From df3ab87964fc52c6f44b2bbe014c8bec202d0528 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Wed, 22 Mar 2017 07:16:54 +0000
Subject: [PATCH] Add support for the strikethrough attribute (SGR 9), using
 the new smxx terminfo capability. This means there are now nine attribute
 bits, so anything above 0xff uses an extended cell.

---
 attributes.c | 11 +++++++----
 grid.c       |  5 ++++-
 input.c      |  6 ++++++
 style.c      |  4 +---
 tmux.1       |  3 ++-
 tmux.h       |  8 +++++---
 tty-term.c   |  1 +
 tty.c        |  4 +++-
 8 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/attributes.c b/attributes.c
index 046cdcc5..1e45e584 100644
--- a/attributes.c
+++ b/attributes.c
@@ -23,7 +23,7 @@
 #include "tmux.h"
 
 const char *
-attributes_tostring(u_char attr)
+attributes_tostring(int attr)
 {
 	static char	buf[128];
 	size_t		len;
@@ -31,14 +31,15 @@ attributes_tostring(u_char attr)
 	if (attr == 0)
 		return ("none");
 
-	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s",
+	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s%s",
 	    (attr & GRID_ATTR_BRIGHT) ? "bright," : "",
 	    (attr & GRID_ATTR_DIM) ? "dim," : "",
 	    (attr & GRID_ATTR_UNDERSCORE) ? "underscore," : "",
 	    (attr & GRID_ATTR_BLINK)? "blink," : "",
 	    (attr & GRID_ATTR_REVERSE) ? "reverse," : "",
 	    (attr & GRID_ATTR_HIDDEN) ? "hidden," : "",
-	    (attr & GRID_ATTR_ITALICS) ? "italics," : "");
+	    (attr & GRID_ATTR_ITALICS) ? "italics," : "",
+	    (attr & GRID_ATTR_STRIKETHROUGH) ? "strikethrough," : "");
 	if (len > 0)
 		buf[len - 1] = '\0';
 
@@ -49,7 +50,7 @@ int
 attributes_fromstring(const char *str)
 {
 	const char	delimiters[] = " ,|";
-	u_char		attr;
+	int		attr;
 	size_t		end;
 
 	if (*str == '\0' || strcspn(str, delimiters) == 0)
@@ -78,6 +79,8 @@ attributes_fromstring(const char *str)
 			attr |= GRID_ATTR_HIDDEN;
 		else if (end == 7 && strncasecmp(str, "italics", end) == 0)
 			attr |= GRID_ATTR_ITALICS;
+		else if (end == 13 && strncasecmp(str, "strikethrough", end) == 0)
+			attr |= GRID_ATTR_STRIKETHROUGH;
 		else
 			return (-1);
 		str += end + strspn(str + end, delimiters);
diff --git a/grid.c b/grid.c
index 424d272a..43145eae 100644
--- a/grid.c
+++ b/grid.c
@@ -85,6 +85,8 @@ grid_need_extended_cell(const struct grid_cell_entry *gce,
 {
 	if (gce->flags & GRID_FLAG_EXTENDED)
 		return (1);
+	if (gc->attr > 0xff)
+		return (1);
 	if (gc->data.size != 1 || gc->data.width != 1)
 		return (1);
 	if ((gc->fg & COLOUR_FLAG_RGB) ||(gc->bg & COLOUR_FLAG_RGB))
@@ -687,7 +689,8 @@ grid_string_cells_code(const struct grid_cell *lastgc,
 		{ GRID_ATTR_UNDERSCORE, 4 },
 		{ GRID_ATTR_BLINK, 5 },
 		{ GRID_ATTR_REVERSE, 7 },
-		{ GRID_ATTR_HIDDEN, 8 }
+		{ GRID_ATTR_HIDDEN, 8 },
+		{ GRID_ATTR_STRIKETHROUGH, 9 }
 	};
 	n = 0;
 
diff --git a/input.c b/input.c
index 0e71f656..0b667390 100644
--- a/input.c
+++ b/input.c
@@ -1764,6 +1764,9 @@ input_csi_dispatch_sgr(struct input_ctx *ictx)
 		case 8:
 			gc->attr |= GRID_ATTR_HIDDEN;
 			break;
+		case 9:
+			gc->attr |= GRID_ATTR_STRIKETHROUGH;
+			break;
 		case 22:
 			gc->attr &= ~(GRID_ATTR_BRIGHT|GRID_ATTR_DIM);
 			break;
@@ -1782,6 +1785,9 @@ input_csi_dispatch_sgr(struct input_ctx *ictx)
 		case 28:
 			gc->attr &= ~GRID_ATTR_HIDDEN;
 			break;
+		case 29:
+			gc->attr &= ~GRID_ATTR_STRIKETHROUGH;
+			break;
 		case 30:
 		case 31:
 		case 32:
diff --git a/style.c b/style.c
index cec1b894..6e78b3a9 100644
--- a/style.c
+++ b/style.c
@@ -31,10 +31,8 @@ style_parse(const struct grid_cell *defgc, struct grid_cell *gc,
 	struct grid_cell	savedgc;
 	const char		delimiters[] = " ,";
 	char			tmp[32];
-	int			val;
+	int			val, fg, bg, attr, flags;
 	size_t			end;
-	int			fg, bg;
-	u_char			attr, flags;
 
