Fixes to getMacAddress() and to adding gcode.

src/network/wlanconfig.lua

@@ -102,6 +102,9 @@ function M.getMacAddress()
 	local macText = utils.readFile('/sys/class/net/' .. deviceName .. '/address')
 	local out = ''
 	
+	-- Hack to prevent failure in case the MAC address could not be obtained.
+	if not macText or macText == '' then return "000000000000" end
+	
 	for i = 0, 5 do
 		local bt = string.sub(macText, i*3+1, i*3+2)
 		out = out .. bt

src/rest/api/api_printer.lua

@@ -72,7 +72,10 @@ local function addToGcodeFile(gcode)
 	
 	log:debug("appending " .. gcode:len() .. " bytes of gcode to " .. GCODE_TMP_FILE)
 	gcf:write(gcode)
+	gcf:write("\n")
 	gcf:close()
+	
+	return true
 end
 
 -- assumes printerPath exists, returns true if successful, false if command file already exists and is non-empty (i.e. printer busy),
@@ -210,7 +213,7 @@ function M.print_POST(request, response)
 		response:addData('msg', msg)
 		return
 	else
-		response:addData('gcode_append',gcode:len())
+		response:addData('gcode_append',argGcode:len())
 	end
 	
 	if argIsLast == true then