From 1f25b6eb30c1aee66f1e463c411f32fa0691ab46 Mon Sep 17 00:00:00 2001
From: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Date: Tue, 17 Jan 2017 03:59:19 -0500
Subject: [PATCH] net/*: Robustify calls to json parsers

---
 net/nwfmqtt.lua     | 4 ++--
 net/nwfnet-go.lua   | 4 ++--
 net/nwfnet-sntp.lua | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/nwfmqtt.lua b/net/nwfmqtt.lua
index e17e81b..9172589 100644
--- a/net/nwfmqtt.lua
+++ b/net/nwfmqtt.lua
@@ -4,7 +4,7 @@ local self = {}
 function self.mkclient(cf) -- construct a client with config from json file cf
   local c, k, u, p, l
   if file.open(cf) then
-    local conf = cjson.decode(file.read())
+    local conf = cjson.decode(file.read() or "")
     if type(conf) == "table" then
       c = conf["clientid"]; k = conf["keepalive"]; u = conf["user"]; p = conf["pass"]; l = conf["clean"]
     end
@@ -24,7 +24,7 @@ end
 function self.connect(m,cf) -- make a connection with parameters from json file cf
   local broker, port, secure
   if file.open(cf) then
-    local conf = cjson.decode(file.read())
+    local conf = cjson.decode(file.read() or "")
     if type(conf) == "table" then
       broker = conf["broker"]; port = conf["port"]; secure = conf["secure"]
     end
diff --git a/net/nwfnet-go.lua b/net/nwfnet-go.lua
index 962c142..628813f 100644
--- a/net/nwfnet-go.lua
+++ b/net/nwfnet-go.lua
@@ -11,7 +11,7 @@ wifi.eventmon.register(wifi.eventmon.STA_DISCONNECTED, function(t) (require "nwf
 -- One-shot configuration options; useful to change many things at once
 -- at the next boot; all of these options are persisted by the ESP
 if file.open("nwfnet.conf","r") then
-  local conf = cjson.decode(file.read())
+  local conf = cjson.decode(file.read() or "")
   if type(conf) == "table" then
     local essid = conf["sta_essid"]; local pw = conf["sta_pw"]
     if essid ~= nil and pw ~= nil then wifi.sta.config(essid,pw,0) end
@@ -47,7 +47,7 @@ if file.open("nwfnet.cert","r") then
 end
 
 if file.open("nwfnet.conf2","r") then
-  local conf = cjson.decode(file.read())
+  local conf = cjson.decode(file.read() or "")
   if type(conf) == "table" then
     if conf["verify"] == 1 then print("Enabling certificate verification"); pcall(net.cert.verify,true) end
    else print("nwfnet.conf2 malformed")
diff --git a/net/nwfnet-sntp.lua b/net/nwfnet-sntp.lua
index 059f7d1..fc43089 100644
--- a/net/nwfnet-sntp.lua
+++ b/net/nwfnet-sntp.lua
@@ -2,7 +2,7 @@ local function dosntp(server)
   local nn = require "nwfnet"
   if not server then
     if file.open("nwfnet.conf2","r") then
-      local conf = cjson.decode(file.read())
+      local conf = cjson.decode(file.read() or "")
       if type(conf) == "table" then
         if conf["sntp"]   then print("Setting SNTP server"); server = conf["sntp"] end
        else print("nwfnet.conf2 malformed")
-- 
2.50.1