// Fix group reduction per category

classes/GroupReduction.php

@@ -137,6 +137,7 @@ class GroupReductionCore extends ObjectModel
 			SELECT `reduction`
 			FROM `'._DB_PREFIX_.'product_group_reduction_cache`
 			WHERE `id_product` = '.(int)$id_product.' AND `id_group` = '.(int)$id_group);
+		// Should return string (decimal in database) and not a float
 		return self::$reduction_cache[$id_product.'-'.$id_group];
 	}