2 files changed, 7 insertions, 2 deletions

diff --git a/install.bat b/install.bat
index 42b01c43..f64d6783 100644
--- a/install.bat
+++ b/install.bat
@@ -8,6 +8,7 @@ local vars = {}
 vars.PREFIX = nil

 vars.VERSION = "2.2"

 vars.SYSCONFDIR = nil

+vars.SYSCONFFORCE = nil

 vars.CONFBACKUPDIR = nil

 vars.SYSCONFFILENAME = nil

 vars.CONFIG_FILE = nil

@@ -199,6 +200,7 @@ local function parse_options(args)
                         vars.PREFIX = option.value

                 elseif name == "/CONFIG" then

                         vars.SYSCONFDIR = option.value

+                        vars.SYSCONFFORCE = true

                 elseif name == "/TREE" then

                         vars.TREE_ROOT = option.value

                 elseif name == "/SCRIPTS" then

@@ -650,6 +652,7 @@ vars.SYSCONFFILENAME = S"config-$LUA_VERSION.lua"
 vars.CONFIG_FILE = vars.SYSCONFDIR.."\\"..vars.SYSCONFFILENAME

 if SELFCONTAINED then

         vars.SYSCONFDIR = vars.PREFIX

+        vars.SYSCONFFORCE = true

         vars.TREE_ROOT = vars.PREFIX..[[\systree]]

         REGISTRY = false

 end

@@ -835,7 +838,6 @@ else
 end

 f:write(S[=[

 site_config.LUAROCKS_UNAME_M=[[$UNAME_M]]

-site_config.LUAROCKS_SYSCONFIG=[[$CONFIG_FILE]]

 site_config.LUAROCKS_ROCKS_TREE=[[$TREE_ROOT]]

 site_config.LUAROCKS_PREFIX=[[$PREFIX]]

 site_config.LUAROCKS_DOWNLOADER=[[wget]]

@@ -844,6 +846,9 @@ site_config.LUAROCKS_MD5CHECKER=[[md5sum]]
 if FORCE_CONFIG then

         f:write("site_config.LUAROCKS_FORCE_CONFIG=true\n")

 end

+if vars.SYSCONFFORCE then  -- only write this value when explcitly given, otherwise rely on defaults

+        f:write("site_config.LUAROCKS_SYSCONFIG=[[$CONFIG_FILE]]\n")

+end

 f:write("return site_config\n")

 f:close()

 print(S([[Created LuaRocks site-config file: $LUADIR\luarocks\]]..site_config..[[.lua]]))

diff --git a/src/luarocks/cfg.lua b/src/luarocks/cfg.lua
index e3d6e74b..79b399f0 100644
--- a/src/luarocks/cfg.lua
+++ b/src/luarocks/cfg.lua
@@ -149,7 +149,7 @@ local sys_config_file_default, home_config_file_default
 local sys_config_dir, home_config_dir
 local sys_config_ok, home_config_ok = false, false
 local extra_luarocks_module_dir
-sys_config_dir = site_config.LUAROCKS_SYSCONFDIR
+sys_config_dir = site_config.LUAROCKS_SYSCONFDIR or site_config.LUAROCKS_PREFIX
 if cfg.platforms.windows then
    cfg.home = os.getenv("APPDATA") or "c:"
    sys_config_dir = sys_config_dir or "c:/luarocks"