Re: CVS commit: src/lib/libcurses

[Ryo ONODERA <ryo%tetera.org@localhost>]

Hi,

The following commit breaks my /usr/bin/vi.
When /usr/bin/vi exits, /usr/bin/vi hangs.
I must kill it with kill(1) command.

I reverted src/lib/libcurses/refresh.c to r1.131 locally
and /usr/bin/vi works fine again.

Could you take a look at my problem?

If you need more information, I can rebuild libcurse with
r1.132 of src/lib/libcurses/refresh.c and collect information.

Thank you.

"Brett Lymn" <blymn%netbsd.org@localhost> writes:

> Module Name:	src
> Committed By:	blymn
> Date:		Mon Jun 29 06:06:10 UTC 2026
>
> Modified Files:
> 	src/lib/libcurses: refresh.c
>
> Log Message:
> Part of fix for PR lib/58282
>
> Redo the logic for erasing lines when we have the capability, it was
> broken and caused blanks to be written when clearing the screen instead
> which caused thrashing and large outputs.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.131 -r1.132 src/lib/libcurses/refresh.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>
> Modified files:
>
> Index: src/lib/libcurses/refresh.c
> diff -u src/lib/libcurses/refresh.c:1.131 src/lib/libcurses/refresh.c:1.132
> --- src/lib/libcurses/refresh.c:1.131	Wed Apr  1 20:32:56 2026
> +++ src/lib/libcurses/refresh.c	Mon Jun 29 06:06:10 2026
> @@ -1,4 +1,4 @@
> -/*	$NetBSD: refresh.c,v 1.131 2026/04/01 20:32:56 hgutch Exp $	*/
> +/*	$NetBSD: refresh.c,v 1.132 2026/06/29 06:06:10 blymn Exp $	*/
>  
>  /*
>   * Copyright (c) 1981, 1993, 1994
> @@ -34,7 +34,7 @@
>  #if 0
>  static char sccsid[] = "@(#)refresh.c	8.7 (Berkeley) 8/13/94";
>  #else
> -__RCSID("$NetBSD: refresh.c,v 1.131 2026/04/01 20:32:56 hgutch Exp $");
> +__RCSID("$NetBSD: refresh.c,v 1.132 2026/06/29 06:06:10 blymn Exp $");
>  #endif
>  #endif				/* not lint */
>  
> @@ -228,6 +228,10 @@ _wnoutrefresh(WINDOW *win, int begy, int
>  	screen->__virtscr->flags &= ~__LEAVEOK;
>  	screen->__virtscr->flags |= dwin->flags;
>  
> +	/* copy the background char and attributes from win to __virtscr */
> +	screen->__virtscr->bch = win->bch;
> +	screen->__virtscr->battr = win->battr;
> +
>  	if ((dwin->flags & __ISDERWIN) != 0)
>  		endy = begy + maxy;
>  	else
> @@ -328,6 +332,7 @@ _wnoutrefresh(WINDOW *win, int begy, int
>  					    CA_CONTINUATION;
>  				}
>  #endif /* HAVE_WCHAR */
> +
>  				if (win->flags & __ISDERWIN) {
>  					dwlp->line[dx_off].ch =
>  						wlp->line[wx].ch;
> @@ -372,6 +377,7 @@ _wnoutrefresh(WINDOW *win, int begy, int
>  					}
>  				}
>  #endif /* HAVE_WCHAR */
> +
>  				__CTRACE(__CTRACE_REFRESH, " = '%s', 0x%x\n",
>  				    unctrl(vlp->line[x_off].ch),
>  				    vlp->line[x_off].attr);
> @@ -402,7 +408,7 @@ _wnoutrefresh(WINDOW *win, int begy, int
>  			    *wlp->firstchp, *wlp->lastchp);
>  			if (win->flags & __ISDERWIN) {
>  				__CTRACE(__CTRACE_REFRESH,
> -				    "derwin: fistch = %d, lastch = %d\n",
> +				    "derwin: firstch = %d, lastch = %d\n",
>  				    *dwlp->firstchp, *dwlp->lastchp);
>  			}
>  #endif
> @@ -436,15 +442,14 @@ _wnoutrefresh(WINDOW *win, int begy, int
>  			}
>  
>  			__CTRACE(__CTRACE_REFRESH,
> -			    "__virtscr: firstch = %d, lastch = %d\n",
> -			    *vlp->firstchp, *vlp->lastchp);
> +			    "__virtscr: firstch = %d, lastch = %d, flags 0x%x\n",
> +			    *vlp->firstchp, *vlp->lastchp, vlp->flags);
>  			/*
> -			 * Unset change pointers only if a window and we
> -			 * are not forcing a redraw. A pad can be displayed
> -			 * again without any of the contents changing.
> +			 * Unset change pointers only if a window 
> +			 * A pad can be displayed again without any
> +			 * of the contents changing.
>  			 */
> -			if (!((win->flags & __ISPAD)) ||
