[CSV-168] CsvFormat.nullString should not be escaped. [CSV-170]

CSVFormat.MYSQL nullString should be "\N".

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/csv/trunk@1725407 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

src/changes/changes.xml

@@ -42,6 +42,8 @@
       <action issue="CSV-153" type="update" dev="britter" due-to="Wren">CSVPrinter doesn't skip creation of header record if skipHeaderRecord is set to true</action>
       <action issue="CSV-159" type="add" dev="ggregory" due-to="Yamil Medina">Add IgnoreCase option for accessing header names</action>
       <action issue="CSV-169" type="add" dev="ggregory" due-to="Gary Gregory">The null string should be case-sensitive when reading records</action>
+      <action issue="CSV-168" type="fix" dev="ggregory" due-to="Gary Gregory, cornel creanga">CsvFormat.nullString should not be escaped</action>
+      <action issue="CSV-170" type="fix" dev="ggregory" due-to="Gary Gregory, cornel creanga">CSVFormat.MYSQL nullString should be "\N"</action>
     </release>
     <release version="1.2" date="2015-08-24" description="Feature and bug fix release">
       <action issue="CSV-145" type="fix" dev="ggregory" due-to="Frank Ulbricht">CSVFormat.with* methods clear the header comments</action>

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

@@ -296,7 +296,7 @@ public CSVFormat getFormat() {
      *
      * <p>
      * This is a tab-delimited format with a LF character as the line separator. Values are not quoted and special
-     * characters are escaped with '\'.
+     * characters are escaped with {@code '\'}. The default NULL string is {@code "\\N"}.
      * </p>
      *
      * <p>
@@ -308,14 +308,15 @@ public CSVFormat getFormat() {
      * <li>withRecordSeparator('\n')</li>
      * <li>withIgnoreEmptyLines(false)</li>
      * <li>withEscape('\\')</li>
+     * <li>withNullString("\\N")</li>
      * </ul>
      *
      * @see Predefined#MySQL
      * @see <a href="http://dev.mysql.com/doc/refman/5.1/en/load-data.html">
      *      http://dev.mysql.com/doc/refman/5.1/en/load-data.html</a>
      */
     public static final CSVFormat MYSQL = DEFAULT.withDelimiter(TAB).withEscape(BACKSLASH).withIgnoreEmptyLines(false)
-            .withQuote(null).withRecordSeparator(LF);
+            .withQuote(null).withRecordSeparator(LF).withNullString("\\N");
 
     /**
      * Returns true if the given character is a line break character.

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

@@ -136,7 +136,9 @@ private void print(final Object object, final CharSequence value, final int offs
         if (!newRecord) {
             out.append(format.getDelimiter());
         }
-        if (format.isQuoteCharacterSet()) {
+        if (object == null) {
+            out.append(value);
+        } else if (format.isQuoteCharacterSet()) {
             // the original object is needed so can check for Number
             printAndQuote(object, value, offset, len);
         } else if (format.isEscapeCharacterSet()) {