Replaced new-line-in-string check with control-char check; tests

json.lua

@@ -198,11 +198,10 @@ local function parse_string(str, i, chr)
   for j = i + 1, #str do
     local x = str:sub(j, j)
 
-    if x == "\n" then
-      decode_error(str, j, "unexpected new line in string")
-    end
+    if x:byte() < 32 then
+      decode_error(str, j, "control character in string")
 
-    if last == "\\" then
+    elseif last == "\\" then
       if x == "u" then 
         local hex = str:sub(j + 1, j + 5)
         if not hex:find("%x%x%x%x") then

test/test.lua

@@ -133,12 +133,14 @@ test("decode invalid", function()
 end)
 
 
-test("decode invalid escape", function()
+test("decode invalid string", function()
   local t = {
     [["\z"]],
     [["\1"]],
     [["\u000z"]],
-    [["\ud83d\ude0q"]]
+    [["\ud83d\ude0q"]],
+    '"x\ny"',
+    '"x\0y"',
   }
   for i, v in ipairs(t) do
     local status, err = pcall(json.decode, v)