Merge branch '5.x' into 5.6

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Fixed a JavaScript error that could occur on element edit pages. ([#16055](https://github.com/craftcms/cms/issues/16055))
 - Fixed a Twig deprecation error. ([#16107](https://github.com/craftcms/cms/issues/16107))
+- Fixed a bug where `craft\services\Structures::fillGapsInElements()` wasn’t working properly if the elements weren’t passed in hierarchical order. ([#16085](https://github.com/craftcms/cms/issues/16085))
 - Fixed a bug where `craft\helpers\Console::table()` wasn’t handling multi-byte characters and ANSI-formatted strings properly.
 - Fixed a bug where entries could appear to retain old field values when switching entry types, even if the new type’s fields weret’t compatible with the original type’s fields. ([#16056](https://github.com/craftcms/cms/issues/16056))
 - Fixed a bug where Link field query params weren’t working for elements that hadn’t been saved since updating to Craft 5.5.0+. ([#16113](https://github.com/craftcms/cms/issues/16113))

src/services/Structures.php

@@ -155,6 +155,10 @@ public function fillGapsInElements(array &$elements): void
         $prevElement = null;
         $patchedElements = [];
 
+        // https://github.com/craftcms/cms/issues/16085
+        // don't assume that elements are in the top to bottom order
+        usort($elements, fn(ElementInterface $a, ElementInterface $b) => $a->lft <=> $b->lft);
+
         foreach ($elements as $i => $element) {
             // Did we just skip any elements?
             if (