Fixed incorrect error message constant for keyspace name length validation

patch by Yifan Cai; reviewed by Maxwell Guo, Stefan Miklosovic for CASSANDRA-20915

CHANGES.txt

@@ -1,4 +1,5 @@
 4.0.19
+ * Fixed incorrect error message constant for keyspace name length validation (CASSANDRA-20915)
  * update shaded cassandra-driver-core to 3.11.5 (CASSANDRA-20904)
  * Prevent too long table names not fitting file names (CASSANDRA-20389)
  * Fix IndexOutOfBoundsException in sstablemetadata tool when a range tombstone is a max clustering value (CASSANDRA-20855)

src/java/org/apache/cassandra/schema/KeyspaceMetadata.java

@@ -45,7 +45,6 @@ import org.apache.cassandra.service.StorageService;
 import static java.lang.String.format;
 
 import static com.google.common.collect.Iterables.any;
-import static org.apache.cassandra.schema.SchemaConstants.TABLE_NAME_LENGTH;
 
 /**
  * An immutable representation of keyspace metadata (name, params, tables, types, and functions).
@@ -66,7 +65,7 @@ public final class KeyspaceMetadata implements SchemaElement
                                                 keyspaceName));
         if (keyspaceName.length() > SchemaConstants.NAME_LENGTH)
             throw exceptionBuilder.apply(format("Keyspace name must not be more than %d characters long (got %d characters for \"%s\")",
-                                                TABLE_NAME_LENGTH, keyspaceName.length(), keyspaceName));
+                                                SchemaConstants.NAME_LENGTH, keyspaceName.length(), keyspaceName));
     }
 
     public enum Kind

test/unit/org/apache/cassandra/schema/KeyspaceMetadataTest.java

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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.apache.cassandra.schema;
+
+import org.junit.Test;
+
+import org.apache.cassandra.exceptions.ConfigurationException;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class KeyspaceMetadataTest
+{
+    @Test
+    public void testValidateKeyspaceNameTooLongShowsCorrectLimit()
+    {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < SchemaConstants.NAME_LENGTH + 1; i++)
+            sb.append('a');
+
+        String longKeyspaceName = sb.toString();
+        String expectedMessage = String.format("Keyspace name must not be more than %d characters long (got %d characters for \"%s\")",
+                                               SchemaConstants.NAME_LENGTH,
+                                               longKeyspaceName.length(),
+                                               longKeyspaceName);
+
+        assertThatThrownBy(() -> KeyspaceMetadata.validateKeyspaceName(longKeyspaceName, ConfigurationException::new))
+        .isInstanceOf(ConfigurationException.class)
+        .hasMessage(expectedMessage);
+    }
+}