REGTEST: lua: check socket functionality from a lua-task

Adding a new test /reg-tests/lua/b00004.vtc which checks if the core.tcp()
socket basic functions properly when used from a lua-task
diff --git a/reg-tests/lua/b00004.lua b/reg-tests/lua/b00004.lua
new file mode 100644
index 0000000..3ad14fe
--- /dev/null
+++ b/reg-tests/lua/b00004.lua
@@ -0,0 +1,44 @@
+
+local vtc_port = 0
+
+core.register_service("fakeserv", "http", function(applet)
+	vtc_port = applet.headers["vtcport"][0]
+	core.Info("APPLET START")
+	local response = "OK"
+	applet:add_header("Server", "haproxy/webstats")
+	applet:add_header("Content-Length", string.len(response))
+	applet:add_header("Content-Type", "text/html")
+	applet:start_response()
+	applet:send(response)
+	core.Info("APPLET DONE")
+end)
+
+local function cron()
+	-- wait for until the correct port is set through the c0 request..
+	while vtc_port == 0 do
+		core.msleep(1)
+	end
+	core.Debug('CRON port:' .. vtc_port)
+
+	local socket = core.tcp()
+	local success = socket:connect("127.0.0.1", vtc_port)
+	core.Info("SOCKET MADE ".. (success or "??"))
+	if success ~= 1 then
+		core.Info("CONNECT SOCKET FAILED?")
+		return
+	end
+	local request = "GET / HTTP/1.1\r\n\r\n"
+	core.Info("SENDING REQUEST")
+	socket:send(request)
+	local result = ""
+	repeat
+		core.Info("4")
+		local d = socket:receive("*a")
+		if d ~= nil then
+			result = result .. d
+		end
+	until d == nil or d == 0
+	core.Info("Received: "..result)
+end
+
+core.register_task(cron)
\ No newline at end of file
diff --git a/reg-tests/lua/b00004.vtc b/reg-tests/lua/b00004.vtc
new file mode 100644
index 0000000..91b5dde
--- /dev/null
+++ b/reg-tests/lua/b00004.vtc
@@ -0,0 +1,34 @@
+varnishtest "Lua: check socket functionality from a lua-task"
+feature ignore_unknown_macro
+
+#REQUIRE_OPTIONS=LUA
+#REQUIRE_VERSION=1.6
+
+server s1 {
+    rxreq
+    txresp -bodylen 20
+} -start
+
+haproxy h1 -conf {
+    global
+        lua-load ${testdir}/b00004.lua
+
+    frontend fe1
+        mode http
+        bind "fd@${fe1}"
+        default_backend b1
+
+    backend b1
+        mode http
+        http-request use-service lua.fakeserv
+
+} -start
+
+client c0 -connect ${h1_fe1_sock} {
+    txreq -url "/" -hdr "vtcport: ${s1_port}"
+    rxresp
+    expect resp.status == 200
+} -run
+
+
+server s1 -wait
\ No newline at end of file