xC/xP: send buffer type and server state

Also make PM highlighting behaviour consistent.

xC-proto

@@ -19,8 +19,8 @@ struct CommandMessage {
 	case HELLO:
 		u32 version;
 		// If the version check succeeds, the client will receive
-		// an initial stream of BUFFER_UPDATE, BUFFER_STATS, BUFFER_LINE,
-		// and finally a BUFFER_ACTIVATE message.
+		// an initial stream of SERVER_UPDATE, BUFFER_UPDATE, BUFFER_STATS,
+		// BUFFER_LINE, and finally a BUFFER_ACTIVATE message.
 	case ACTIVE:
 		void;
 	case BUFFER_INPUT:
@@ -56,14 +56,33 @@ struct EventMessage {
 		BUFFER_ACTIVATE,
 		BUFFER_LINE,
 		BUFFER_CLEAR,
+		SERVER_UPDATE,
+		SERVER_RENAME,
+		SERVER_REMOVE,
 		ERROR,
 		RESPONSE,
 	} event) {
 	case PING:
 		void;
+
 	case BUFFER_UPDATE:
 		string buffer_name;
 		bool hide_unimportant;
+		union BufferContext switch (enum BufferKind {
+			GLOBAL,
+			SERVER,
+			CHANNEL,
+			PRIVATE_MESSAGE,
+		} kind) {
+		case GLOBAL:
+			void;
+		case SERVER:
+			string server_name;
+		case CHANNEL:
+			string server_name;
+		case PRIVATE_MESSAGE:
+			string server_name;
+		} context;
 	case BUFFER_STATS:
 		string buffer_name;
 		// These are cumulative, even for lines flushed out from buffers.
@@ -130,6 +149,23 @@ struct EventMessage {
 	case BUFFER_CLEAR:
 		string buffer_name;
 
+	case SERVER_UPDATE:
+		string server_name;
+		enum ServerState {
+			DISCONNECTED,
+			CONNECTING,
+			CONNECTED,
+			REGISTERED,
+			DISCONNECTING,
+		} state;
+	case SERVER_RENAME:
+		// Buffers aren't sent updates for in this circumstance,
+		// as that wouldn't be sufficiently atomic anyway.
+		string server_name;
+		string new;
+	case SERVER_REMOVE:
+		string server_name;
+
 	// Restriction: command_seq strictly follows the sequence received
 	// by the relay, across both of these replies.
 	case ERROR: