Build broken after LuaJIT commit dc320ca

[nzt4567]

LuaJIT commit dc320ca removes some old Lua 5.0 compatibility defines, including luaL_getn which is required for lua-nginx-module. Hotfixed by returning the define but that's not probably the right way to do it ;)

[agentzh]

@nzt4567 Yeah, this ngx_lua module should use lua_objlen instead. Mind to propose a pull request for this change? Thanks for the report!

[centminmod]

yup seems ran into this as well

       -o objs/addon/src/ngx_http_lua_headers.o \
       ../lua-nginx-module-0.10.7/src/ngx_http_lua_headers.c
../lua-nginx-module-0.10.7/src/ngx_http_lua_headers.c: In function ‘ngx_http_lua_ngx_header_set’:
../lua-nginx-module-0.10.7/src/ngx_http_lua_headers.c:721:13: error: implicit declaration of function ‘luaL_getn’ [-Werror=implicit-function-declaration]
        n = luaL_getn(L, 3);
            ^
cc1: all warnings being treated as errors
make[1]: *** [objs/addon/src/ngx_http_lua_headers.o] Error 1
make[1]: Leaving directory `/svr-setup/nginx-1.11.10'
make: *** [build] Error 2

[agentzh]

@dndx Will you take care of this? Thanks!

[dndx]

@agentzh On it

[dndx]

Thanks for reporting @nzt4567 @centminmod

Also fixed the build failure of lua-cjson due to similar change.

openresty/lua-cjson#21
openresty/lua-cjson#22

[nzt4567]

Sorry guys, ongoing vacation is keeping me away from the keyboard most of the time ;) Thanks @dndx @agentzh