From 414d730962f6a2ab0d5f31ef39a3e16b0d553cb3 Mon Sep 17 00:00:00 2001
From: Florian Schmaus <flo@geekplace.eu>
Date: Thu, 7 Jun 2018 17:15:16 +0200
Subject: [PATCH] Optimize XmlStringBuilder.element() for the empty element
 case

For example RSM (XEP-0059) gives <before/> a different semantic as
<before>UID</before>.
---
 .../java/org/jivesoftware/smack/util/XmlStringBuilder.java    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java b/smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java
index 0fdaceeb8..3f60077f4 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java
@@ -75,7 +75,9 @@ public class XmlStringBuilder implements Appendable, CharSequence, Element {
      * @return the XmlStringBuilder
      */
     public XmlStringBuilder element(String name, String content) {
-        assert content != null;
+        if (content.isEmpty()) {
+            return emptyElement(name);
+        }
         openElement(name);
         escape(content);
         closeElement(name);