* variable.c (rb_obj_remove_instance_variable): raise NameError if

specified instance variable is not defined.

* variable.c (generic_ivar_remove): modified to check ivar
  existence.

* file.c (rb_file_s_extname): new method based on the proposal
  (and patch) from Mike Hall. [new]

* eval.c (error_handle): default to 1 unless status is set.

* eval.c (ruby_options): guard error_handle() with PROT_NONE.

* eval.c (ruby_stop): ditto.

* math.c (math_acosh): added. [new]

* math.c (math_asinh): ditto.

* math.c (math_atanh): ditto.

* struct.c (rb_struct_each_pair): method added. [new]

* class.c (rb_singleton_class): wrong condition; was creating
  unnecessary singleton class.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2348 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/cgi/session.rb

@@ -137,6 +137,7 @@ class CGI
       end
 
       def update
+	return unless @hash
 	@f.rewind
 	for k,v in @hash
 	  @f.printf "%s=%s\n", CGI::escape(k), CGI::escape(String(v))