From ec89eb955236f91e63febe1764123e605641fc52 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicm@openbsd.org>
Date: Wed, 6 Apr 2011 21:51:31 +0000
Subject: [PATCH] Change so that an empty session name always means the current
 sessions even if given with, for example, -t '', and explicitly forbid empty
 session names and those containing a : when they are created.

---
 cmd-new-session.c    | 12 +++++++++---
 cmd-rename-session.c |  4 ++++
 cmd.c                | 10 ++++++++--
 session.c            |  7 +++++++
 tmux.h               |  1 +
 5 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/cmd-new-session.c b/cmd-new-session.c
index fc847bd2..5eaa5393 100644
--- a/cmd-new-session.c
+++ b/cmd-new-session.c
@@ -68,9 +68,15 @@ cmd_new_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 	u_int			 sx, sy, i;
 
 	newname = args_get(args, 's');
-	if (newname != NULL && session_find(newname) != NULL) {
-		ctx->error(ctx, "duplicate session: %s", newname);
-		return (-1);
+	if (newname != NULL) {
+		if (!session_check_name(newname)) {
+			ctx->error(ctx, "bad session name: %s", newname);
+			return (-1);
+		}
+		if (session_find(newname) != NULL) {
+			ctx->error(ctx, "duplicate session: %s", newname);
+			return (-1);
+		}
 	}
 
 	target = args_get(args, 't');
diff --git a/cmd-rename-session.c b/cmd-rename-session.c
index 018e537f..cbda700f 100644
--- a/cmd-rename-session.c
+++ b/cmd-rename-session.c
@@ -46,6 +46,10 @@ cmd_rename_session_exec(struct cmd *self, struct cmd_ctx *ctx)
 	const char	*newname;
 
 	newname = args->argv[0];
+	if (!session_check_name(newname)) {
+		ctx->error(ctx, "bad session name: %s", newname);
+		return (-1);
+	}
 	if (session_find(newname) != NULL) {
 		ctx->error(ctx, "duplicate session: %s", newname);
 		return (-1);
diff --git a/cmd.c b/cmd.c
index ac66f6e8..ee893a25 100644
--- a/cmd.c
+++ b/cmd.c
@@ -725,6 +725,12 @@ cmd_find_session(struct cmd_ctx *ctx, const char *arg, int prefer_unattached)
 	if (arglen != 0 && tmparg[arglen - 1] == ':')
 		tmparg[arglen - 1] = '\0';
 
+	/* An empty session name is the current session. */
+	if (*tmparg == '\0') {
+		xfree (tmparg);
+		return (cmd_current_session(ctx, prefer_unattached));
+	}
+
 	/* Find the session, if any. */
 	s = cmd_lookup_session(tmparg, &ambiguous);
 
@@ -840,7 +846,7 @@ no_colon:
 lookup_session:
 	if (ambiguous)
 		goto not_found;
-	if ((s = cmd_lookup_session(arg, &ambiguous)) == NULL)
+	if (*arg != '\0' && (s = cmd_lookup_session(arg, &ambiguous)) == NULL)
 		goto no_session;
 
 	if (sp != NULL)
@@ -981,7 +987,7 @@ no_colon:
 lookup_session:
 	if (ambiguous)
 		goto not_found;
-	if ((s = cmd_lookup_session(arg, &ambiguous)) == NULL)
+	if (*arg != '\0' && (s = cmd_lookup_session(arg, &ambiguous)) == NULL)
 		goto no_session;
 
 	if (sp != NULL)
diff --git a/session.c b/session.c
index 9babd81c..e9bffed2 100644
--- a/session.c
+++ b/session.c
@@ -164,6 +164,13 @@ session_destroy(struct session *s)
 	RB_INSERT(sessions, &dead_sessions, s);
 }
 
+/* Check a session name is valid: not empty and no colons. */
+int
+session_check_name(const char *name)
+{
+	return (*name != '\0' && strchr(name, ':') == NULL);
+}
+
 /* Update session active time. */
 void
 session_update_activity(struct session *s)
diff --git a/tmux.h b/tmux.h
index a2af2a87..12f68085 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1978,6 +1978,7 @@ struct session	*session_create(const char *, const char *, const char *,
 		     struct environ *, struct termios *, int, u_int, u_int,
 		     char **);
 void		 session_destroy(struct session *);
+int		 session_check_name(const char *);
 void		 session_update_activity(struct session *);
 struct session	*session_next_session(struct session *);
 struct session	*session_previous_session(struct session *);
-- 
2.11.4.GIT