+<?php namespace BookStack\Translation;
+
+
+class Translator extends \Illuminate\Translation\Translator
+{
+
+ /**
+ * Mapping of locales to their base locales
+ * @var array
+ */
+ protected $baseLocaleMap = [
+ 'de_informal' => 'de',
+ ];
+
+ /**
+ * Get the translation for a given key.
+ *
+ * @param string $key
+ * @param array $replace
+ * @param string $locale
+ * @return string|array|null
+ */
+ public function trans($key, array $replace = [], $locale = null)
+ {
+ $translation = $this->get($key, $replace, $locale);
+
+ if (is_array($translation)) {
+ $translation = $this->mergeBackupTranslations($translation, $key, $locale);
+ }
+
+ return $translation;
+ }
+
+ /**
+ * Merge the fallback translations, and base translations if existing,
+ * into the provided core key => value array of translations content.
+ * @param array $translationArray
+ * @param string $key
+ * @param null $locale
+ * @return array
+ */
+ protected function mergeBackupTranslations(array $translationArray, string $key, $locale = null)
+ {
+ $fallback = $this->get($key, [], $this->fallback);
+ $baseLocale = $this->getBaseLocale($locale ?? $this->locale);
+ $baseTranslations = $baseLocale ? $this->get($key, [], $baseLocale) : [];
+
+ return array_replace_recursive($fallback, $baseTranslations, $translationArray);
+ }
+
+ /**
+ * Get the array of locales to be checked.
+ *
+ * @param string|null $locale
+ * @return array
+ */
+ protected function localeArray($locale)
+ {
+ $primaryLocale = $locale ?: $this->locale;
+ return array_filter([$primaryLocale, $this->getBaseLocale($primaryLocale), $this->fallback]);
+ }
+
+ /**
+ * Get the locale to extend for the given locale.
+ *
+ * @param string $locale
+ * @return string|null
+ */
+ protected function getBaseLocale($locale)
+ {
+ return $this->baseLocaleMap[$locale] ?? null;
+ }
+
+}
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