[DOC] Explain flux parent assignment for translations

Refs FluidTYPO3#1176

Classes/Service/ContentService.php

@@ -292,12 +292,18 @@ public function initializeRecord($id, array &$row, DataHandler $tceMain) {
 	 */
 	protected function initializeRecordByNewAndOldAndLanguageUids($row, $newUid, $oldUid, $newLanguageUid, $languageFieldName, DataHandler $tceMain) {
 		if (0 < $newUid && 0 < $oldUid && 0 < $newLanguageUid) {
+			// Get the origin record of the current record to find out if it has any
+			// parameters we need to adapt in the current record.
 			$oldRecord = $this->loadRecordFromDatabase($oldUid);
 			if ($oldRecord[$languageFieldName] !== $newLanguageUid && $oldRecord['pid'] === $row['pid'] && MathUtility::canBeInterpretedAsInteger($oldRecord['tx_flux_parent']) && $oldRecord['tx_flux_parent'] > 0) {
-				// look for the translated version of the parent record indicated
-				// in this new, translated record. Below, we adjust the parent UID
-				// so it has the UID of the translated parent if one exists.
-				$translatedParents = (array) $this->workspacesAwareRecordService->get('tt_content', 'uid,sys_language_uid', "t3_origuid = '" . $oldRecord['tx_flux_parent'] . "'" . BackendUtility::deleteClause('tt_content'));
+				// If the origin record has a flux parent assigned, then look for the
+				// translated, very last version this parent record and, if any valid record was found,
+				// assign its UID as flux parent to the current record.
+				$translatedParents = (array) $this->workspacesAwareRecordService->get(
+					'tt_content',
+					'uid,sys_language_uid',
+					't3_origuid=' . $oldRecord['tx_flux_parent'] . BackendUtility::deleteClause('tt_content')
+				);
 				foreach ($translatedParents as $translatedParent) {
 					if ($translatedParent['sys_language_uid'] == $newLanguageUid) {
 						// set $translatedParent to the right language ($newLanguageUid):