> -			    ((wlp->flags & __ISFORCED) == __ISFORCED))
> +			if (!(win->flags & __ISPAD))
>  			{
>  				/* Set change pointers on "win". */
>  				if (*wlp->firstchp >= win->ch_off)
> @@ -570,9 +575,9 @@ doupdate(void)
>  
>  	if (!_cursesi_screen->curwin) {
>  		for (wy = 0; wy < win->maxy; wy++) {
> -			wlp = win->alines[wy];
> +			wlp = curscr->alines[wy];
>  			if (wlp->flags & __ISDIRTY)
> -				wlp->hash = __hash_line(wlp->line, win->maxx);
> +				wlp->hash = __hash_line(wlp->line, curscr->maxx);
>  		}
>  	}
>  
> @@ -606,15 +611,30 @@ doupdate(void)
>  	    _cursesi_screen->curwin);
>  	__CTRACE(__CTRACE_REFRESH, "doupdate: \tfirstch\tlastch\n");
>  
> +	/* curscr may have been cleared, rehash the dirty lines */
> +	for (wy = 0; wy < win->maxy; wy++) {
> +		wlp = curscr->alines[wy];
> +		if (wlp->flags & __ISDIRTY)
> +			wlp->hash = __hash_line(wlp->line, curscr->maxx);
> +	}
> +
> +	/* and the same with virtscr... */
> +	for (wy = 0; wy < __virtscr->maxy; wy++) {
> +		wlp = __virtscr->alines[wy];
> +		if (wlp->flags & __ISDIRTY)
> +			wlp->hash = __hash_line(wlp->line, __virtscr->maxx);
> +	}
> +
>  	if (!_cursesi_screen->curwin) {
>  		/*
>  		 * Invoke quickch() only if more than a quarter of the lines
> -		 * in the window are dirty.
> +		 * in the window are dirty and we didn't just clear.
>  		 */
>  		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
>  			if (win->alines[wy]->flags & __ISDIRTY)
>  				dnum++;
> -		if (!__noqch && dnum > (int) win->maxy / 4)
> +		if ((!__noqch) && (was_cleared == 0)
> +		    && (dnum > (int) win->maxy / 4))
>  			quickch();
>  	}
>  
> @@ -1145,25 +1165,23 @@ makech(int wy)
>  {
>  	WINDOW	*win;
>  	static __LDATA blank;
> -	__LDATA *nsp, *csp, *cp, *cep, *fsp;
> +	__LDATA *nsp, *csp, *cp, *fsp;
>  	__LINE *wlp;
>  	int	nlsp;	/* offset to first space at eol. */
> -	size_t	mlsp;
>  	int	lch, wx, owx, chw;
>  	const char	*ce;
> -	attr_t	lspc;		/* Last space colour */
>  	attr_t	battr;		/* background attribute bits */
>  	attr_t	attr_mask;	/* attributes mask */
>  
>  #ifdef __GNUC__
> -	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
> +	nlsp = 0;	/* XXX gcc -Wuninitialized */
>  #endif
>  	if (_cursesi_screen->curwin)
>  		win = curscr;
>  	else
>  		win = __virtscr;
>  
> -	blank.ch = win->bch;
> +	blank.ch = (wchar_t) btowc((int) ' ');
>  	blank.attr = win->battr;
>  	blank.cflags = CA_BACKGROUND;
>  #ifdef HAVE_WCHAR
> @@ -1202,6 +1220,8 @@ makech(int wy)
>  
>  	/* Is the cursor still on the end of the last line? */
>  	if (wy > 0 && curscr->alines[wy - 1]->flags & __ISPASTEOL) {
> +		/* XXX this looks wrong - bad things will happen if ly
> +		   is at maxy */
>  		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
>  			_cursesi_screen->ly + 1, 0);
>  		_cursesi_screen->ly++;
> @@ -1221,16 +1241,6 @@ makech(int wy)
>  		if (lch >= (int) win->maxx)
>  			lch = win->maxx - 1;
>  
> -	if (_cursesi_screen->curwin) {
> -		csp = &blank;
> -		__CTRACE(__CTRACE_REFRESH, "makech: csp is blank\n");
> -	} else {
> -		csp = &curscr->alines[wy]->line[wx];
> -		__CTRACE(__CTRACE_REFRESH,
> -		    "makech: csp is on curscr:(%d,%d)\n", wy, wx);
> -	}
> -
> -
>  	while (win->alines[wy]->line[wx].cflags & CA_CONTINUATION) {
>  		wx--;
>  		if (wx <= 0) {
> @@ -1239,6 +1249,15 @@ makech(int wy)
>  		}
>  	}
>  
> +	if (_cursesi_screen->curwin) {
> +		csp = &blank;
> +		__CTRACE(__CTRACE_REFRESH, "makech: csp is blank\n");
> +	} else {
> +		csp = &curscr->alines[wy]->line[wx];
> +		__CTRACE(__CTRACE_REFRESH,
> +		    "makech: csp is on virtscr:(%d,%d)\n", wy, wx);
> +	}
> +
>  	nsp = fsp = &win->alines[wy]->line[wx];
>  
>  #ifdef DEBUG
> @@ -1257,25 +1276,34 @@ makech(int wy)
