--- old/src/java.xml/share/classes/com/sun/org/apache/xml/internal/serializer/output_html.properties	2016-12-15 18:42:11.506623301 +0800
+++ new/src/java.xml/share/classes/com/sun/org/apache/xml/internal/serializer/output_html.properties	2016-12-15 18:42:11.384684301 +0800
@@ -39,7 +39,7 @@
 #              xalan:content-handler="MyContentHandler"/>
 #  ...
 # Note that the colon after the protocol needs to be escaped.
-{http\u003a//xml.apache.org/xalan}indent-amount=0
+{http\u003a//xml.apache.org/xalan}indent-amount=4
 {http\u003a//xml.apache.org/xalan}content-handler=com.sun.org.apache.xml.internal.serializer.ToHTMLStream
 {http\u003a//xml.apache.org/xalan}entities=com/sun/org/apache/xml/internal/serializer/HTMLEntities
 {http\u003a//xml.apache.org/xalan}use-url-escaping=yes