Shard Allocation: `index.routing.allocation....` settings do not "remove" the setting on empty string, closes #2229.

src/main/java/org/elasticsearch/cluster/node/DiscoveryNodeFilters.java

@@ -41,7 +41,10 @@ public class DiscoveryNodeFilters {
     public static DiscoveryNodeFilters buildFromKeyValue(Map<String, String> filters) {
         Map<String, String[]> bFilters = new HashMap<String, String[]>();
         for (Map.Entry<String, String> entry : filters.entrySet()) {
-            bFilters.put(entry.getKey(), Strings.splitStringByCommaToArray(entry.getValue()));
+            String[] values = Strings.splitStringByCommaToArray(entry.getValue());
+            if (values.length > 0) {
+                bFilters.put(entry.getKey(), values);
+            }
         }
         if (bFilters.isEmpty()) {
             return NO_FILTERS;

src/test/java/org/elasticsearch/test/unit/cluster/node/DiscoveryNodeFiltersTests.java

@@ -0,0 +1,76 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. ElasticSearch licenses this
+ * file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.test.unit.cluster.node;
+
+import com.google.common.collect.ImmutableMap;
+import org.elasticsearch.cluster.node.DiscoveryNode;
+import org.elasticsearch.cluster.node.DiscoveryNodeFilters;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.transport.DummyTransportAddress;
+import org.testng.annotations.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+/**
+ */
+@Test
+public class DiscoveryNodeFiltersTests {
+
+    @Test
+    public void nameMatch() {
+        Settings settings = ImmutableSettings.settingsBuilder()
+                .put("xxx.name", "name1")
+                .build();
+        DiscoveryNodeFilters filters = DiscoveryNodeFilters.buildFromSettings("xxx.", settings);
+
+        DiscoveryNode node = new DiscoveryNode("name1", "id1", DummyTransportAddress.INSTANCE, ImmutableMap.<String, String>of());
+        assertThat(filters.match(node), equalTo(true));
+
+        node = new DiscoveryNode("name2", "id2", DummyTransportAddress.INSTANCE, ImmutableMap.<String, String>of());
+        assertThat(filters.match(node), equalTo(false));
+    }
+
+    @Test
+    public void idMatch() {
+        Settings settings = ImmutableSettings.settingsBuilder()
+                .put("xxx._id", "id1")
+                .build();
+        DiscoveryNodeFilters filters = DiscoveryNodeFilters.buildFromSettings("xxx.", settings);
+
+        DiscoveryNode node = new DiscoveryNode("name1", "id1", DummyTransportAddress.INSTANCE, ImmutableMap.<String, String>of());
+        assertThat(filters.match(node), equalTo(true));
+
+        node = new DiscoveryNode("name2", "id2", DummyTransportAddress.INSTANCE, ImmutableMap.<String, String>of());
+        assertThat(filters.match(node), equalTo(false));
+    }
+
+    @Test
+    public void emptyString() {
+        Settings settings = ImmutableSettings.settingsBuilder()
+                .put("xxx.name", "")
+                .build();
+        DiscoveryNodeFilters filters = DiscoveryNodeFilters.buildFromSettings("xxx.", settings);
+
+        DiscoveryNode node = new DiscoveryNode("name1", "id1", DummyTransportAddress.INSTANCE, ImmutableMap.<String, String>of());
+        assertThat(filters.match(node), equalTo(true));
+    }
+}