... except TypeError: pass
+    ... else: print "FAILED"
+    """
+    # was not available in Py2.4
+    return PyNumber_Index(x)
+
+def index_check(x):
+    """
+    >>> index_check(1)
+    True
+    >>> index_check(1.1)
+    False
+    >>> index_check(1j)
+    False
+    >>> index_check('abc')
+    False
+    """
+    # was not available in Py2.4
+    return PyIndex_Check(x)