[src/trunk]: src/lib/libcurses curses: Fix werase(3) wide character support

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

details:   https://anonhg.NetBSD.org/src/rev/068b7d4abae7
branches:  trunk
changeset: 745774:068b7d4abae7
user:      roy <roy%NetBSD.org@localhost>
date:      Wed Mar 11 23:47:40 2020 +0000

description:
curses: Fix werase(3) wide character support

We need to consider erasing all attributes, not just WA_ATTRIBUTES.
Fixes PR lib/23910.

While here, make the function a little more readable.

diffstat:

 lib/libcurses/erase.c |  42 +++++++++++++++++++++++-------------------
 1 files changed, 23 insertions(+), 19 deletions(-)

diffs (67 lines):

diff -r 107a11d64e61 -r 068b7d4abae7 lib/libcurses/erase.c
--- a/lib/libcurses/erase.c     Wed Mar 11 21:33:38 2020 +0000
+++ b/lib/libcurses/erase.c     Wed Mar 11 23:47:40 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: erase.c,v 1.28 2019/06/09 07:40:14 blymn Exp $ */
+/*     $NetBSD: erase.c,v 1.29 2020/03/11 23:47:40 roy Exp $   */
 
 /*
  * Copyright (c) 1981, 1993, 1994
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)erase.c    8.2 (Berkeley) 5/4/94";
 #else
-__RCSID("$NetBSD: erase.c,v 1.28 2019/06/09 07:40:14 blymn Exp $");
+__RCSID("$NetBSD: erase.c,v 1.29 2020/03/11 23:47:40 roy Exp $");
 #endif
 #endif                         /* not lint */
 
@@ -79,27 +79,31 @@
        for (y = 0; y < win->maxy; y++) {
                start = win->alines[y]->line;
                end = &start[win->maxx];
-               for (sp = start; sp < end; sp++)
+               for (sp = start; sp < end; sp++) {
 #ifndef HAVE_WCHAR
-                       if (sp->ch != win->bch || sp->attr != 0) {
+                       if (sp->ch == win->bch && sp->attr == 0)
+                               continue;
 #else
-                       if (sp->ch != ( wchar_t )btowc(( int ) win->bch ) ||
-                           (sp->attr & WA_ATTRIBUTES) != 0 || sp->nsp) {
+                       if (sp->ch == (wchar_t)btowc((int)win->bch) &&
+                           sp->attr == 0 &&
+                           sp->nsp == NULL)
+                               continue;
+#endif
+                       if (sp->attr & __ALTCHARSET)
+                               sp->attr = attr | __ALTCHARSET;
+                       else
+                               sp->attr = attr;
+#ifndef HAVE_WCHAR
+                       sp->ch = win->bch;
+#else
+                       sp->ch = (wchar_t)btowc((int)win->bch);
+                       if (_cursesi_copy_nsp(win->bnsp, sp) == ERR)
+                               return ERR;
+                       SET_WCOL(*sp, 1);
 #endif /* HAVE_WCHAR */
-                               if (sp->attr & __ALTCHARSET)
-                                       sp->attr = attr | __ALTCHARSET;
-                               else
-                                       sp->attr = attr;
-#ifdef HAVE_WCHAR
-                               sp->ch = ( wchar_t )btowc(( int ) win->bch);
-                               if (_cursesi_copy_nsp(win->bnsp, sp) == ERR)
-                                       return ERR;
-                               SET_WCOL( *sp, 1 );
-#else
-                               sp->ch = win->bch;
-#endif /* HAVE_WCHAR */
-                       }
+               }
        }
+
        /*
         * Mark the whole window as changed in case we have overlapping
         * windows - this will result in the (intended) clearing of the