Show session name in detached message. Requested by somebody a few

months ago who didn't bother testing it. But it works for me anyway.

client.c

@@ -48,6 +48,7 @@ enum {
 } client_exitreason = CLIENT_EXIT_NONE;
 int		client_exitval;
 enum msgtype	client_exittype;
+const char     *client_exitsession;
 int		client_attached;
 
 int		client_get_lock(char *);
@@ -138,12 +139,24 @@ failed:
 const char *
 client_exit_message(void)
 {
+	static char msg[256];
+
 	switch (client_exitreason) {
 	case CLIENT_EXIT_NONE:
 		break;
 	case CLIENT_EXIT_DETACHED:
+		if (client_exitsession != NULL) {
+			xsnprintf(msg, sizeof msg, "detached "
+			    "(from session %s)", client_exitsession);
+			return (msg);
+		}
 		return ("detached");
 	case CLIENT_EXIT_DETACHED_HUP:
+		if (client_exitsession != NULL) {
+			xsnprintf(msg, sizeof msg, "detached and SIGHUP "
+			    "(from session %s)", client_exitsession);
+			return (msg);
+		}
 		return ("detached and SIGHUP");
 	case CLIENT_EXIT_LOST_TTY:
 		return ("lost tty");
@@ -582,6 +595,7 @@ client_dispatch_wait(void *data0)
 			shell_exec(data, data0);
 			/* NOTREACHED */
 		case MSG_DETACH:
+		case MSG_DETACHKILL:
 			client_write_server(MSG_EXITING, NULL, 0);
 			break;
 		case MSG_EXITED:
@@ -613,11 +627,12 @@ client_dispatch_attached(void)
 
 		log_debug("got %d from server", imsg.hdr.type);
 		switch (imsg.hdr.type) {
-		case MSG_DETACHKILL:
 		case MSG_DETACH:
-			if (datalen != 0)
+		case MSG_DETACHKILL:
-				fatalx("bad MSG_DETACH size");
+			if (datalen == 0 || data[datalen - 1] != '\0')
+				fatalx("bad MSG_DETACH string");
 
+			client_exitsession = xstrdup(data);
 			client_exittype = imsg.hdr.type;
 			if (imsg.hdr.type == MSG_DETACHKILL)
 				client_exitreason = CLIENT_EXIT_DETACHED_HUP;

cmd-attach-session.c

@@ -77,7 +77,9 @@ cmd_attach_session(struct cmd_q *cmdq, const char *tflag, int dflag, int rflag,
 					continue;
 				if (c == cmdq->client)
 					continue;
-				server_write_client(c, MSG_DETACH, NULL, 0);
+				server_write_client(c, MSG_DETACH,
+				    c->session->name,
+				    strlen(c->session->name) + 1);
 			}
 		}
 
@@ -138,8 +140,10 @@ cmd_attach_session(struct cmd_q *cmdq, const char *tflag, int dflag, int rflag,
 		if (rflag)
 			cmdq->client->flags |= CLIENT_READONLY;
 
-		if (dflag)
+		if (dflag) {
-			server_write_session(s, MSG_DETACH, NULL, 0);
+			server_write_session(s, MSG_DETACH, s->name,
+			    strlen(s->name) + 1);
+		}
 
 		update = options_get_string(&s->options, "update-environment");
 		environ_update(update, &cmdq->client->environ, &s->environ);

cmd-detach-client.c

@@ -18,6 +18,8 @@
 
 #include <sys/types.h>
 
+#include <string.h>
+
 #include "tmux.h"
 
 /*
@@ -40,8 +42,8 @@ cmd_detach_client_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args	*args = self->args;
 	struct client	*c, *c2;
-	struct session 	*s;
+	struct session	*s;
-	enum msgtype     msgtype;
+	enum msgtype	 msgtype;
 	u_int 		 i;
 
 	if (args_has(args, 'P'))
@@ -56,8 +58,10 @@ cmd_detach_client_exec(struct cmd *self, struct cmd_q *cmdq)
 
 		for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
 			c = ARRAY_ITEM(&clients, i);
-			if (c != NULL && c->session == s)
+			if (c == NULL || c->session != s)
-				server_write_client(c, msgtype, NULL, 0);
+				continue;
+			server_write_client(c, msgtype, c->session->name,
+			    strlen(c->session->name) + 1);
 		}
 	} else {
 		c = cmd_find_client(cmdq, args_get(args, 't'), 0);
@@ -69,10 +73,14 @@ cmd_detach_client_exec(struct cmd *self, struct cmd_q *cmdq)
 				c2 = ARRAY_ITEM(&clients, i);
 				if (c2 == NULL || c == c2)
 					continue;
-				server_write_client(c2, msgtype, NULL, 0);
+				server_write_client(c2, msgtype,
+				    c2->session->name,
+				    strlen(c2->session->name) + 1);
 			}
-		} else
+		} else {
-			server_write_client(c, msgtype, NULL, 0);
+			server_write_client(c, msgtype, c->session->name,
+			    strlen(c->session->name) + 1);
+		}
 	}
 
 	return (CMD_RETURN_STOP);