Workaround for a problem in ICU library < 4.9

- Used to cause formatCurrency to fail if locale had comma as a decimal separator.

module/VuFind/src/VuFind/View/Helper/Root/SafeMoneyFormat.php

@@ -88,8 +88,15 @@ class SafeMoneyFormat extends AbstractHelper
             $currency = $this->defaultCurrency;
         }
         $escaper = $this->getView()->plugin('escapeHtml');
-        return $escaper(
+        // Workaround for a problem in ICU library < 4.9 causing formatCurrency to
+        // fail if locale has comma as a decimal separator.
+        // (see https://bugs.php.net/bug.php?id=54538)
+        $locale = setlocale(LC_ALL, 0);
+        setlocale(LC_ALL, ['en_us.UTF-8', 'en_us.UTF8', 'en_us']);
+        $result = $escaper(
             $this->formatter->formatCurrency((float)$number, $currency)
         );
+        setlocale(LC_ALL, $locale);
+        return $result;
     }
 }