From 86b920ac931c9a78b067e08a84e3c587ec905047 Mon Sep 17 00:00:00 2001
From: Benoit Bovy <benbovy@gmail.com>
Date: Sun, 20 Mar 2022 22:10:03 +0100
Subject: [PATCH] reindex: fix missing variable metadata

---
 xarray/core/dataset.py       |  7 +++++++
 xarray/tests/test_dataset.py | 13 +++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index 155cf21b4db..093f2e5a58b 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -2543,6 +2543,13 @@ def _reindex_callback(
         new_variables = variables.copy()
         new_indexes = indexes.copy()
 
+        # re-assign variable metadata
+        for name, new_var in new_variables.items():
+            var = self._variables.get(name)
+            if var is not None:
+                new_var.attrs = var.attrs
+                new_var.encoding = var.encoding
+
         # pass through indexes from excluded dimensions
         # no extra check needed for multi-coordinate indexes, potential conflicts
         # should already have been detected when aligning the indexes
diff --git a/xarray/tests/test_dataset.py b/xarray/tests/test_dataset.py
index 96fa4ef144e..f37007a06e3 100644
--- a/xarray/tests/test_dataset.py
+++ b/xarray/tests/test_dataset.py
@@ -1878,6 +1878,19 @@ def test_reindex(self):
         actual = ds.reindex(x=[0, 1, 3], y=[0, 1])
         assert_identical(expected, actual)
 
+    def test_reindex_attrs_encoding(self):
+        ds = Dataset(
+            {"data": ("x", [1, 2, 3])},
+            {"x": ("x", [0, 1, 2], {"foo": "bar"}, {"bar": "baz"})},
+        )
+        actual = ds.reindex(x=[0, 1])
+        expected = Dataset(
+            {"data": ("x", [1, 2])},
+            {"x": ("x", [0, 1], {"foo": "bar"}, {"bar": "baz"})},
+        )
+        assert_identical(actual, expected)
+        assert actual.x.encoding == expected.x.encoding
+
     def test_reindex_warning(self):
         data = create_test_data()