chaoslawful/lua-nginx-module — pull request #295 by jinglong (2013-10-12 04:19:57+00:00)
Title: bugfix: the client will get a empty Cache_Control header when set Cache_...

For example:
header_filter_by_lua 'ngx.header.Cache_Control = nil';

When there is no Cache_Control header in the original output headers, the client will get a Cache_Control header with a empty value.