[CSV-169] The null string should be case-sensitive when reading records. Also simplify branch test.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/csv/trunk@1725358 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

src/changes/changes.xml

@@ -41,6 +41,7 @@
     <release version="1.3" date="2015-MM-DD" description="Feature and bug fix release">
       <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>
     </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/CSVParser.java

@@ -289,11 +289,7 @@ public CSVParser(final Reader reader, final CSVFormat format, final long charact
     private void addRecordValue() {
         final String input = this.reusableToken.content.toString();
         final String nullString = this.format.getNullString();
-        if (nullString == null) {
-            this.record.add(input);
-        } else {
-            this.record.add(input.equalsIgnoreCase(nullString) ? null : input);
-        }
+        this.record.add(input.equals(nullString) ? null : input);
     }
 
     /**