From 692e5d5c88a939a7c3ce3de61c5fd39effe7c7ae Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Tue, 7 Aug 2018 11:37:58 +0200
Subject: [PATCH] Fix #76712: Assignment of empty string creates extraneous
 text node

We work around this peculiarity of libxml by using xmlNodeSetContent(),
which does not exhibit this behavior.  This also saves us from manually
calculating the string length.
---
 NEWS                              |  4 ++++
 ext/simplexml/simplexml.c         |  4 +---
 ext/simplexml/tests/bug76712.phpt | 24 ++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 ext/simplexml/tests/bug76712.phpt

diff --git a/NEWS b/NEWS
index 4aa88bffd5..bf8fe5b9af 100644
--- a/NEWS
+++ b/NEWS
@@ -24,6 +24,10 @@ PHP                                                                        NEWS
   . Fixed bug #76747 (Opcache treats path containing "test.pharma.tld" as a phar
     file). (Laruence)
 
+- SimpleXML:
+  . Fixed bug #76712 (Assignment of empty string creates extraneous text node).
+    (cmb)
+
 - SPL:
   . Fixed bug #68825 (Exception in DirectoryIterator::getLinkTarget()). (cmb)
   . Fixed bug #68175 (RegexIterator pregFlags are NULL instead of 0). (Tim
diff --git a/ext/simplexml/simplexml.c b/ext/simplexml/simplexml.c
index 92e6de107a..ab394b5c83 100644
--- a/ext/simplexml/simplexml.c
+++ b/ext/simplexml/simplexml.c
@@ -384,7 +384,6 @@ static zval *sxe_dimension_read(zval *object, zval *offset, int type, zval *rv)
 static void change_node_zval(xmlNodePtr node, zval *value)
 {
 	xmlChar *buffer;
-	int buffer_len;
 
 	if (!value)
 	{
@@ -401,10 +400,9 @@ static void change_node_zval(xmlNodePtr node, zval *value)
 			/* break missing intentionally */
 		case IS_STRING:
 			buffer = xmlEncodeEntitiesReentrant(node->doc, (xmlChar *)Z_STRVAL_P(value));
-			buffer_len = xmlStrlen(buffer);
 			/* check for NULL buffer in case of memory error in xmlEncodeEntitiesReentrant */
 			if (buffer) {
-				xmlNodeSetContentLen(node, buffer, buffer_len);
+				xmlNodeSetContent(node, buffer);
 				xmlFree(buffer);
 			}
 			break;
diff --git a/ext/simplexml/tests/bug76712.phpt b/ext/simplexml/tests/bug76712.phpt
new file mode 100644
index 0000000000..efd34b56e2
--- /dev/null
+++ b/ext/simplexml/tests/bug76712.phpt
@@ -0,0 +1,24 @@
+--TEST--
+BUg #76712 (Assignment of empty string creates extraneous text node)
+--SKIPIF--
+<?php
+if (!extension_loaded('simplexml')) die('skip simplexml not available');
+?>
+--FILE--
+<?php
+$sxe = new SimpleXMLElement('<foo></foo>');
+$sxe->addChild('bar', '');
+echo $sxe->asXML();
+
+$sxe = new SimpleXMLElement('<foo></foo>');
+$sxe->addChild('bar');
+$sxe->bar = '';
+echo $sxe->asXML();
+?>
+===DONE===
+--EXPECT--
+<?xml version="1.0"?>
+<foo><bar/></foo>
+<?xml version="1.0"?>
+<foo><bar/></foo>
+===DONE===
-- 
2.50.1