Bugfix/505 propagate value

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Fixed an error that could occur when creating a nested entry. ([#505](https://github.com/craftcms/ckeditor/issues/505))
 - Fixed a bug where `&nbps;` briefly appeared below the editor on page load, if the “Show word count” setting was enabled. ([#507](https://github.com/craftcms/ckeditor/issues/507))
 
 ## 4.11.1 - 2026-02-18

src/Field.php

@@ -11,6 +11,7 @@
 use craft\base\CrossSiteCopyableFieldInterface;
 use craft\base\ElementContainerFieldInterface;
 use craft\base\ElementInterface;
+use craft\base\Event;
 use craft\base\FieldInterface;
 use craft\base\MergeableFieldInterface;
 use craft\base\NestedElementInterface;
@@ -38,6 +39,7 @@
 use craft\enums\PropagationMethod;
 use craft\errors\InvalidHtmlTagException;
 use craft\events\CancelableEvent;
+use craft\events\DraftEvent;
 use craft\events\DuplicateNestedElementsEvent;
 use craft\helpers\ArrayHelper;
 use craft\helpers\Cp;
@@ -56,6 +58,7 @@
 use craft\models\ImageTransform;
 use craft\models\Section;
 use craft\models\Volume;
+use craft\services\Drafts;
 use craft\services\ElementSources;
 use craft\web\View;
 use GraphQL\Type\Definition\Type;
@@ -1914,14 +1917,31 @@ public function setEnableSourceEditingForNonAdmins(bool $value): void
      */
     public function propagateValue(ElementInterface $from, ElementInterface $to): void
     {
+        $wasValueEmpty = $this->isValueEmpty($to->getFieldValue($this->handle), $to);
+
         /** @phpstan-ignore-next-line */
         parent::propagateValue($from, $to);
 
-        if (!$from->propagateAll) {
+        if (!$from->propagateAll && $wasValueEmpty) {
             // NestedElementManager won't duplicate the nested entries automatically,
             // because the field has a value in the target site (the HTML content), so isValueEmpty() is false.
             /** @phpstan-ignore-next-line */
             self::entryManager($this)->duplicateNestedElements($from, $to, force: true);
         }
+
+        // when the field is translatable (e.g. for each site);
+        // you create a new entry and add nested entry into a cke field while the entry is fresh
+        // during autosave, that nested entry gets duplicated into the other site correctly (along with value adjustment)
+        // however when you then fully save the owner,
+        // the duplication is triggered twice - from ElementsController::actionApplyDraft() and from Drafts::removeDraftData()
+        // the changes in 5.9.0 mean that the nested entries get duplicated and adjusted twice
+        // (via NEM::saveNestedElements > duplicateNestedElements() route)
+        // causing the nested entry in the site we propagated to, to have a wrong ID
+        // the CKE content references X, but X nested entry is marked as deleted and Y nested entry  was created in its place
+        Event::on(Drafts::class, Drafts::EVENT_BEFORE_APPLY_DRAFT, function(DraftEvent $event) {
+            if ($event->draft->propagateAll && $event->draft->getIsUnpublishedDraft()) {
+                $event->draft->propagateAll = false;
+            }
+        });
     }
 }