Add tests for handling errors and unexpected msgs

These new tests verify correct behavior even in the case that an
unexpected message arrives in the middle of handling a request. We also
verify that the socket is closed cleanly in the event of a protocol
error.

test/mochiweb_http_tests.erl

@@ -13,9 +13,16 @@ has_acceptor_bug_test_() ->
      fun mochiweb_http:stop/1,
      fun has_acceptor_bug_tests/1}.
 
+unexpected_msg_test_() ->
+    {setup,
+     fun start_server/0,
+     fun mochiweb_http:stop/1,
+     fun unexpected_msg_in_hdr_tests/1}.
+
 start_server() ->
     application:start(inets),
     {ok, Pid} = mochiweb_http:start_link([{port, 0},
+                                          {acceptor_pool_size,1},
                                           {loop, fun responder/1}]),
     Pid.
 
@@ -43,3 +50,37 @@ has_bug(Port, Len) ->
       {ok, {{"HTTP/1.1", 400, "Bad Request"}, _, []}} ->
           false
   end.
+
+-define(IN_METHOD, 3). % The space after the get.
+-define(IN_HEADER, 20). % The dash after user
+get_req() ->
+    <<"GET / HTTP/1.1\r\n"
+      "User-Agent: mochiweb_http_tests/0.0\r\n"
+      "Accept: */*\r\n\r\n">>.
+
+unexpected_msg(Server, MsgAt, Msg) ->
+    %% Set up with a single acceptor, dig out the pid - sensitive to change in mochiweb_socket_server
+    %% state record.
+    [Acceptor] = sets:to_list(element(14, sys:get_state(Server))),
+    Port = mochiweb_socket_server:get(Server, port),
+    <<Before:MsgAt/binary, After/binary>> = get_req(),
+    {ok, S} = gen_tcp:connect({127,0,0,1},Port,[binary,{active,false}]),
+    ok = gen_tcp:send(S, Before),
+    Acceptor ! Msg,
+    gen_tcp:send(S, After),
+    gen_tcp:recv(S, 0, 5000).
+
+
+unexpected_msg_in_hdr_tests(Server) ->
+    [{"should ignore a message in the middle of the request line",
+      ?_assertMatch({ok, <<"HTTP/1.1 200 OK", _Rest/binary>>},
+		    unexpected_msg(Server, ?IN_METHOD, unexpected_msg_in_your_method))},
+     {"should ignore a message in the middle of a header",
+      ?_assertMatch({ok, <<"HTTP/1.1 200 OK", _Rest/binary>>},
+		    unexpected_msg(Server, ?IN_HEADER, unexpected_msg_in_your_header))},
+     {"should close on a TCP error on the request line",
+      ?_assertMatch({error, closed},
+		    unexpected_msg(Server, ?IN_METHOD, {tcp_error, your_port_you_dont_match_on, something_terrible}))},
+     {"should close on a TCP error in a header",
+      ?_assertMatch({error, closed},
+		    unexpected_msg(Server, ?IN_HEADER, {tcp_error, your_port_you_dont_match_on, something_terrible}))}].