 	if (*in == '\0')
 		return (0);
diff --git a/tmux.1 b/tmux.1
index a43726e9..6d035573 100644
--- a/tmux.1
+++ b/tmux.1
@@ -2664,8 +2664,9 @@ or a comma-delimited list of one or more of:
 .Ic blink ,
 .Ic reverse ,
 .Ic hidden ,
-or
 .Ic italics ,
+or
+.Ic strikethrough
 to turn an attribute on, or an attribute prefixed with
 .Ql no
 to turn one off.
diff --git a/tmux.h b/tmux.h
index fa7ef636..dab15b3a 100644
--- a/tmux.h
+++ b/tmux.h
@@ -395,6 +395,7 @@ enum tty_code_code {
 	TTYC_SMKX,	/* keypad_xmit, ks */
 	TTYC_SMSO,	/* enter_standout_mode, so */
 	TTYC_SMUL,	/* enter_underline_mode, us */
+	TTYC_SMXX,
 	TTYC_SS,	/* set cursor style, Ss */
 	TTYC_TC,	/* 24-bit "true" colour, Tc */
 	TTYC_TSL,	/* to_status_line, tsl */
@@ -506,7 +507,7 @@ enum utf8_state {
 #define COLOUR_FLAG_256 0x01000000
 #define COLOUR_FLAG_RGB 0x02000000
 
-/* Grid attributes. */
+/* Grid attributes. Anything above 0xff is stored in an extended cell. */
 #define GRID_ATTR_BRIGHT 0x1
 #define GRID_ATTR_DIM 0x2
 #define GRID_ATTR_UNDERSCORE 0x4
@@ -515,6 +516,7 @@ enum utf8_state {
 #define GRID_ATTR_HIDDEN 0x20
 #define GRID_ATTR_ITALICS 0x40
 #define GRID_ATTR_CHARSET 0x80	/* alternative character set */
+#define GRID_ATTR_STRIKETHROUGH 0x100
 
 /* Grid flags. */
 #define GRID_FLAG_FG256 0x1
@@ -531,7 +533,7 @@ enum utf8_state {
 /* Grid cell data. */
 struct grid_cell {
 	u_char			flags;
-	u_char			attr;
+	u_short			attr;
 	int			fg;
 	int			bg;
 	struct utf8_data	data;
@@ -1909,7 +1911,7 @@ int	 colour_fromstring(const char *s);
 u_char	 colour_256to16(u_char);
 
 /* attributes.c */
-const char *attributes_tostring(u_char);
+const char *attributes_tostring(int);
 int	 attributes_fromstring(const char *);
 
 /* grid.c */
diff --git a/tty-term.c b/tty-term.c
index 2065e09f..df01d5de 100644
--- a/tty-term.c
+++ b/tty-term.c
@@ -249,6 +249,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_SMKX] = { TTYCODE_STRING, "smkx" },
 	[TTYC_SMSO] = { TTYCODE_STRING, "smso" },
 	[TTYC_SMUL] = { TTYCODE_STRING, "smul" },
+	[TTYC_SMXX] =  { TTYCODE_STRING, "smxx" },
 	[TTYC_SS] = { TTYCODE_STRING, "Ss" },
 	[TTYC_TC] = { TTYCODE_FLAG, "Tc" },
 	[TTYC_TSL] = { TTYCODE_STRING, "tsl" },
diff --git a/tty.c b/tty.c
index 03e4686b..8792da70 100644
--- a/tty.c
+++ b/tty.c
@@ -1557,7 +1557,7 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
     const struct window_pane *wp)
 {
 	struct grid_cell	*tc = &tty->cell, gc2;
-	u_char			 changed;
+	int			 changed;
 
 	/* Ignore cell if it is the same as the last one. */
 	if (wp != NULL &&
@@ -1627,6 +1627,8 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
 	}
 	if (changed & GRID_ATTR_HIDDEN)
 		tty_putcode(tty, TTYC_INVIS);
+	if (changed & GRID_ATTR_STRIKETHROUGH)
+		tty_putcode(tty, TTYC_SMXX);
 	if ((changed & GRID_ATTR_CHARSET) && tty_use_acs(tty))
 		tty_putcode(tty, TTYC_SMACS);
 }