lib/omniauth/form.rb in omniauth-1.9.2 vs lib/omniauth/form.rb in omniauth-2.0.0.pre.rc1

@@ -7,10 +7,10 @@
     def initialize(options = {})
       options[:title] ||= 'Authentication Info Required'
       options[:header_info] ||= ''
       self.options = options
 
-      @html = ''
+      @html = +'' # unary + string allows it to be mutable if strings are frozen
       @with_custom_button = false
       @footer = nil
       header(options[:title], options[:header_info])
     end