Fix ticket #674.

2 files changed, 14 insertions, 2 deletions

diff --git a/numpy/core/src/arrayobject.c b/numpy/core/src/arrayobject.c
index 5b2390f03..fe789dee9 100644
--- a/numpy/core/src/arrayobject.c
+++ b/numpy/core/src/arrayobject.c
@@ -11145,7 +11145,8 @@ arraydescr_dealloc(PyArray_Descr *self)
 
 /* we need to be careful about setting attributes because these
    objects are pointed to by arrays that depend on them for interpreting
-   data.  Currently no attributes of dtype objects can be set.
+   data.  Currently no attributes of data-type objects can be set
+   directly except names.
 */
 static PyMemberDef arraydescr_members[] = {
     {"type", T_OBJECT, offsetof(PyArray_Descr, typeobj), RO, NULL},
@@ -11403,9 +11404,11 @@ arraydescr_names_set(PyArray_Descr *self, PyObject *val)
 	key = PyTuple_GET_ITEM(self->names, i);
 	/* Borrowed reference to item */
 	item = PyDict_GetItem(self->fields, key);
+	Py_INCREF(item); /* Hold on to it even through DelItem */
 	new_key = PyTuple_GET_ITEM(new_names, i);
-	PyDict_SetItem(self->fields, new_key, item);
 	PyDict_DelItem(self->fields, key);
+	PyDict_SetItem(self->fields, new_key, item);
+	Py_DECREF(item); /* self->fields now holds reference */
     }
 
     /* Replace names */
diff --git a/numpy/core/tests/test_regression.py b/numpy/core/tests/test_regression.py
index 33d12b61c..b104b888c 100644
--- a/numpy/core/tests/test_regression.py
+++ b/numpy/core/tests/test_regression.py
@@ -1174,6 +1174,15 @@ class TestRegression(TestCase):
         want = np.array([-1+0j, -1+0j, 0+0j, 1+0j, 1+0j, 0+0j])
         assert_equal(have, want)
 
+    def test_for_equal_names(self, level=rlevel):
+        """Ticket #674"""
+        dt = np.dtype([('foo', float), ('bar', float)])
+        a = np.zeros(10, dt)
+        b = list(a.dtype.names)
+        b[0] = "notfoo"
+        a.dtype.names = b
+        assert a.dtype.names[0] == "notfoo"
+        assert a.dtype.names[1] == "bar"
 
 if __name__ == "__main__":
     run_module_suite()