From 7d75dbbdda237f0d7551d47a903cd04a58b29d42 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicm@openbsd.org>
Date: Tue, 19 Jan 2010 21:27:47 +0000
Subject: [PATCH] Permit !, + and - to be used for window targets to specify
 last window (!), or next and previous window by number (+ and -).

Also tidy an if in cmd-new-window.c.
---
 cmd-new-window.c | 26 +++++++++-----------
 cmd.c            | 64 ++++++++++++++++++++++++++++++++++++++++++------
 tmux.1           |  7 ++++++
 3 files changed, 75 insertions(+), 22 deletions(-)

diff --git a/cmd-new-window.c b/cmd-new-window.c
index d7b59b8b..ea3cff4a 100644
--- a/cmd-new-window.c
+++ b/cmd-new-window.c
@@ -129,21 +129,19 @@ cmd_new_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 	wl = NULL;
 	if (idx != -1)
 		wl = winlink_find_by_index(&s->windows, idx);
-	if (wl != NULL) {
-		if (data->flag_kill) {
-			/*
-			 * Can't use session_detach as it will destroy session
-			 * if this makes it empty.
-			 */
-			session_alert_cancel(s, wl);
-			winlink_stack_remove(&s->lastw, wl);
-			winlink_remove(&s->windows, wl);
+	if (wl != NULL && data->flag_kill) {
+		/*
+		 * Can't use session_detach as it will destroy session if this
+		 * makes it empty.
+		 */
+		session_alert_cancel(s, wl);
+		winlink_stack_remove(&s->lastw, wl);
+		winlink_remove(&s->windows, wl);
 
-			/* Force select/redraw if current. */
-			if (wl == s->curw) {
-				data->flag_detached = 0;
-				s->curw = NULL;
-			}
+		/* Force select/redraw if current. */
+		if (wl == s->curw) {
+			data->flag_detached = 0;
+			s->curw = NULL;
 		}
 	}
 
diff --git a/cmd.c b/cmd.c
index 72fec848..6163d78a 100644
--- a/cmd.c
+++ b/cmd.c
@@ -702,11 +702,19 @@ cmd_find_window(struct cmd_ctx *ctx, const char *arg, struct session **sp)
 
 	/*
 	 * Then work out the window. An empty string is the current window,
-	 * otherwise try to look it up in the session.
+	 * otherwise try special cases then to look it up in the session.
 	 */
 	if (*winptr == '\0')
 		wl = s->curw;
-	else if ((wl = cmd_lookup_window(s, winptr, &ambiguous)) == NULL)
+	else if (winptr[0] == '!' && winptr[1] == '\0')
+		wl = TAILQ_FIRST(&s->lastw);
+	else if (winptr[0] == '+' && winptr[1] == '\0')
+		wl = winlink_next(s->curw);
+	else if (winptr[0] == '-' && winptr[1] == '\0')
+		wl = winlink_previous(s->curw);
+	else
+		wl = cmd_lookup_window(s, winptr, &ambiguous);
+	if (wl == NULL)
 		goto not_found;
 
 	if (sessptr != NULL)
@@ -714,8 +722,20 @@ cmd_find_window(struct cmd_ctx *ctx, const char *arg, struct session **sp)
 	return (wl);
 
 no_colon:
-	/* No colon in the string, first try as a window then as a session. */
-	if ((wl = cmd_lookup_window(s, arg, &ambiguous)) == NULL) {
+	/*
+	 * No colon in the string, first try special cases, then as a window
+	 * and lastly as a session.
+	 */
+	if (arg[0] == '!' && arg[1] == '\0') {
+		if ((wl = TAILQ_FIRST(&s->lastw)) == NULL)
+			goto not_found;
+	} else if (arg[0] == '+' && arg[1] == '\0') {
+		if ((wl = winlink_next(s->curw)) == NULL)
+			goto not_found;
+	} else if (arg[0] == '-' && arg[1] == '\0') {
+		if ((wl = winlink_previous(s->curw)) == NULL)
+			goto not_found;
+	} else if ((wl = cmd_lookup_window(s, arg, &ambiguous)) == NULL) {
 		if (ambiguous)
 			goto not_found;
 		if ((s = cmd_lookup_session(arg, &ambiguous)) == NULL)
@@ -757,6 +777,7 @@ int
 cmd_find_index(struct cmd_ctx *ctx, const char *arg, struct session **sp)
 {
 	struct session	*s;
+	struct winlink	*wl;
 	const char	*winptr;
 	char		*sessptr = NULL;
 	int		 idx, ambiguous = 0;
@@ -802,8 +823,20 @@ cmd_find_index(struct cmd_ctx *ctx, const char *arg, struct session **sp)
 	 * try to look it up in the session.
 	 */
 	if (*winptr == '\0')
-		 idx = -1;
-	else if ((idx = cmd_lookup_index(s, winptr, &ambiguous)) == -1) {
+		idx = -1;
+	else if (winptr[0] == '!' && winptr[1] == '\0') {
+		if ((wl = TAILQ_FIRST(&s->lastw)) == NULL)
+			goto not_found;
+		idx = wl->idx;
+	} else if (winptr[0] == '+' && winptr[1] == '\0') {
+		if (s->curw->idx == INT_MAX)
+			goto not_found;
+		idx = s->curw->idx + 1;
+	} else if (winptr[0] == '-' && winptr[1] == '\0') {
+		if (s->curw->idx == 0)
+			goto not_found;
+		idx = s->curw->idx - 1;
+	} else if ((idx = cmd_lookup_index(s, winptr, &ambiguous)) == -1) {
 		if (ambiguous)
 			goto not_found;
 		ctx->error(ctx, "invalid index: %s", arg);
@@ -815,8 +848,23 @@ cmd_find_index(struct cmd_ctx *ctx, const char *arg, struct session **sp)
 	return (idx);
 
 no_colon:
-	/* No colon in the string, first try as a window then as a session. */
-	if ((idx = cmd_lookup_index(s, arg, &ambiguous)) == -1) {
+	/*
+	 * No colon in the string, first try special cases, then as a window
+	 * and lastly as a session.
+	 */
+	if (arg[0] == '!' && arg[1] == '\0') {
+		if ((wl = TAILQ_FIRST(&s->lastw)) == NULL)
+			goto not_found;
+		idx = wl->idx;
+	} else if (arg[0] == '+' && arg[1] == '\0') {
+		if (s->curw->idx == INT_MAX)
+			goto not_found;
+		idx = s->curw->idx + 1;
+	} else if (arg[0] == '-' && arg[1] == '\0') {
+		if (s->curw->idx == 0)
+			goto not_found;
+		idx = s->curw->idx - 1;
+	} else if ((idx = cmd_lookup_index(s, arg, &ambiguous)) == -1) {
 		if (ambiguous)
 			goto not_found;
 		if ((s = cmd_lookup_session(arg, &ambiguous)) == NULL)
diff --git a/tmux.1 b/tmux.1
index 409b6bb0..befc0cc8 100644
--- a/tmux.1
+++ b/tmux.1
@@ -307,6 +307,13 @@ commands)
 otherwise the current window in
 .Em session
 is chosen.
+The special character
+.Ql \&!
+uses the last (previously current) window, or
+.Ql +
+and
+.Ql -
+are the next window or the previous window by number.
 When the argument does not contain a colon,
 .Nm
 first attempts to parse it as window; if that fails, an attempt is made to