Fix indexing error for data loaded with open_rasterio (pydata#2456)

xref GH2454

doc/whats-new.rst

@@ -76,6 +76,10 @@ Bug fixes
   By `Deepak Cherian <https://github.com/dcherian>`_.
 
 
+- Fix a bug that caused some indexing operations on arrays opened with
+  ``open_rasterio`` to error (:issue:`2454`).
+  By `Stephan Hoyer <https://github.com/shoyer>`_.
+
 .. _whats-new.0.10.9:
 
 v0.10.9 (21 September 2018)
@@ -86,7 +90,7 @@ This minor release contains a number of backwards compatible enhancements.
 Announcements of note:
 
 - Xarray is now a NumFOCUS fiscally sponsored project! Read
-  `the anouncment <https://numfocus.org/blog/xarray-joins-numfocus-sponsored-projects>`_
+  `the anouncement <https://numfocus.org/blog/xarray-joins-numfocus-sponsored-projects>`_
   for more details.
 - We have a new :doc:`roadmap` that outlines our future development plans.
 

xarray/backends/rasterio_.py

@@ -95,7 +95,7 @@ def _get_indexer(self, key):
 
         if isinstance(key[1], np.ndarray) and isinstance(key[2], np.ndarray):
             # do outer-style indexing
-            np_inds[1:] = np.ix_(*np_inds[1:])
+            np_inds[-2:] = np.ix_(*np_inds[-2:])
 
         return band_key, tuple(window), tuple(squeeze_axis), tuple(np_inds)
 

xarray/tests/test_backends.py

@@ -2925,6 +2925,10 @@ def test_indexing(self):
                 assert_allclose(expected.isel(**ind), actual.isel(**ind))
                 assert not actual.variable._in_memory
 
+                ind = {'band': 0, 'x': np.array([0, 0]), 'y': np.array([1, 1, 1])}
+                assert_allclose(expected.isel(**ind), actual.isel(**ind))
+                assert not actual.variable._in_memory
+
                 # minus-stepped slice
                 ind = {'band': np.array([2, 1, 0]),
                        'x': slice(-1, None, -1), 'y': 0}