[CSV-247] A single empty header is allowed when not allowing empty

column headers.

Add test case.

src/test/java/org/apache/commons/csv/issues/JiraCvs247Test.java

@@ -0,0 +1,64 @@
+/*
+ * 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.commons.csv.issues;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import java.io.Reader;
+import java.io.StringReader;
+import java.util.Arrays;
+import java.util.Iterator;
+
+import org.apache.commons.csv.CSVFormat;
+import org.apache.commons.csv.CSVParser;
+import org.apache.commons.csv.CSVRecord;
+import org.junit.jupiter.api.Test;
+
+public class JiraCvs247Test {
+
+    @Test
+    public void testHeadersMissingOneColumn() throws Exception {
+        final Reader in = new StringReader("a,,c,d,e\n1,2,3,4,5\nv,w,x,y,z");
+        try (final CSVParser parser = CSVFormat.DEFAULT.withHeader().parse(in)) {
+            assertEquals(Arrays.asList("a", "", "c", "d", "e"), parser.getHeaderNames());
+            final Iterator<CSVRecord> iterator = parser.iterator();
+            CSVRecord record = iterator.next();
+            assertEquals("1", record.get(0));
+            assertEquals("2", record.get(1));
+            assertEquals("3", record.get(2));
+            assertEquals("4", record.get(3));
+            assertEquals("5", record.get(4));
+            record = iterator.next();
+            assertEquals("v", record.get(0));
+            assertEquals("w", record.get(1));
+            assertEquals("x", record.get(2));
+            assertEquals("y", record.get(3));
+            assertEquals("z", record.get(4));
+            assertFalse(iterator.hasNext());
+        }
+    }
+
+    @Test
+    public void testJiraDescription() throws Exception {
+        final Reader in = new StringReader("a,,c,d\n1,2,3,4\nx,y,z,zz");
+        try (final CSVParser parser = CSVFormat.DEFAULT.withHeader().parse(in)) {
+            parser.iterator();
+        }
+    }
+
+}