BUG: retain writeable flag when indexing subclasses

juliantaylor · juliantaylor · commit 77d62bb551c1 · 2014-07-06T18:07:05.000+02:00
diff --git a/numpy/core/src/multiarray/mapping.c b/numpy/core/src/multiarray/mapping.c
@@ -1058,6 +1058,9 @@ array_boolean_subscript(PyArrayObject *self,
             Py_DECREF(ret);
             return NULL;
         }
+        if (_IsWriteable(ret)) {
+            PyArray_ENABLEFLAGS(ret, NPY_ARRAY_WRITEABLE);
+        }
     }
 
     return ret;
@@ -1583,6 +1586,9 @@ array_subscript(PyArrayObject *self, PyObject *op)
             result = NULL;
             goto finish;
         }
+        if (_IsWriteable(result)) {
+            PyArray_ENABLEFLAGS(result, NPY_ARRAY_WRITEABLE);
+        }
     }
 
   finish:
diff --git a/numpy/core/tests/test_indexing.py b/numpy/core/tests/test_indexing.py
@@ -285,6 +285,17 @@ def __array_finalize__(self, old):
         assert_((a == 1).all())
 
 
+    def test_subclass_writeable(self):
+        d = np.rec.array([('NGC1001', 11), ('NGC1002', 1.), ('NGC1003', 1.)],
+                         dtype=[('target', 'S20'), ('V_mag', '>f4')])
+        ind = np.array([False,  True,  True], dtype=bool)
+        assert_(d[ind].flags.writeable)
+        ind = np.array([0, 1])
+        assert_(d[ind].flags.writeable)
+        assert_(d[...].flags.writeable)
+        assert_(d[0].flags.writeable)
+
+
     def test_memory_order(self):
         # This is not necessary to preserve. Memory layouts for
         # more complex indices are not as simple.

Original file line number	Diff line number	Diff line change
`@@ -1058,6 +1058,9 @@ array_boolean_subscript(PyArrayObject *self,`
`1058`	`1058`	`Py_DECREF(ret);`
`1059`	`1059`	`return NULL;`
`1060`	`1060`	`}`
	`1061`	`+ if (_IsWriteable(ret)) {`
	`1062`	`+ PyArray_ENABLEFLAGS(ret, NPY_ARRAY_WRITEABLE);`
	`1063`	`+ }`
`1061`	`1064`	`}`
`1062`	`1065`
`1063`	`1066`	`return ret;`
`@@ -1583,6 +1586,9 @@ array_subscript(PyArrayObject self, PyObject op)`
`1583`	`1586`	`result = NULL;`
`1584`	`1587`	`goto finish;`
`1585`	`1588`	`}`
	`1589`	`+ if (_IsWriteable(result)) {`
	`1590`	`+ PyArray_ENABLEFLAGS(result, NPY_ARRAY_WRITEABLE);`
	`1591`	`+ }`
`1586`	`1592`	`}`
`1587`	`1593`
`1588`	`1594`	`finish:`