From cbbe4942e788ac3f3c74f966c1ff436dc06a38e2 Mon Sep 17 00:00:00 2001
From: Ilia Alshanetsky <ilia@ilia.ws>
Date: Mon, 24 Aug 2026 11:14:11 -0400
Subject: [PATCH] [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.
---
 NEWS                                          |  2 ++
 ext/simplexml/simplexml.c                     |  3 +-
 .../tests/attributes_dimension_write.phpt     | 30 +++++++++++++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 ext/simplexml/tests/attributes_dimension_write.phpt

diff --git a/NEWS b/NEWS
index a2c65685b4ce..c156668f14cf 100644
--- a/NEWS
+++ b/NEWS
@@ -120,6 +120,8 @@ PHP                                                                        NEWS
     corrupted). (ndossche)
 
 - SimpleXML:
+  . Fixed writing to a dimension of the object returned by attributes() not
+    creating the attribute. (iliaal)
   . Fixed integer element offsets that cannot resolve aliasing an existing
     element. (iliaal)
   . Fixed segfault when comparing uninitialized SimpleXMLElement
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"/>