Add a UTF-8 aware string length function and make UTF-8 in

status-left/status-right work properly. At the moment any top-bit-set
characters are assumed to be UTF-8: a status-utf8 option to configure this will
come shortly.

screen-write.c

@@ -52,20 +52,126 @@ screen_write_putc(
 	screen_write_cell(ctx, gc, NULL);
 }
 
+/* Calculate string length. */
+size_t printflike1
+screen_write_strlen(const char *fmt, ...)
+{
+	va_list	ap;
+	char   *msg;
+	u_char *ptr, utf8buf[4];
+	size_t	left, size = 0;
+
+	va_start(ap, fmt);
+	xvasprintf(&msg, fmt, ap);
+	va_end(ap);
+
+	ptr = msg;
+	while (*ptr != '\0') {
+		if (*ptr > 0x7f) {	/* Assume this is UTF-8. */
+			memset(utf8buf, 0xff, sizeof utf8buf);
+
+			left = strlen(ptr);
+			if (*ptr >= 0xc2 && *ptr <= 0xdf && left >= 2) {
+				memcpy(utf8buf, ptr, 2);
+				ptr += 2;
+			} else if (*ptr >= 0xe0 && *ptr <= 0xef && left >= 3) {
+				memcpy(utf8buf, ptr, 3);
+				ptr += 3;
+			} else if (*ptr >= 0xf0 && *ptr <= 0xf4 && left >= 4) {
+				memcpy(utf8buf, ptr, 4);
+				ptr += 4;
+			} else {
+				*utf8buf = *ptr;
+				ptr++;
+			}
+			size += utf8_width(utf8buf);
+		} else {
+			size++;
+			ptr++;
+		}
+	}	
+
+	return (size);
+}
+
 /* Write string. */
 void printflike3
 screen_write_puts(
     struct screen_write_ctx *ctx, struct grid_cell *gc, const char *fmt, ...)
 {
 	va_list	ap;
-	char   *msg, *ptr;
 
 	va_start(ap, fmt);
-	xvasprintf(&msg, fmt, ap);
+	screen_write_vnputs(ctx, -1, gc, fmt, ap);
 	va_end(ap);
+}
 
-	for (ptr = msg; *ptr != '\0'; ptr++)
+/* Write string with length limit (-1 for unlimited). */
-		screen_write_putc(ctx, gc, (u_char) *ptr);
+void printflike4
+screen_write_nputs(struct screen_write_ctx *ctx,
+    ssize_t maxlen, struct grid_cell *gc, const char *fmt, ...)
+{
+	va_list	ap;
+
+	va_start(ap, fmt);
+	screen_write_vnputs(ctx, maxlen, gc, fmt, ap);
+	va_end(ap);
+}
+
+void
+screen_write_vnputs(struct screen_write_ctx *ctx,
+    ssize_t maxlen, struct grid_cell *gc, const char *fmt, va_list ap)
+{
+	char   *msg;
+	u_char *ptr, utf8buf[4];
+	size_t	left, size = 0;
+	int	width;
+
+	xvasprintf(&msg, fmt, ap);
+
+	ptr = msg;
+	while (*ptr != '\0') {
+		if (*ptr > 0x7f) {	/* Assume this is UTF-8. */
+			memset(utf8buf, 0xff, sizeof utf8buf);
+
+			left = strlen(ptr);
+			if (*ptr >= 0xc2 && *ptr <= 0xdf && left >= 2) {
+				memcpy(utf8buf, ptr, 2);
+				ptr += 2;
+			} else if (*ptr >= 0xe0 && *ptr <= 0xef && left >= 3) {
+				memcpy(utf8buf, ptr, 3);
+				ptr += 3;
+			} else if (*ptr >= 0xf0 && *ptr <= 0xf4 && left >= 4) {
+				memcpy(utf8buf, ptr, 4);
+				ptr += 4;
+			} else {
+				*utf8buf = *ptr;
+				ptr++;
+			}
+			
+			width = utf8_width(utf8buf);
+			if (maxlen > 0 && size + width > (size_t) maxlen) {
+				while (size < (size_t) maxlen) {
+					screen_write_putc(ctx, gc, ' ');
+					size++;
+				}
+				break;
+			}
+			size += width;
+
+			gc->flags |= GRID_FLAG_UTF8;
+			screen_write_cell(ctx, gc, utf8buf);
+			gc->flags &= ~GRID_FLAG_UTF8;
+
+		} else {
+			if (maxlen > 0 && size > (size_t) maxlen)
+				break;
+
+			size++;
+			screen_write_putc(ctx, gc, *ptr);
+			ptr++;
+		}
+	}
 
