Add an attribute for ACS.

attributes.c

@@ -31,7 +31,8 @@ attributes_tostring(int attr)
 	if (attr == 0)
 		return ("none");
 
-	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s%s%s%s%s%s%s",
+	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+	    (attr & GRID_ATTR_CHARSET) ? "acs," : "",
 	    (attr & GRID_ATTR_BRIGHT) ? "bright," : "",
 	    (attr & GRID_ATTR_DIM) ? "dim," : "",
 	    (attr & GRID_ATTR_UNDERSCORE) ? "underscore," : "",
@@ -62,6 +63,7 @@ attributes_fromstring(const char *str)
 		const char	*name;
 		int		 attr;
 	} table[] = {
+		{ "acs", GRID_ATTR_CHARSET },
 		{ "bright", GRID_ATTR_BRIGHT },
 		{ "bold", GRID_ATTR_BRIGHT },
 		{ "dim", GRID_ATTR_DIM },

style.c

@@ -26,7 +26,7 @@
 #include "tmux.h"
 
 /* Mask for bits not included in style. */
-#define STYLE_ATTR_MASK (~GRID_ATTR_CHARSET)
+#define STYLE_ATTR_MASK (~0)
 
 /* Default style. */
 static struct style style_default = {
@@ -247,7 +247,7 @@ style_tostring(struct style *sy)
 		    colour_tostring(gc->bg));
 		comma = ",";
 	}
-	if (gc->attr != 0 && gc->attr != GRID_ATTR_CHARSET) {
+	if (gc->attr != 0) {
 		xsnprintf(s + off, sizeof s - off, "%s%s", comma,
 		    attributes_tostring(gc->attr));
 		comma = ",";

tmux.1

@@ -4661,7 +4661,8 @@ for the terminal default colour; or a hexadecimal RGB string such as
 Set the background colour.
 .It Ic none
 Set no attributes (turn off any active attributes).
-.It Xo Ic bright
+.It Xo Ic acs ,
+.Ic bright
 (or
 .Ic bold ) ,
 .Ic dim ,
@@ -4681,6 +4682,8 @@ Set an attribute.
 Any of the attributes may be prefixed with
 .Ql no
 to unset.
+.Ic acs
+is the terminal alternate character set.
 .It Xo Ic align=left
 (or
 .Ic noalign ) ,