[php-src] master: [SimpleXML] Fix creating new attributes via attributes() dimension write

Author: Ilia Alshanetsky (iliaal)
Date: 2026-08-30T11:03:49-04:00

Commit: https://github.com/php/php-src/commit/fc7a6b900704fd7710cc1027f82a3670123430e5
Raw diff: https://github.com/php/php-src/commit/fc7a6b900704fd7710cc1027f82a3670123430e5.diff

[SimpleXML] Fix creating new attributes via attributes() dimension write

sxe_prop_dim_write() overwrote the element node with the first attribute
node when resolving an SXE_ITER_ATTRLIST iterator, so xmlNewProp() targeted
a non-element node and was skipped entirely when no attribute existed yet.
Keep the element node in place and resolve only the attribute list start,
so $x->attributes()["new"] = "v" creates the attribute like the symmetric
$x["new"] path; property writes on the attributes() object share the fixed
path while read/exists/unset handlers are unaffected by this defect.

Closes GH-23500

Changed paths:
  A  ext/simplexml/tests/attributes_dimension_write.phpt
  M  NEWS
  M  ext/simplexml/simplexml.c


Diff:

diff --git a/NEWS b/NEWS
index db1aba15a8e6..546364fbc2ca 100644
--- a/NEWS
+++ b/NEWS
@@ -75,6 +75,10 @@ PHP                                                                        NEWS
     an object converted to an array fails. (David Carlier)
   . Fixed read buffer compaction in php_stream_filter_flush(). (crystarm)
 
+- SimpleXML:
+  . Fixed writing to a dimension of the object returned by attributes() not
+    creating the attribute. (Ilia Alshanetsky)
+
 - Zip:
   . Fixed bug GH-23276 (ZipArchive subclass storing its own stream cannot be
     garbage collected). (Weilin Du, ndossche)
diff --git a/ext/simplexml/simplexml.c b/ext/simplexml/simplexml.c
index 1a346200199b..44fdef5e12d7 100644
--- a/ext/simplexml/simplexml.c
+++ b/ext/simplexml/simplexml.c
@@ -443,8 +443,7 @@ static zval *sxe_prop_dim_write(zend_object *object, zval *member, zval *value,
 	if (sxe->iter.type == SXE_ITER_ATTRLIST) {
 		attribs = 1;
 		elements = 0;
-		node = php_sxe_get_first_node_non_destructive(sxe, node);
-		attr = (xmlAttrPtr)node;
+		attr = (xmlAttrPtr)php_sxe_get_first_node_non_destructive(sxe, node);
 		test = sxe->iter.name != NULL;
 	} else if (sxe->iter.type != SXE_ITER_CHILD) {
 		mynode = node;
diff --git a/ext/simplexml/tests/attributes_dimension_write.phpt b/ext/simplexml/tests/attributes_dimension_write.phpt
new file mode 100644
index 000000000000..8721dc7dc7c2
--- /dev/null
+++ b/ext/simplexml/tests/attributes_dimension_write.phpt
@@ -0,0 +1,30 @@
+--TEST--
+Creating new attributes via dimension and property writes on attributes()
+--FILE--
+<?php
+$x = simplexml_load_string('<r a="1"/>');
+$x->attributes()['new'] = 'v';
+echo $x->asXML();
+
+$a = simplexml_load_string('<r/>');
+$a->attributes()['created'] = 'yes';
+echo $a->asXML();
+
+$b = simplexml_load_string('<r a="1"/>');
+$attrs = $b->attributes();
+$attrs->other = 2;
+echo $b->asXML();
+
+$c = simplexml_load_string('<r a="1"/>');
+$c->attributes()['a'] = '2';
+echo $c->asXML();
+?>
+--EXPECT--
+<?xml version="1.0"?>
+<r a="1" new="v"/>
+<?xml version="1.0"?>
+<r created="yes"/>
+<?xml version="1.0"?>
+<r a="1" other="2"/>
+<?xml version="1.0"?>
+<r a="2"/>