Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

===================================================================
RCS file: /ftp/cvs/cvsroot/src/lib/libcurses/addbytes.c,v
rcsdiff: /ftp/cvs/cvsroot/src/lib/libcurses/addbytes.c,v: warning: Unknown phrases like `commitid ...;' are present.
retrieving revision 1.54
retrieving revision 1.55
diff -u -p -r1.54 -r1.55
--- src/lib/libcurses/addbytes.c	2021/02/13 14:30:37	1.54
+++ src/lib/libcurses/addbytes.c	2021/06/06 05:06:44	1.55
@@ -1,4 +1,4 @@
-/*	$NetBSD: addbytes.c,v 1.54 2021/02/13 14:30:37 rillig Exp $	*/
+/*	$NetBSD: addbytes.c,v 1.55 2021/06/06 05:06:44 blymn Exp $	*/
 
 /*
  * Copyright (c) 1987, 1993, 1994
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)addbytes.c	8.4 (Berkeley) 5/4/94";
 #else
-__RCSID("$NetBSD: addbytes.c,v 1.54 2021/02/13 14:30:37 rillig Exp $");
+__RCSID("$NetBSD: addbytes.c,v 1.55 2021/06/06 05:06:44 blymn Exp $");
 #endif
 #endif				/* not lint */
 
@@ -170,6 +170,15 @@ _cursesi_waddbytes(WINDOW *win, const ch
 		} else if (wc == 0) {
 			break;
 		}
+
+		/* if scrollok is false and we are at the bottom of
+		 * screen and this character would take us past the
+		 * end of the line then we are done.
+		 */
+		if ((win->curx + n >= win->maxx) && 
+		    (!(win->flags & __SCROLLOK)) &&
+		    (win->cury == win->scr_b))
+			break;
 #ifdef DEBUG
 		__CTRACE(__CTRACE_INPUT,
 		    "ADDBYTES WIDE(0x%x [%s], %x) at (%d, %d), ate %d bytes\n",
@@ -214,6 +223,19 @@ _cursesi_addbyte(WINDOW *win, __LINE **l
 		case '\t':
 			tabsize = win->screen->TABSIZE;
 			newx = tabsize - (*x % tabsize);
+			/* if at the bottom of the window and
+			   not allowed to scroll then just do
+			   what we can */
+			if ((*y == win->scr_b) &&
+			    !(win->flags & __SCROLLOK)) {
+				if ((*lp)->flags & __ISPASTEOL) {
+					return OK;
+				}
+
+				if (*x + newx > win->maxx - 1)
+					newx = win->maxx - *x - 1;
+			}
+
 			for (i = 0; i < newx; i++) {
 				if (waddbytes(win, blank, 1) == ERR)
 					return ERR;
@@ -366,6 +388,20 @@ _cursesi_addwchar(WINDOW *win, __LINE **
 			cc.attributes = win->wattr;
 			tabsize = win->screen->TABSIZE;
 			newx = tabsize - (*x % tabsize);
+
+			/* if at the bottom of the window and
+			   not allowed to scroll then just do
+			   what we can */
+			if ((*y == win->scr_b) &&
+			    !(win->flags & __SCROLLOK)) {
+				if ((*lnp)->flags & __ISPASTEOL) {
+					return OK;
+				}
+
+				if (*x + newx > win->maxx - 1)
+					newx = win->maxx - *x - 1;
+			}
+
 			for (i = 0; i < newx; i++) {
 				if (wadd_wch(win, &cc) == ERR)
 					return ERR;