Raise TypeError for non-string hasattr.

This fixes #1702.

Cython/Compiler/Builtin.py

@@ -111,7 +111,7 @@ builtin_function_table = [
                         t.real_type, [
                             PyrexTypes.CFuncTypeArg("arg", t, None)
                             ],
-                            is_strict_signature = True, nogil=True)) 
+                            is_strict_signature = True, nogil=True))
                         for t in (PyrexTypes.c_float_complex_type,
                                   PyrexTypes.c_double_complex_type,
                                   PyrexTypes.c_longdouble_complex_type)
@@ -144,7 +144,8 @@ builtin_function_table = [
                     utility_code=getattr3_utility_code),
     BuiltinFunction('getattr',    "OO",   "O",     "__Pyx_GetAttr",
                     utility_code=getattr_utility_code),
-    BuiltinFunction('hasattr',    "OO",   "b",     "PyObject_HasAttr"),
+    BuiltinFunction('hasattr',    "OO",   "b",     "__Pyx_HasAttr",
+                    utility_code = UtilityCode.load("HasAttr", "Builtins.c")),
     BuiltinFunction('hash',       "O",    "h",     "PyObject_Hash"),
     #('hex',       "",     "",      ""),
     #('id',        "",     "",      ""),

Cython/Utility/Builtins.c

@@ -183,6 +183,30 @@ bad:
     return NULL;
 }
 
+//////////////////// HasAttr.proto ////////////////////
+
+static CYTHON_INLINE int __Pyx_HasAttr(PyObject *, PyObject *); /*proto*/
+
+//////////////////// HasAttr ////////////////////
+//@requires: ObjectHandling.c::GetAttr
+
+static CYTHON_INLINE int __Pyx_HasAttr(PyObject *o, PyObject *n) {
+    PyObject *r;
+    if (unlikely(!__Pyx_PyBaseString_Check(n))) {
+        PyErr_SetString(PyExc_TypeError,
+                        "hasattr(): attribute name must be string");
+        return -1;
+    }
+    r = __Pyx_GetAttr(o, n);
+    if (unlikely(!r)) {
+        PyErr_Clear();
+        return 0;
+    } else {
+        Py_DECREF(r);
+        return 1;
+    }
+}
+
 //////////////////// Intern.proto ////////////////////
 
 static PyObject* __Pyx_Intern(PyObject* s); /* proto */

tests/run/hasattr.pyx

@@ -17,6 +17,8 @@ def wrap_hasattr(obj, name):
     True
     >>> wrap_hasattr(Foo(), "foo")
     True
+    >>> wrap_hasattr(Foo(), u"foo")
+    True
     >>> wrap_hasattr(Foo(), "spam")
     False
     >>> wrap_hasattr(Foo(), "bar")
@@ -27,5 +29,9 @@ def wrap_hasattr(obj, name):
     ZeroDivisionError: ...
     >>> wrap_hasattr(Foo(), "baz")
     False
+    >>> hasattr(Foo(), None)   #doctest: +ELLIPSIS
+    Traceback (most recent call last):
+       ...
+    TypeError: hasattr(): attribute name must be string
     """
     return hasattr(obj, name)