Factor out nsDef allocation into dom_alloc_ns_decl helper.

Author: devnexen

ext/dom/node.c

@@ -2103,65 +2103,71 @@ PHP_METHOD(DOMNode, lookupNamespaceURI)
 }
 /* }}} end dom_node_lookup_namespace_uri */
 
+/* Allocate, track and prepend a temporary nsDef entry for C14N.
+ * Returns the new xmlNsPtr for the caller to fill in href/prefix/_private,
+ * or NULL on allocation failure. */
+static xmlNsPtr dom_alloc_ns_decl(HashTable *links, xmlNodePtr node)
+{
+	xmlNsPtr ns = xmlMalloc(sizeof(*ns));
+	if (!ns) {
+		return NULL;
+	}
+
+	zval *zv = zend_hash_index_lookup(links, (zend_ulong) node);
+	if (Z_ISNULL_P(zv)) {
+		ZVAL_LONG(zv, 1);
+	} else {
+		Z_LVAL_P(zv)++;
+	}
+
+	memset(ns, 0, sizeof(*ns));
+	ns->type = XML_LOCAL_NAMESPACE;
+	ns->next = node->nsDef;
+	node->nsDef = ns;
+
+	return ns;
+}
+
 /* For DOM-built documents (e.g. createElementNS), namespaces live on node->ns
  * without corresponding xmlns attributes. C14N expects nsDef entries, so create
  * temporary ones. The _private field stays NULL to distinguish from attr-based
  * entries during cleanup. */
 static void dom_add_synthetic_ns_decl(HashTable *links, xmlNodePtr node, xmlNsPtr src_ns)
 {
+	/* Pre-existing nsDef entries are never filled in for Dom\XMLDocument.
+	 * This loop guards against duplicates from our own synthetic additions
+	 * within the same C14N pass (e.g. when an element and its attributes
+	 * share the same namespace prefix). */
 	for (xmlNsPtr existing = node->nsDef; existing; existing = existing->next) {
 		if (xmlStrEqual(existing->prefix, src_ns->prefix)) {
 			return;
 		}
 	}
 
-	xmlNsPtr ns = xmlMalloc(sizeof(*ns));
+	xmlNsPtr ns = dom_alloc_ns_decl(links, node);
 	if (!ns) {
 		return;
 	}
 
-	zval *zv = zend_hash_index_lookup(links, (zend_ulong) node);
-	if (Z_ISNULL_P(zv)) {
-		ZVAL_LONG(zv, 1);
-	} else {
-		Z_LVAL_P(zv)++;
-	}
-
-	memset(ns, 0, sizeof(*ns));
-	ns->type = XML_LOCAL_NAMESPACE;
 	ns->href = xmlStrdup(src_ns->href);
 	ns->prefix = src_ns->prefix ? xmlStrdup(src_ns->prefix) : NULL;
-	ns->next = node->nsDef;
-	node->nsDef = ns;
 }
 
 static void dom_relink_ns_decls_element(HashTable *links, xmlNodePtr node)
 {
 	if (node->type == XML_ELEMENT_NODE) {
 		for (xmlAttrPtr attr = node->properties; attr; attr = attr->next) {
 			if (php_dom_ns_is_fast((const xmlNode *) attr, php_dom_ns_is_xmlns_magic_token)) {
-				xmlNsPtr ns = xmlMalloc(sizeof(*ns));
+				xmlNsPtr ns = dom_alloc_ns_decl(links, node);
 				if (!ns) {
 					return;
 				}
 
-				zval *zv = zend_hash_index_lookup(links, (zend_ulong) node);
-				if (Z_ISNULL_P(zv)) {
-					ZVAL_LONG(zv, 1);
-				} else {
-					Z_LVAL_P(zv)++;
-				}
-
 				bool should_free;
 				xmlChar *attr_value = php_libxml_attr_value(attr, &should_free);
 
-				memset(ns, 0, sizeof(*ns));
-				ns->type = XML_LOCAL_NAMESPACE;
 				ns->href = should_free ? attr_value : xmlStrdup(attr_value);
 				ns->prefix = attr->ns->prefix ? xmlStrdup(attr->name) : NULL;
-				ns->next = node->nsDef;
-				node->nsDef = ns;
-
 				ns->_private = attr;
 				if (attr->prev) {
 					attr->prev = attr->next;