From f04e5059bb3611f3fb373f7658f95b09fcee5ff3 Mon Sep 17 00:00:00 2001
From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
Date: Thu, 13 Jul 2023 13:34:45 +0200
Subject: [PATCH] Avoid allocations in DOMElement::getAttribute()

---
 ext/dom/element.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/ext/dom/element.c b/ext/dom/element.c
index 366341ede9f..e57871d3113 100644
--- a/ext/dom/element.c
+++ b/ext/dom/element.c
@@ -205,6 +205,7 @@ PHP_METHOD(DOMElement, getAttribute)
 	dom_object *intern;
 	xmlNodePtr attr;
 	size_t name_len;
+	bool should_free;
 
 	id = ZEND_THIS;
 	if (zend_parse_parameters(ZEND_NUM_ARGS(), "s", &name, &name_len) == FAILURE) {
@@ -218,12 +219,15 @@ PHP_METHOD(DOMElement, getAttribute)
 		switch (attr->type) {
 			case XML_ATTRIBUTE_NODE:
 				value = xmlNodeListGetString(attr->doc, attr->children, 1);
+				should_free = true;
 				break;
 			case XML_NAMESPACE_DECL:
-				value = xmlStrdup(((xmlNsPtr)attr)->href);
+				value = (xmlChar *) ((xmlNsPtr)attr)->href;
+				should_free = false;
 				break;
 			default:
-				value = xmlStrdup(((xmlAttributePtr)attr)->defaultValue);
+				value = (xmlChar *) ((xmlAttributePtr)attr)->defaultValue;
+				should_free = false;
 		}
 	}
 
@@ -231,7 +235,9 @@ PHP_METHOD(DOMElement, getAttribute)
 		RETURN_EMPTY_STRING();
 	} else {
 		RETVAL_STRING((char *)value);
-		xmlFree(value);
+		if (should_free) {
+			xmlFree(value);
+		}
 	}
 }
 /* }}} end dom_element_get_attribute */