Tidy up new-session and attach-session and change them to work from inside

tmux, switching the current client to the new or requested session.

Written with Josh Elsasser.

cmd-attach-session.c

@@ -44,10 +44,9 @@ cmd_attach_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct cmd_target_data	*data = self->data;
 	struct session		*s;
+	struct client		*c;
 	char			*cause;
-
-	if (ctx->curclient != NULL)
-		return (0);
+	u_int			 i;
 
 	if (ARRAY_LENGTH(&sessions) == 0) {
 		ctx->error(ctx, "no sessions");
@@ -56,24 +55,44 @@ cmd_attach_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 	if ((s = cmd_find_session(ctx, data->target)) == NULL)
 		return (-1);
 
-	if (!(ctx->cmdclient->flags & CLIENT_TERMINAL)) {
-		ctx->error(ctx, "not a terminal");
-		return (-1);
+	if (ctx->cmdclient == NULL) {
+		if (data->chflags & CMD_CHFLAG('d')) {
+			/* 
+			 * Can't use server_write_session in case attaching to
+			 * the same session as currently attached to.
+			 */
+			for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
+				c = ARRAY_ITEM(&clients, i);
+				if (c == NULL || c->session != s)
+					continue;
+				if (c == ctx->curclient)
+					continue;
+				server_write_client(c, MSG_DETACH, NULL, 0);
+			}
+		}
+		
+		ctx->curclient->session = s;
+		server_redraw_client(ctx->curclient);
+	} else {
+		if (!(ctx->cmdclient->flags & CLIENT_TERMINAL)) {
+			ctx->error(ctx, "not a terminal");
+			return (-1);
+		}
+
+		if (tty_open(&ctx->cmdclient->tty, &cause) != 0) {
+			ctx->error(ctx, "terminal open failed: %s", cause);
+			xfree(cause);
+			return (-1);
+		}
+
+		if (data->chflags & CMD_CHFLAG('d'))
+			server_write_session(s, MSG_DETACH, NULL, 0);
+
+		ctx->cmdclient->session = s;
+		server_write_client(ctx->cmdclient, MSG_READY, NULL, 0);
+		server_redraw_client(ctx->cmdclient);
 	}
-
-	if (tty_open(&ctx->cmdclient->tty, &cause) != 0) {
-		ctx->error(ctx, "terminal open failed: %s", cause);
-		xfree(cause);
-		return (-1);
-	}
-
-	if (data->chflags & CMD_CHFLAG('d'))
-		server_write_session(s, MSG_DETACH, NULL, 0);
-	ctx->cmdclient->session = s;
-
-	server_write_client(ctx->cmdclient, MSG_READY, NULL, 0);
 	recalculate_sizes();
-	server_redraw_client(ctx->cmdclient);
 
-	return (1);
+	return (1);	/* 1 means don't tell command client to exit */
 }

cmd-new-session.c

@@ -111,65 +111,80 @@ int
 cmd_new_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct cmd_new_session_data	*data = self->data;
-	struct client			*c = ctx->cmdclient;
 	struct session			*s;
 	char				*cmd, *cwd, *cause;
 	u_int				 sx, sy;
 
-	if (ctx->curclient != NULL)
-		return (0);
-
-	if (!data->flag_detached) {
-		if (c == NULL) {
-			ctx->error(ctx, "no client to attach to");
-			return (-1);
-		}
-		if (!(c->flags & CLIENT_TERMINAL)) {
-			ctx->error(ctx, "not a terminal");
-			return (-1);
-		}
-	}
-
 	if (data->newname != NULL && session_find(data->newname) != NULL) {
 		ctx->error(ctx, "duplicate session: %s", data->newname);
 		return (-1);
 	}
 
