BUG/MEDIUM: hlua: Don't loop if a lua socket does not consume receive…

…d data

If some data are received for a lua socket while the lua script responsible
to consume these data is not ready to do so, for instance because it is
sleeping, the applet is woken up in loop because it never states it will not
consume these data yet.

To fix the issue, in the applet I/O handle, when there are outgoing data, we
always pretend the applet will not consume it. It is the responsibility to
the lua script to reactivate receives by calling Socket.receive() function.

This patch must be backported to every stable version. For 2.4 and older,
si_want_get()/si_cant_get() must be used instead of
applet_will_consume()/applet_wont_consume().

src/hlua.c

@@ -2352,8 +2352,10 @@ static void hlua_socket_handler(struct appctx *appctx)
 		notification_wake(&ctx->wake_on_write);
 
 	/* Wake the tasks which wants to read if the buffer contains data. */
-	if (co_data(sc_oc(sc)))
+	if (co_data(sc_oc(sc))) {
 		notification_wake(&ctx->wake_on_read);
+		applet_wont_consume(appctx);
+	}
 
 	/* If write notifications are registered, we considers we want
 	 * to write, so we clear the blocking flag.
@@ -2622,6 +2624,7 @@ __LJMP static int hlua_socket_receive_yield(struct lua_State *L, int status, lua
 	co_skip(oc, len + skip_at_end);
 
 	/* Don't wait anything. */
+	applet_will_consume(appctx);
 	appctx_wakeup(appctx);
 
 	/* If the pattern reclaim to read all the data