after bug fix 5

Author: Sung-Min-Kim

src/main/java/org/apache/commons/csv/CSVPrinter.java

@@ -321,7 +321,10 @@ public void printComment(final String comment) throws IOException {
      *             If an I/O error occurs
      */
     public void println() throws IOException {
-        out.append(format.getRecordSeparator());
+        final String recordSeparator = format.getRecordSeparator();
+        if (recordSeparator != null) {
+            out.append(recordSeparator);
+        }
         newRecord = true;
     }
 

src/test/java/org/apache/commons/csv/CSVFormatTest.java

@@ -55,7 +55,7 @@ private static CSVFormat copy(final CSVFormat format) {
     public void testDelimiterSameAsCommentStartThrowsException() {
         CSVFormat.DEFAULT.withDelimiter('!').withCommentStart('!').validate();
     }
-
+    
     @Test(expected = IllegalStateException.class)
     public void testDelimiterSameAsEscapeThrowsException() {
         CSVFormat.DEFAULT.withDelimiter('!').withEscape('!').validate();
@@ -229,6 +229,14 @@ public void testGetHeader() throws Exception {
         assertNotSame(formatWithHeader.getHeader(), headerCopy);
     }
 
+    @Test
+    public void testNullRecordSeparatorCsv106() {
+        final CSVFormat format = CSVFormat.newFormat(';').withSkipHeaderRecord(true).withHeader("H1", "H2");
+        final String formatStr = format.format("A", "B");
+        assertNotNull(formatStr);
+        assertFalse(formatStr.endsWith("null"));
+    }
+
     @Test(expected = IllegalStateException.class)
     public void testQuoteCharSameAsCommentStartThrowsException() {
         CSVFormat.DEFAULT.withQuoteChar('!').withCommentStart('!').validate();