Fix value and validation-related issues in TI18nFormField

See #2509

diff --git a/wcfsetup/install/files/lib/system/form/builder/field/TI18nFormField.class.php b/wcfsetup/install/files/lib/system/form/builder/field/TI18nFormField.class.php
index ed88f6e71553f35f12452c2c5daccdacb52d0bae..b2182a44845489dbe5c70484fd418a15233688c6 100644 (file)
--- a/wcfsetup/install/files/lib/system/form/builder/field/TI18nFormField.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/field/TI18nFormField.class.php
@@ -9,6 +9,7 @@ use wcf\system\form\builder\IFormDocument;
 use wcf\system\form\builder\IFormNode;
 use wcf\system\language\I18nHandler;
 use wcf\system\Regex;
+use wcf\util\ArrayUtil;
 use wcf\util\StringUtil;
 
 /**
@@ -340,7 +341,9 @@ trait TI18nFormField {
                                $this->setStringValue($value);
                        }
                        else if (is_array($value)) {
-                               I18nHandler::getInstance()->setValues($this->getPrefixedId(), $value);
+                               if (!empty($value)) {
+                                       I18nHandler::getInstance()->setValues($this->getPrefixedId(), $value);
+                               }
                        }
                        else {
                                throw new \InvalidArgumentException("Given value is neither a string nor an array, " . gettype($value) . " given.");
@@ -364,12 +367,16 @@ trait TI18nFormField {
         * nodes are valid. A `IFormField` object is valid if its value is valid.
         */
        public function validate() {
-               if (!I18nHandler::getInstance()->validateValue($this->getPrefixedId(), $this->isI18nRequired(), !$this->isRequired())) {
-                       if ($this->hasPlainValue()) {
-                               $this->addValidationError(new FormFieldValidationError('empty'));
-                       }
-                       else {
-                               $this->addValidationError(new FormFieldValidationError('multilingual'));
+               // if i18n is required for a non-required field and the field is
+               // empty, that is no error
+               if ($this->isI18n() && (!empty(ArrayUtil::trim($this->getValue()))) || $this->isRequired()) {
+                       if (!I18nHandler::getInstance()->validateValue($this->getPrefixedId(), $this->isI18nRequired(), !$this->isRequired())) {
+                               if ($this->hasPlainValue()) {
+                                       $this->addValidationError(new FormFieldValidationError('empty'));
+                               }
+                               else {
+                                       $this->addValidationError(new FormFieldValidationError('multilingual'));
+                               }
                        }
                }
        }