From 15259a0a6c86e78001cff8cd8d73d8892bfa6bfb Mon Sep 17 00:00:00 2001
From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
Date: Tue, 2 Apr 2024 23:29:52 +0200
Subject: [PATCH] Factor out common "first container's child" code

---
 ext/dom/dom_iterators.c | 13 ++-----------
 ext/dom/nodelist.c      | 12 ++----------
 ext/dom/php_dom.h       | 10 ++++++++++
 3 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/ext/dom/dom_iterators.c b/ext/dom/dom_iterators.c
index 8efadf9b156..06674472d7b 100644
--- a/ext/dom/dom_iterators.c
+++ b/ext/dom/dom_iterators.c
@@ -180,11 +180,7 @@ static void php_dom_iterator_move_forward(zend_object_iterator *iter) /* {{{ */
 					if (php_dom_is_cache_tag_stale_from_node(&iterator->cache_tag, basenode)) {
 						php_dom_mark_cache_tag_up_to_date_from_node(&iterator->cache_tag, basenode);
 						previndex = 0;
-						if (basenode->type == XML_DOCUMENT_NODE || basenode->type == XML_HTML_DOCUMENT_NODE) {
-							curnode = xmlDocGetRootElement((xmlDoc *) basenode);
-						} else {
-							curnode = basenode->children;
-						}
+						curnode = php_dom_first_child_of_container_node(basenode);
 					} else {
 						previndex = iter->index - 1;
 						curnode = (xmlNodePtr)((php_libxml_node_ptr *)intern->ptr)->node;
@@ -264,12 +260,7 @@ zend_object_iterator *php_dom_get_iterator(zend_class_entry *ce, zval *object, i
 						curnode = (xmlNodePtr) basep->children;
 					}
 				} else {
-					xmlNodePtr nodep = basep;
-					if (nodep->type == XML_DOCUMENT_NODE || nodep->type == XML_HTML_DOCUMENT_NODE) {
-						nodep = xmlDocGetRootElement((xmlDoc *) nodep);
-					} else {
-						nodep = nodep->children;
-					}
+					xmlNodePtr nodep = php_dom_first_child_of_container_node(basep);
 					curnode = dom_get_elements_by_tag_name_ns_raw(
 						basep, nodep, objmap->ns, objmap->local, objmap->local_lower, &curindex, 0);
 				}
diff --git a/ext/dom/nodelist.c b/ext/dom/nodelist.c
index a178b110dc7..0a0ab32e5c2 100644
--- a/ext/dom/nodelist.c
+++ b/ext/dom/nodelist.c
@@ -93,11 +93,7 @@ int php_dom_get_nodelist_length(dom_object *obj)
 		}
 	} else {
 		xmlNodePtr basep = nodep;
-		if (nodep->type == XML_DOCUMENT_NODE || nodep->type == XML_HTML_DOCUMENT_NODE) {
-			nodep = xmlDocGetRootElement((xmlDoc *) nodep);
-		} else {
-			nodep = nodep->children;
-		}
+		nodep = php_dom_first_child_of_container_node(basep);
 		dom_get_elements_by_tag_name_ns_raw(
 			basep, nodep, objmap->ns, objmap->local, objmap->local_lower, &count, INT_MAX - 1 /* because of <= */);
 	}
@@ -189,11 +185,7 @@ void php_dom_nodelist_get_item_into_zval(dom_nnodemap_object *objmap, zend_long
 							itemnode = nodep;
 						} else {
 							if (restart) {
-								if (basep->type == XML_DOCUMENT_NODE || basep->type == XML_HTML_DOCUMENT_NODE) {
-									nodep = xmlDocGetRootElement((xmlDoc*) basep);
-								} else {
-									nodep = basep->children;
-								}
+								nodep = php_dom_first_child_of_container_node(basep);
 							}
 							itemnode = dom_get_elements_by_tag_name_ns_raw(basep, nodep, objmap->ns, objmap->local, objmap->local_lower, &count, relative_index);
 						}
diff --git a/ext/dom/php_dom.h b/ext/dom/php_dom.h
index 9a5bdcbe663..e64695f07b1 100644
--- a/ext/dom/php_dom.h
+++ b/ext/dom/php_dom.h
@@ -275,6 +275,16 @@ static zend_always_inline bool php_dom_follow_spec_node(const xmlNode *node)
 	return false;
 }
 
+/* Returns the first child of a container node (e.g. elements, fragments, documents, ...). */
+static zend_always_inline xmlNodePtr php_dom_first_child_of_container_node(xmlNodePtr parent)
+{
+	if (parent->type == XML_DOCUMENT_NODE || parent->type == XML_HTML_DOCUMENT_NODE) {
+		return xmlDocGetRootElement((xmlDoc *) parent);
+	} else {
+		return parent->children;
+	}
+}
+
 PHP_MINIT_FUNCTION(dom);
 PHP_MSHUTDOWN_FUNCTION(dom);
 PHP_MINFO_FUNCTION(dom);