-	cmd = data->cmd;
-	if (cmd == NULL)
-		cmd = options_get_string(&global_s_options, "default-command");
-	if (c == NULL || c->cwd == NULL)
-		cwd = options_get_string(&global_s_options, "default-path");
+	/*
+	 * There are two cases:
+	 *
+	 * 1. If cmdclient is non-NULL, new-session has been called from the
+	 *    command-line - cmdclient is to become a new attached, interactive
+	 *    client. Unless -d is given, the terminal must be opened and then
+	 *    the client sent MSG_READY.
+	 *
+	 * 2. If cmdclient is NULL, new-session has been called from an
+	 *    existing client (such as a key binding).
+	 *
+	 * In both cases, a new additional session needs to be created and
+	 * (unless -d) set as the current session for the client.
+	 */
+
+	/* Open the terminal if necessary. */
+	if (!data->flag_detached && ctx->cmdclient != NULL) {
+		if (!(ctx->cmdclient->flags & CLIENT_TERMINAL)) {
+			ctx->error(ctx, "not a terminal");
+			return (-1);
+		}
+		
+		if (tty_open(&ctx->cmdclient->tty, &cause) != 0) {
+			ctx->error(ctx, "open terminal failed: %s", cause);
+			xfree(cause);
+			return (-1);
+		}
+	}
+
+	/* Find new session size and options. */
+	if (data->flag_detached) {
+		sx = 80;
+		sy = 25;
+	} else {
+		if (ctx->cmdclient != NULL) {
+			sx = ctx->cmdclient->tty.sx;
+			sy = ctx->cmdclient->tty.sy;
+		} else {
+			sx = ctx->curclient->tty.sx;
+			sy = ctx->curclient->tty.sy;
+		}
+	}
+	if (sy > 0 && options_get_number(&global_s_options, "status"))
+		sy--;
+	if (sx == 0)
+		sx = 1;
+	if (sy == 0)
+		sy = 1;
+	if (ctx->cmdclient != NULL && ctx->cmdclient->cwd != NULL)
+		cwd = ctx->cmdclient->cwd;
 	else
-		cwd = c->cwd;
-
-	sx = 80;
-	sy = 25;
-	if (!data->flag_detached) {
-		sx = c->tty.sx;
-		sy = c->tty.sy;
-	}
-
-	if (options_get_number(&global_s_options, "status")) {
-		if (sy == 0)
-			sy = 1;
-		else
-			sy--;
-	}
-
-	if (!data->flag_detached && tty_open(&c->tty, &cause) != 0) {
-		ctx->error(ctx, "open terminal failed: %s", cause);
-		xfree(cause);
-		return (-1);
-	}
-
+		cwd = options_get_string(&global_s_options, "default-path");
+	if (data->cmd != NULL)
+		cmd = data->cmd;
+	else
+		cmd = options_get_string(&global_s_options, "default-command");
 
+	/* Create the new session. */
 	s = session_create(data->newname, cmd, cwd, sx, sy, &cause);
 	if (s == NULL) {
 		ctx->error(ctx, "create session failed: %s", cause);
 		xfree(cause);
 		return (-1);
 	}
+
 	if (data->winname != NULL) {
 		xfree(s->curw->window->name);
 		s->curw->window->name = xstrdup(data->winname);
@@ -177,17 +192,31 @@ cmd_new_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 		    &s->curw->window->options, "automatic-rename", 0);
 	}
 
-	if (data->flag_detached) {
-		if (c != NULL)
-			server_write_client(c, MSG_EXIT, NULL, 0);
-	} else {
-		c->session = s;
-		server_write_client(c, MSG_READY, NULL, 0);
-		server_redraw_client(c);
+	/* 
+	 * If a command client exists, it is either taking this session (and
+	 * needs to get MSG_READY and stay around), or -d is given and it needs
+	 * to exit.
+	 */
+	if (ctx->cmdclient != NULL) {
+		if (!data->flag_detached)
+			server_write_client(ctx->cmdclient, MSG_READY, NULL, 0);
+		else 
+			server_write_client(ctx->cmdclient, MSG_EXIT, NULL, 0);
+	}
+	
+	/* Set the client to the new session. */
+ 	if (!data->flag_detached) {
+		if (ctx->cmdclient != NULL) {
+ 			ctx->cmdclient->session = s;
+			server_redraw_client(ctx->cmdclient);
+		} else {
+ 			ctx->curclient->session = s;
+			server_redraw_client(ctx->curclient);
+		}
 	}
 	recalculate_sizes();
 
-	return (1);
+	return (1);	/* 1 means don't tell command client to exit */
 }
 
 void

tmux.1

@@ -596,7 +596,11 @@ The following commands are available:
 .Op Fl t Ar target-session
 .Xc
 .D1 (alias: Ic attach )
-Create a new client in the current terminal and attach it to a session.
+If run from outside
+.Nm ,
+create a new client in the current terminal and attach it to
+.Ar target-session .
+If used from inside, switch the current client.
 If
 .Fl d
 is specified, any other clients attached to the session are detached.

tmux.h

@@ -835,8 +835,18 @@ struct client_ctx {
 struct cmd_ctx {
 	struct client  *cmdclient;
 
+	/*
+	 * curclient is the client where this command was executed if inside
+	 * tmux. This is NULL if the command came from the command-line.
+	 *
+	 * cmdclient is the client which sent the MSG_COMMAND to the server, if
+	 * any. This is NULL unless the command came from the command-line.
+	 *
+	 * One of curclient or cmdclient is always NULL and the other not.
+	 */
 	struct client  *curclient;
 	struct session *cursession;
+
 	struct msg_command_data	*msgdata;
 
 	void		(*print)(struct cmd_ctx *, const char *, ...);