From 37f17a7e5b42156a325f2f3207610455cb004ad0 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Fri, 12 Oct 2007 14:46:48 +0000
Subject: [PATCH] Warn and bork on nested sessions ($TMUX exists).

---
 CHANGES              | 3 ++-
 TODO                 | 1 -
 cmd-attach-session.c | 4 ++--
 cmd-new-session.c    | 4 ++--
 server-msg.c         | 8 +++++++-
 tmux.c               | 5 +++--
 tmux.h               | 3 ++-
 7 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/CHANGES b/CHANGES
index 988da18a..a7f84cfa 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,6 @@
 12 October 2007
 
+* (nicm) Add a warning if $TMUX exists on new/attach.
 * (nicm) send-prefix command. Bound to C-b by default.
 * (nicm) set status, status-fg, status-bg commands. fg and bg are as a number
   from 0 to 8 or a string ("red", "blue", etc). status may be 1/0, on/off,
@@ -126,5 +127,5 @@
   (including mutt, emacs). No status bar yet and no key remapping or other
   customisation.
 
-$Id: CHANGES,v 1.40 2007-10-12 13:51:44 nicm Exp $
+$Id: CHANGES,v 1.41 2007-10-12 14:46:48 nicm Exp $
 
diff --git a/TODO b/TODO
index 631c2958..791bf519 100644
--- a/TODO
+++ b/TODO
@@ -57,5 +57,4 @@
 	kill window (C-b backsp)
 	kill session (no not bind by default)
 	set shell
-- handle tmux in tmux (check $TMUX and abort)
 - check for some reqd terminfo caps on startup
diff --git a/cmd-attach-session.c b/cmd-attach-session.c
index 18c388f3..0795a7ac 100644
--- a/cmd-attach-session.c
+++ b/cmd-attach-session.c
@@ -1,4 +1,4 @@
-/* $Id: cmd-attach-session.c,v 1.5 2007-10-04 22:04:01 nicm Exp $ */
+/* $Id: cmd-attach-session.c,v 1.6 2007-10-12 14:46:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -38,7 +38,7 @@ struct cmd_attach_session_data {
 
 const struct cmd_entry cmd_attach_session_entry = {
 	"attach-session", "attach", "[-d]",
-	0,
+	CMD_CANTNEST,
 	cmd_attach_session_parse,
 	cmd_attach_session_exec, 
 	cmd_attach_session_send,
diff --git a/cmd-new-session.c b/cmd-new-session.c
index dfc894f3..564aa909 100644
--- a/cmd-new-session.c
+++ b/cmd-new-session.c
@@ -1,4 +1,4 @@
-/* $Id: cmd-new-session.c,v 1.10 2007-10-04 22:04:01 nicm Exp $ */
+/* $Id: cmd-new-session.c,v 1.11 2007-10-12 14:46:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -40,7 +40,7 @@ struct cmd_new_session_data {
 
 const struct cmd_entry cmd_new_session_entry = {
 	"new-session", "new", "[-d] [-n session name] [command]",
-	CMD_STARTSERVER|CMD_NOSESSION,
+	CMD_STARTSERVER|CMD_NOSESSION|CMD_CANTNEST,
 	cmd_new_session_parse,
 	cmd_new_session_exec, 
 	cmd_new_session_send,
diff --git a/server-msg.c b/server-msg.c
index 41f4aa63..6fa574c8 100644
--- a/server-msg.c
+++ b/server-msg.c
@@ -1,4 +1,4 @@
-/* $Id: server-msg.c,v 1.25 2007-10-04 22:04:01 nicm Exp $ */
+/* $Id: server-msg.c,v 1.26 2007-10-12 14:46:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -123,6 +123,12 @@ server_msg_fn_command(struct hdr *hdr, struct client *c)
 	ctx.client = c;
 	ctx.flags = 0;
 
+	if (data.sid.pid != -1 && (cmd->entry->flags & CMD_CANTNEST)) {
+		server_msg_fn_command_error(&ctx, "sessions should be nested "
+		    "with care. unset $TMUX and retry to force");
+		return (0);
+	}
+
 	if (cmd->entry->flags & CMD_NOSESSION)
 		ctx.session = NULL;
 	else {
diff --git a/tmux.c b/tmux.c
index af28548c..17296af5 100644
--- a/tmux.c
+++ b/tmux.c
@@ -1,4 +1,4 @@
-/* $Id: tmux.c,v 1.30 2007-10-12 12:08:51 nicm Exp $ */
+/* $Id: tmux.c,v 1.31 2007-10-12 14:46:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -210,7 +210,8 @@ main(int argc, char **argv)
 		exit(1);
 	}
 
-	if (!(cmd->entry->flags & CMD_NOSESSION))
+	if (!(cmd->entry->flags & CMD_NOSESSION) ||
+	    (cmd->entry->flags & CMD_CANTNEST))
 		client_fill_sessid(&data.sid, name);
 	if (client_init(path, &cctx, cmd->entry->flags & CMD_STARTSERVER) != 0)
 		exit(1);
diff --git a/tmux.h b/tmux.h
index 8dfc8824..4461bbb5 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $Id: tmux.h,v 1.57 2007-10-12 13:51:44 nicm Exp $ */
+/* $Id: tmux.h,v 1.58 2007-10-12 14:46:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -470,6 +470,7 @@ struct cmd_entry {
 
 #define CMD_STARTSERVER 0x1
 #define CMD_NOSESSION 0x2
+#define CMD_CANTNEST 0x4
 	int		 flags;
 
 	int		 (*parse)(void **, int, char **, char **);