[src/trunk]: src/lib/libcurses Fix handling of the tab special character.

[blymn <blymn%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/98acb16dcb16
branches:  trunk
changeset: 1026293:98acb16dcb16
user:      blymn <blymn%NetBSD.org@localhost>
date:      Tue Nov 16 21:00:50 2021 +0000

description:
Fix handling of the tab special character.

diffstat:

 lib/libcurses/ins_wstr.c |  29 ++++++++++++++++-------------
 1 files changed, 16 insertions(+), 13 deletions(-)

diffs (59 lines):

diff -r deb2619ee908 -r 98acb16dcb16 lib/libcurses/ins_wstr.c
--- a/lib/libcurses/ins_wstr.c  Tue Nov 16 20:42:47 2021 +0000
+++ b/lib/libcurses/ins_wstr.c  Tue Nov 16 21:00:50 2021 +0000
@@ -1,4 +1,4 @@
-/*   $NetBSD: ins_wstr.c,v 1.18 2021/11/15 06:27:06 blymn Exp $ */
+/*   $NetBSD: ins_wstr.c,v 1.19 2021/11/16 21:00:50 blymn Exp $ */
 
 /*
  * Copyright (c) 2005 The NetBSD Foundation Inc.
@@ -36,7 +36,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: ins_wstr.c,v 1.18 2021/11/15 06:27:06 blymn Exp $");
+__RCSID("$NetBSD: ins_wstr.c,v 1.19 2021/11/16 21:00:50 blymn Exp $");
 #endif                                           /* not lint */
 
 #include <string.h>
@@ -194,9 +194,12 @@
                                continue;
 
                        case L'\t':
-                               w = min(win->maxx - x, TABSIZE - (x % TABSIZE));
-                               width += w * wcwidth(ws[0]);
-                               x += w * wcwidth(ws[0]);
+                               cw = wcwidth(ws[0]);
+                               if (cw < 0)
+                                       cw = 1;
+                               w = cw * (TABSIZE - (x % TABSIZE));
+                               width += w;
+                               x += w;
                                scp++;
                                continue;
                }
@@ -254,16 +257,16 @@
                                        break;
 
                                case L'\t':
-                                       w = min(win->maxx - x,
-                                           TABSIZE - (x % TABSIZE));
-                                       width += w * wcwidth(ws[0]);
-                                       x += w * wcwidth(ws[0]);
+                                       cw = wcwidth(ws[0]);
+                                       if (cw < 0)
+                                               cw = 1;
+                                       w = cw * (TABSIZE - (x % TABSIZE));
+                                       width += w;
+                                       x += w;
                                        len += w;
                                        scp++;
-                                       for (i = 0; i < w; i++ ) {
-                                               *lstr = *ws;
-                                               lstr++;
-                                       }
+                                       *lstr = *ws;
+                                       lstr++;
                                        continue;
                        }
                        w = wcwidth(*scp);