From 5107e848977640398843e720e26d45a66954e7f9 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Wed, 21 Apr 2021 09:32:48 +0100
Subject: [PATCH] Add an "always" value to the extended-keys option to always
 forward these keys to applications inside tmux.

---
 input.c         |  2 ++
 options-table.c |  6 +++++-
 screen.c        |  4 +++-
 tmux.1          | 21 +++++++++++++++++----
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/input.c b/input.c
index f6aeb027..b599f27d 100644
--- a/input.c
+++ b/input.c
@@ -1390,6 +1390,8 @@ input_csi_dispatch(struct input_ctx *ictx)
 	case INPUT_CSI_MODSET:
 		n = input_get(ictx, 0, 0, 0);
 		m = input_get(ictx, 1, 0, 0);
+		if (options_get_number(global_options, "extended-keys") == 2)
+			break;
 		if (n == 0 || (n == 4 && m == 0))
 			screen_write_mode_clear(sctx, MODE_KEXTENDED);
 		else if (n == 4 && (m == 1 || m == 2))
diff --git a/options-table.c b/options-table.c
index b185969c..8264d1b7 100644
--- a/options-table.c
+++ b/options-table.c
@@ -74,6 +74,9 @@ static const char *options_table_remain_on_exit_list[] = {
 static const char *options_table_detach_on_destroy_list[] = {
 	"off", "on", "no-detached", NULL
 };
+static const char *options_table_extended_keys_list[] = {
+	"off", "on", "always", NULL
+};
 
 /* Status line format. */
 #define OPTIONS_TABLE_STATUS_FORMAT1 \
@@ -266,8 +269,9 @@ const struct options_table_entry options_table[] = {
 	},
 
 	{ .name = "extended-keys",
-	  .type = OPTIONS_TABLE_FLAG,
+	  .type = OPTIONS_TABLE_CHOICE,
 	  .scope = OPTIONS_TABLE_SERVER,
+	  .choices = options_table_extended_keys_list,
 	  .default_num = 0,
 	  .text = "Whether to request extended key sequences from terminals "
 	          "that support it."
diff --git a/screen.c b/screen.c
index 2b9d70de..2b83c285 100644
--- a/screen.c
+++ b/screen.c
@@ -100,7 +100,9 @@ screen_reinit(struct screen *s)
 	s->rupper = 0;
 	s->rlower = screen_size_y(s) - 1;
 
-	s->mode = MODE_CURSOR | MODE_WRAP;
+	s->mode = MODE_CURSOR|MODE_WRAP;
+	if (options_get_number(global_options, "extended-keys") == 2)
+		s->mode |= MODE_KEXTENDED;
 
 	if (s->saved_grid != NULL)
 		screen_alternate_off(s, NULL, 0);
diff --git a/tmux.1 b/tmux.1
index c4fc06ba..6967c769 100644
--- a/tmux.1
+++ b/tmux.1
@@ -3418,11 +3418,24 @@ sessions.
 .Xc
 If enabled, the server will exit when there are no attached clients.
 .It Xo Ic extended-keys
-.Op Ic on | off
+.Op Ic on | off | always
 .Xc
-When enabled, extended keys are requested from the terminal and if supported
-are recognised by
-.Nm .
+When
+.Ic on
+or
+.Ic always ,
+the escape sequence to enable extended keys is sent to the terminal, if
+.Nm
+knows that it is supported.
+.Nm
+always recognises extended keys itself.
+If this option is
+.Ic on ,
+.Nm
+will only forward extended keys to applications when they request them; if
+.Ic always ,
+.Nm
+will always forward the keys.
 .It Xo Ic focus-events
 .Op Ic on | off
 .Xc