 	xfree(msg);
 }

status.c

@@ -47,8 +47,8 @@ status_redraw(struct client *c)
 	struct window_pane	       *wp;
 	struct screen		       *sc = NULL, old_status;
 	char		 	       *left, *right, *text, *ptr;
-	size_t				llen, rlen, offset, xx, yy, sy;
+	size_t				llen, llen2, rlen, rlen2, offset;
-	size_t				size, start, width;
+	size_t				xx, yy, sy, size, start, width;
 	struct grid_cell	        stdgc, gc;
 	int				larrow, rarrow;
 
@@ -78,15 +78,16 @@ status_redraw(struct client *c)
 	left = status_replace(s, options_get_string(
 	    &s->options, "status-left"), c->status_timer.tv_sec);
 	llen = options_get_number(&s->options, "status-left-length");
-	if (strlen(left) < llen)
+	llen2 = screen_write_strlen("%s", left);
-		llen = strlen(left);
+	if (llen2 < llen)
-	left[llen] = '\0';
+		llen = llen2;
 
 	right = status_replace(s, options_get_string(
 	    &s->options, "status-right"), c->status_timer.tv_sec);
 	rlen = options_get_number(&s->options, "status-right-length");
-	if (strlen(right) < rlen)
+	rlen2 = screen_write_strlen("%s", right);
-		rlen = strlen(right);
+	if (rlen2 < rlen)
+		rlen = rlen2;
 	right[rlen] = '\0';
 
 	/*
@@ -163,7 +164,7 @@ draw:
 	screen_write_start(&ctx, NULL, &c->status);
 	if (llen != 0) {
  		screen_write_cursormove(&ctx, 0, yy);
-		screen_write_puts(&ctx, &stdgc, "%s ", left);
+		screen_write_nputs(&ctx, llen + 1, &stdgc, "%s ", left);
 		if (larrow)
 			screen_write_putc(&ctx, &stdgc, ' ');
 	} else {
@@ -220,7 +221,7 @@ draw:
 	/* Draw the last item. */
 	if (rlen != 0) {
 		screen_write_cursormove(&ctx, c->tty.sx - rlen - 1, yy);
-		screen_write_puts(&ctx, &stdgc, " %s", right);
+		screen_write_nputs(&ctx, rlen + 1, &stdgc, " %s", right);
 	}
 
 	/* Draw the arrows. */

tmux.h

@@ -1347,8 +1347,13 @@ void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int);
 void	 screen_write_start(
     	     struct screen_write_ctx *, struct window_pane *, struct screen *);
 void	 screen_write_stop(struct screen_write_ctx *);
-void printflike3 screen_write_puts(
+size_t printflike1 screen_write_strlen(const char *, ...);
-	     struct screen_write_ctx *, struct grid_cell *, const char *, ...);
+void printflike3 screen_write_puts(struct screen_write_ctx *,
+    	     struct grid_cell *, const char *, ...);
+void printflike4 screen_write_nputs(struct screen_write_ctx *,
+    	     ssize_t, struct grid_cell *, const char *, ...);
+void	 screen_write_vnputs(struct screen_write_ctx *,
+    	     ssize_t, struct grid_cell *, const char *, va_list);
 void	 screen_write_putc(
     	     struct screen_write_ctx *, struct grid_cell *, u_char);
 void	 screen_write_copy(struct screen_write_ctx *,