Restore code to handle wcwidth failure so that unknown codepoints still

do the most likely right thing. GitHub issue 3427, patch based on an
diff from Jesse Luehrs in GitHub issue 3003.

diff --git a/usr.bin/tmux/utf8.c b/usr.bin/tmux/utf8.c
index f54fad0..f6b6374 100644 (file)
--- a/usr.bin/tmux/utf8.c
+++ b/usr.bin/tmux/utf8.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: utf8.c,v 1.59 2022/12/16 08:19:58 nicm Exp $ */
+/* $OpenBSD: utf8.c,v 1.60 2023/01/08 22:15:30 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -226,9 +226,16 @@ utf8_width(struct utf8_data *ud, int *width)
        case 0:
                return (UTF8_ERROR);
        }
+       log_debug("UTF-8 %.*s is %08X", (int)ud->size, ud->data, (u_int)wc);
        *width = wcwidth(wc);
-       log_debug("UTF-8 %.*s %#x, wcwidth() %d", (int)ud->size, ud->data,
-           (u_int)wc, *width);
+       log_debug("wcwidth(%08X) returned %d", (u_int)wc, *width);
+       if (*width < 0) {
+               /*
+                * C1 control characters are nonprintable, so they are always
+                * zero width.
+                */
+               *width = (wc >= 0x80 && wc <= 0x9f) ? 0 : 1;
+       }
        if (*width >= 0 && *width <= 0xff)
                return (UTF8_DONE);
        return (UTF8_ERROR);