fix error when field definition has changed

CHANGELOG.md

@@ -0,0 +1,5 @@
+Master branch
+=============
+
+- fix error on export: error when field definition has changed
+

CustomFields/CustomFieldChoice.php

@@ -361,6 +361,16 @@ class CustomFieldChoice extends AbstractCustomField
         }
     }
     
+    /**
+     * Return true if the choice given in $choiceSlug is checked inside $data.
+     * 
+     * Used in list exports.
+     * 
+     * @param CustomField $cf
+     * @param string $choiceSlug the slug of the choice we want to know if it was checked
+     * @param array|string $data the data of the field
+     * @return boolean
+     */
     public function isChecked(CustomField $cf, $choiceSlug, $data) 
     {
         if ($data === null) {
@@ -369,15 +379,15 @@ class CustomFieldChoice extends AbstractCustomField
         
         if ($cf->getOptions()[self::MULTIPLE]) {
             if ($cf->getOptions()[self::ALLOW_OTHER]) {
-                return \in_array($choiceSlug, $data['_choices']);
+                return \in_array($choiceSlug, $this->deserialize($data, $cf)['_choices']);
             } else {
-                return \in_array($choiceSlug, $data);
+                return \in_array($choiceSlug, $this->deserialize($data, $cf));
             }
         } else {
             if ($cf->getOptions()[self::ALLOW_OTHER]) {
-                return $data['_choices'] === $choiceSlug;
+                return $this->deserialize($data, $cf)['_choices'] === $choiceSlug;
             } else {
-                return $data === $choiceSlug;
+                return $this->deserialize($data, $cf) === $choiceSlug;
             }
         }
     }