wesnothd: Only reset the commands FIFO stream when reloading if needed

May or may not fix the issue noted in commit
62eb55a regarding the SIGHUP handler,
which is in charge of scheduling load_config() to run. Rather
unfortunately, I'm unable to reproduce the issue on my own machine, so
I'll have to take this to production and test it live.

src/server/server.cpp

@@ -332,6 +332,7 @@ server::server(int port, const std::string& config_file, size_t min_threads,
 	not_logged_in_(),
 	rooms_(players_),
 	input_(),
+	input_path_(),
 	config_file_(config_file),
 	cfg_(read_config()),
 	accepted_versions_(),
@@ -498,8 +499,11 @@ void server::load_config() {
 # endif
 #endif
 	const std::string fifo_path = (cfg_["fifo_path"].empty() ? std::string(FIFODIR) + "/socket" : std::string(cfg_["fifo_path"]));
-	input_.reset();
-	input_.reset(new input_stream(fifo_path));
+	// Reset (replace) the input stream only if the FIFO path changed.
+	if(fifo_path != input_path_) {
+		input_.reset(new input_stream(fifo_path));
+	}
+	input_path_ = fifo_path;
 
 	save_replays_ = cfg_["save_replays"].to_bool();
 	replay_save_path_ = cfg_["replay_save_path"].str();

src/server/server.hpp

@@ -101,6 +101,7 @@ class server
 
 	/** server socket/fifo. */
 	boost::scoped_ptr<input_stream> input_;
+	std::string input_path_;
 
 	const std::string config_file_;
 	config cfg_;