[LUA] Set variables according to if file exists

Heya

I'm using Awesome WM with the Vicious widget library.
As i'm using multi boot, Win8, Fedora and Arch, i have my WM-Config shared accross my GNU/Linux installations.

The regarding snippet:

-- Functions
	-- Its just a workaround for an 'unstable' 'hwmon/hwmon[12]' definition of Fedora21 - Rawhide
	-- Function (only) from: http://stackoverflow.com/questions/4990990/lua-check-if-a-file-exists
	function file_exists(name)
		local f=io.open(name,"r")
		if f~=nil then io.close(f) return true else return false end
	end
-- Apps - system specific
	editor = os.getenv("EDITOR") or "notepadqq"
	if file_exists("/etc/favicon.png")
	then	-- Its fedora / I have my rpm repo
		--editor = os.getenv("EDITOR") or "notepadqq"
		editor_cmd = terminal .. " -e " .. editor
		
		os_icon = wibox.widget.imagebox()
		os_icon:set_image("/etc/favicon.png")
	else	-- Probably Arch
		--editor = os.getenv("EDITOR") or "pluma"
		editor_cmd = terminal .. " -e " .. editor
		
		os_icon = wibox.widget.imagebox()
		ARCH_IMG = awful.util.getdir("config") .. "themes/icons/arch-blue-transparent_smaller.png"
		os_icon:set_image(ARCH_IMG)
		--os_icon:set_image(awful.util.getdir("config") .. "themes/icons/arch-blue-transparent_small.png")
	end
-- .....
	mylauncher = awful.widget.launcher({ image = beautiful.os_icon,
		                             menu = mymainmenu })

The full config, without the changes can be seen at: awesome/rc.lua at master · sri-arjuna/awesome · GitHub

Issue is, it loads successfull, as in: no warnings or error messages shown.
BUT, i dont get the the distro icon shown, and therefor no menu is available (other than the hotkey to show it).
(EDIT: in neither of the distros, used to work in fedora, see remote code)

Eventhough i did quite a few changes at that lua code, i dont 'know' lua well enough to figure this...

Any advices please?
Tia