Add commented out code for coercing start+end tags into null

Author: cowtowncoder

pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.fasterxml.jackson</groupId>
     <artifactId>jackson-base</artifactId>
-    <version>2.9.5</version>
+    <version>2.9.6-SNAPSHOT</version>
   </parent>
   <groupId>com.fasterxml.jackson.dataformat</groupId>
   <artifactId>jackson-dataformat-xml</artifactId>

src/main/java/com/fasterxml/jackson/dataformat/xml/deser/XmlTokenStream.java

@@ -381,9 +381,24 @@ private final String _collectUntilTag() throws XMLStreamException
         while (true) {
             switch (_xmlReader.next()) {
             case XMLStreamConstants.START_ELEMENT:
+                return (text == null) ? "" : text;
+
             case XMLStreamConstants.END_ELEMENT:
             case XMLStreamConstants.END_DOCUMENT:
+                // 04-May-2018, tatu: We could easily make <tag></tag> ALSO report
+                //    as `null`, by below, but that breaks existing tests so not
+                //    done at least until 3.0.
+                /*
+                if (text == null) {
+                    if (FromXmlParser.Feature.EMPTY_ELEMENT_AS_NULL.enabledIn(_formatFeatures)) {
+                        return null;
+                    }
+                    return "";
+                }
+                return text;
+                */
                 return (text == null) ? "" : text;
+                
             // note: SPACE is ignorable (and seldom seen), not to be included
             case XMLStreamConstants.CHARACTERS:
             case XMLStreamConstants.CDATA: