[Translations] Xliff - Fix exporting source document data (pimcore#16269)

* [Translations] Xliff - Fix exporting source document data - resolves pimcore#16037

* review changes

Author: dvesh3

bundles/XliffBundle/src/ExportDataExtractorService/DataExtractor/DocumentDataExtractor.php

@@ -79,6 +79,8 @@ protected function addDocumentEditables(Document $document, AttributeSet $result
 
         $translations = $service->getTranslations($document);
 
+        $this->resetSourceDocument($document, $result, $translations);
+
         if ($document instanceof Document\PageSnippet) {
             $editableNames = $this->EditableUsageResolver->getUsedEditableNames($document);
             foreach ($editableNames as $editableName) {
@@ -129,6 +131,8 @@ protected function addSettings(Document $document, AttributeSet $result): Docume
         $service = new Document\Service;
         $translations = $service->getTranslations($document);
 
+        $this->resetSourceDocument($document, $result, $translations);
+
         if ($document instanceof Document\Page) {
             $data = [
                 'title' => $document->getTitle(),
@@ -171,4 +175,18 @@ protected function doExportProperty(Property $property): bool
                     'navigation_tabindex',
                 ]);
     }
+
+    private function resetSourceDocument(Document &$document, AttributeSet $result, array $translations): void
+    {
+        if ($result->getSourceLanguage() != $result->getTargetLanguages()) {
+            $sourceDocumentId = $translations[$result->getSourceLanguage()] ?? false;
+            if ($sourceDocumentId) {
+                $sourceDocument = Document::getById($sourceDocumentId);
+
+                if ($sourceDocument instanceof Document\PageSnippet) {
+                    $document = $sourceDocument;
+                }
+            }
+        }
+    }
 }