Add a terminal feature for enable/disable extended keys (supported by xterm and

mintty) and add an option to make tmux send it.

options-table.c

@@ -251,6 +251,14 @@ const struct options_table_entry options_table[] = {
 		  "clients."
 	},
 
+	{ .name = "extended-keys",
+	  .type = OPTIONS_TABLE_FLAG,
+	  .scope = OPTIONS_TABLE_SERVER,
+	  .default_num = 0,
+	  .text = "Whether to request extended key sequences from terminals "
+	          "that support it."
+	},
+
 	{ .name = "focus-events",
 	  .type = OPTIONS_TABLE_FLAG,
 	  .scope = OPTIONS_TABLE_SERVER,

tmux.1

@@ -3225,6 +3225,12 @@ sessions.
 .Op Ic on | off
 .Xc
 If enabled, the server will exit when there are no attached clients.
+.It Xo Ic extended-keys
+.Op Ic on | off
+.Xc
+When enabled, extended keys are requested from the terminal and if supported
+are recognised by
+.Nm .
 .It Xo Ic focus-events
 .Op Ic on | off
 .Xc
@@ -5744,6 +5750,8 @@ Disable and enable bracketed paste.
 These are set automatically if the
 .Em XT
 capability is present.
+.It Em \&Dseks , \&Eneks
+Disable and enable extended keys.
 .It Em \&Dsfcs , \&Enfcs
 Disable and enable focus reporting.
 These are set automatically if the

tmux.h

@@ -292,6 +292,7 @@ enum tty_code_code {
 	TTYC_DL,
 	TTYC_DL1,
 	TTYC_DSBP,
+	TTYC_DSEKS,
 	TTYC_DSFCS,
 	TTYC_DSMG,
 	TTYC_E3,
@@ -301,6 +302,7 @@ enum tty_code_code {
 	TTYC_EL1,
 	TTYC_ENACS,
 	TTYC_ENBP,
+	TTYC_ENEKS,
 	TTYC_ENFCS,
 	TTYC_ENMG,
 	TTYC_FSL,
@@ -1286,7 +1288,7 @@ struct tty {
 /* 0x8 unused */
 #define TTY_STARTED 0x10
 #define TTY_OPENED 0x20
-#define TTY_FOCUS 0x40
+/* 0x40 unused */
 #define TTY_BLOCK 0x80
 #define TTY_HAVEDA 0x100
 #define TTY_HAVEXDA 0x200

tty-features.c

@@ -190,6 +190,18 @@ static const struct tty_feature tty_feature_sync = {
 	0
 };
 
+/* Terminal supports extended keys. */
+static const char *tty_feature_extkeys_capabilities[] = {
+	"Eneks=\\E[>4;1m",
+	"Dseks=\\E[>4m",
+	NULL
+};
+static const struct tty_feature tty_feature_extkeys = {
+	"extkeys",
+	tty_feature_extkeys_capabilities,
+	0
+};
+
 /* Terminal supports DECSLRM margins. */
 static const char *tty_feature_margins_capabilities[] = {
 	"Enmg=\\E[?69h",
@@ -218,6 +230,7 @@ static const struct tty_feature *tty_features[] = {
 	&tty_feature_ccolour,
 	&tty_feature_clipboard,
 	&tty_feature_cstyle,
+	&tty_feature_extkeys,
 	&tty_feature_focus,
 	&tty_feature_margins,
 	&tty_feature_overline,
@@ -321,7 +334,7 @@ tty_default_features(int *feat, const char *name, u_int version)
 	} table[] = {
 #define TTY_FEATURES_BASE_MODERN_XTERM "256,RGB,bpaste,clipboard,strikethrough,title"
 		{ .name = "mintty",
-		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",ccolour,cstyle,margins,overline"
+		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",ccolour,cstyle,extkeys,margins,overline"
 		},
 		{ .name = "tmux",
 		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",ccolour,cstyle,focus,overline,usstyle"
@@ -333,7 +346,7 @@ tty_default_features(int *feat, const char *name, u_int version)
 		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",cstyle,margins,sync"
 		},
 		{ .name = "XTerm",
-		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",ccolour,cstyle,focus,margins,rectfill"
+		  .features = TTY_FEATURES_BASE_MODERN_XTERM ",ccolour,cstyle,extkeys,focus,margins,rectfill"
 		}
 	};
 	u_int	i;

tty-term.c

@@ -86,6 +86,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_DIM] = { TTYCODE_STRING, "dim" },
 	[TTYC_DL1] = { TTYCODE_STRING, "dl1" },
 	[TTYC_DL] = { TTYCODE_STRING, "dl" },
+	[TTYC_DSEKS] = { TTYCODE_STRING, "Dseks" },
 	[TTYC_DSFCS] = { TTYCODE_STRING, "Dsfcs" },
 	[TTYC_DSBP] = { TTYCODE_STRING, "Dsbp" },
 	[TTYC_DSMG] = { TTYCODE_STRING, "Dsmg" },
@@ -96,6 +97,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_EL] = { TTYCODE_STRING, "el" },
 	[TTYC_ENACS] = { TTYCODE_STRING, "enacs" },
 	[TTYC_ENBP] = { TTYCODE_STRING, "Enbp" },
+	[TTYC_ENEKS] = { TTYCODE_STRING, "Eneks" },
 	[TTYC_ENFCS] = { TTYCODE_STRING, "Enfcs" },
 	[TTYC_ENMG] = { TTYCODE_STRING, "Enmg" },
 	[TTYC_FSL] = { TTYCODE_STRING, "fsl" },

tty.c

@@ -329,10 +329,10 @@ tty_start_tty(struct tty *tty)
 		tty_puts(tty, "\033[?1006l\033[?1005l");
 	}
 
-	if (options_get_number(global_options, "focus-events")) {
+	if (options_get_number(global_options, "focus-events"))
-		tty->flags |= TTY_FOCUS;
 		tty_raw(tty, tty_term_string(tty->term, TTYC_ENFCS));
-	}
+	if (options_get_number(global_options, "extended-keys"))
+		tty_raw(tty, tty_term_string(tty->term, TTYC_ENEKS));
 	if (tty->term->flags & TERM_VT100LIKE)
 		tty_puts(tty, "\033[?7727h");
 
@@ -415,12 +415,10 @@ tty_stop_tty(struct tty *tty)
 		tty_raw(tty, "\033[?1006l\033[?1005l");
 	}
 
-	if (tty->flags & TTY_FOCUS) {
-		tty->flags &= ~TTY_FOCUS;
-		tty_raw(tty, tty_term_string(tty->term, TTYC_DSFCS));
-	}
 	if (tty->term->flags & TERM_VT100LIKE)
 		tty_raw(tty, "\033[?7727l");
+	tty_raw(tty, tty_term_string(tty->term, TTYC_DSFCS));
+	tty_raw(tty, tty_term_string(tty->term, TTYC_DSEKS));
 
 	if (tty_use_margin(tty))
 		tty_raw(tty, tty_term_string(tty->term, TTYC_DSMG));