Stop updating name properties if all are already set

CHANGELOG-WIP.md

@@ -14,6 +14,7 @@
 - Added `craft\services\Sites::getSitesByLanguage()`.
 - Added `craft\web\ErrorHandler::exceptionAsArray()`.
 - Added `craft\web\ErrorHandler::showExceptionDetails()`.
+- `craft\base\NameTrait::prepareNamesForSave()` no longer updates the name properties if `fullName`, `firstName`, and `lastName` are already set. ([#14665](https://github.com/craftcms/cms/issues/14665))
 
 ### System
 - Craft now calls `setlocale()` based on the target language, so that `SORT_LOCALE_STRING` behaves as expected. ([#14509](https://github.com/craftcms/cms/issues/14509), [#14513](https://github.com/craftcms/cms/pull/14513))

src/base/NameTrait.php

@@ -57,6 +57,12 @@ protected function normalizeNames(): void
     protected function prepareNamesForSave(): void
     {
         if ($this->fullName !== null) {
+            // if firstName/lastName are also set, just leave them alone
+            // (https://github.com/craftcms/cms/issues/14665)
+            if ($this->firstName !== null || $this->lastName !== null) {
+                return;
+            }
+
             $generalConfig = Craft::$app->getConfig()->getGeneral();
             $languages = [
                 // Load our custom language file first so config settings can override the defaults

src/controllers/UsersController.php

@@ -2695,15 +2695,20 @@ private function populateNameAttributes(object $model): void
 
         if ($fullName !== null) {
             $model->fullName = $fullName;
+
+            // Unset firstName and lastName so NameTrait::prepareNamesForSave() can set them
+            $model->firstName = $model->lastName = null;
         } else {
             // Still check for firstName/lastName in case a front-end form is still posting them
             $firstName = $this->request->getBodyParam('firstName');
             $lastName = $this->request->getBodyParam('lastName');
 
             if ($firstName !== null || $lastName !== null) {
-                $model->fullName = null;
                 $model->firstName = $firstName ?? $model->firstName;
                 $model->lastName = $lastName ?? $model->lastName;
+
+                // Unset fullName so NameTrait::prepareNamesForSave() can set it
+                $model->fullName = null;
             }
         }
     }

src/elements/Address.php

@@ -264,7 +264,11 @@ public function setAttributes($values, $safeOnly = true): void
         }
 
         if (array_key_exists('firstName', $values) || array_key_exists('lastName', $values)) {
+            // Unset fullName so NameTrait::prepareNamesForSave() can set it
             $this->fullName = null;
+        } elseif (array_key_exists('fullName', $values)) {
+            // Unset firstName and lastName so NameTrait::prepareNamesForSave() can set them
+            $this->firstName = $this->lastName = null;
         }
 
         parent::setAttributes($values, $safeOnly);

src/elements/User.php

@@ -906,7 +906,11 @@ public function setAttributes($values, $safeOnly = true): void
         }
 
         if (array_key_exists('firstName', $values) || array_key_exists('lastName', $values)) {
+            // Unset fullName so NameTrait::prepareNamesForSave() can set it
             $this->fullName = null;
+        } elseif (array_key_exists('fullName', $values)) {
+            // Unset firstName and lastName so NameTrait::prepareNamesForSave() can set them
+            $this->firstName = $this->lastName = null;
         }
 
         parent::setAttributes($values, $safeOnly);