>  	 */
>  	if (clr_eol && !_cursesi_screen->curwin && (!(__using_color)
>  	    || (__using_color && back_color_erase))) {
> +
> +		if (__using_color && back_color_erase) {
> +			assume_default_colors(
> +			    _cursesi_screen->colour_pairs[PAIR_NUMBER(win->battr)].fore,
> +			    _cursesi_screen->colour_pairs[PAIR_NUMBER(win->battr)].back);
> +		}
> +
>  		nlsp = win->maxx - 1;
>  		cp = &win->alines[wy]->line[win->maxx - 1];
>  #ifdef HAVE_WCHAR
> -		while ((_cursesi_celleq(cp, &blank) == 1) &&
> -#else
> -		while (cp->ch == blank.ch &&
> -#endif /* HAVE_WCHAR */
> -		    ((cp->attr & attr_mask) == battr)) {
> -#ifdef HAVE_WCHAR
> +		while (((_cursesi_celleq(cp, &blank) == 1) &&
> +		    (cp->attr & attr_mask) == battr)) {
>  			nlsp -= cp->wcols;
>  			cp -= cp->wcols;
> +
> +			if (nlsp <= 0)
> +				break;
> +		}
>  #else
> +		while (cp->ch == blank.ch &&
> +		    ((cp->attr & attr_mask) == battr)) {
>  			nlsp--;
>  			cp--;
> -#endif /* HAVE_WCHAR */
>  
>  			if (nlsp <= 0)
>  				break;
>  		}
> +#endif /* HAVE_WCHAR */
>  
>  
>  		if (nlsp < 0)
> @@ -1296,11 +1324,12 @@ makech(int wy)
>  			csp->ch, csp->attr, csp->wcols, win->bch, win->battr,
>  			win->wcols, csp->nsp);
>  #endif
> -		if (!(wlp->flags & __ISFORCED) &&
> -#ifdef HAVE_WCHAR
> -		    ((nsp->cflags & CA_CONTINUATION) != CA_CONTINUATION) &&
> -#endif
> -		    _cursesi_celleq(nsp, csp))
> +
> +		/*
> +		 * If the update is not being forced then skip over
> +		 * all the unchanged characters.
> +		 */
> +		if (!(wlp->flags & __ISFORCED) && _cursesi_celleq(nsp, csp))
>  		{
>  			if (wx <= lch) {
>  				while (wx <= lch && _cursesi_celleq(nsp, csp)) {
> @@ -1324,35 +1353,30 @@ makech(int wy)
>  		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
>  
>  		__CTRACE(__CTRACE_REFRESH, "makech: 1: wx = %d, ly= %d, "
> -		    "lx = %d, newy = %d, newx = %d, lch = %d\n",
> -		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx, lch);
> +		    "lx = %d, newy = %d, newx = %d, lch = %d, nlsp = %d\n",
> +		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx, lch,
> +		    nlsp);
> +
>  		_cursesi_screen->ly = wy;
>  		_cursesi_screen->lx = wx;
>  		owx = wx;
> -		while (wx <= lch &&
> -		       ((wlp->flags & __ISFORCED) || !_cursesi_celleq(nsp, csp)))
> +
> +		if (wx <= lch &&
> +		    ((wlp->flags & __ISFORCED) || !_cursesi_celleq(nsp, csp)))
>  		{
> -			if ((ce != NULL) && (wx >= nlsp) &&
> -			    (nsp->ch == blank.ch) &&
> -			    (__do_color_init == 1 || nsp->attr == blank.attr))
> +			/*
> +			 * Consider clearing the line, if:
> +			 *  - we have a clear to eol capability
> +			 *  - current x pos is past last non blank char
> +			 *  - the win char is blank
> +			 *  - either we are initing colour or the attributes
> +			 *    match.
> +			 *  - Or the character is marked background
> +			 */
> +			if ((clr_eol != NULL) && (wx >= nlsp) &&
> +			    ((nsp->ch == blank.ch) &&
> +			    (__do_color_init == 1 || nsp->attr == blank.attr)))
>  			{
> -				/* Check for clear to end-of-line. */
> -				cep = &win->alines[wy]->line[win->maxx - 1];
> -				while (cep->ch == blank.ch && cep->attr == battr)
> -					if (cep-- <= csp)
> -						break;
> -
> -				mlsp = &win->alines[wy]->line[win->maxx - 1]
> -				    - win->alines[wy]->line
> -				    - win->begx * __LDATASIZE;
> -
> -				__CTRACE(__CTRACE_REFRESH,
> -				    "makech: nlsp = %d, max = %zu, strlen(ce) = %zu\n",
> -				    nlsp, mlsp, strlen(ce));
> -				__CTRACE(__CTRACE_REFRESH,
> -				    "makech: line = %p, cep = %p, begx = %u\n",
> -				    win->alines[wy]->line, cep, win->begx);
> -
>  				/*
>  				 * work out how to clear the line.  If:
>  				 *  - clear len is greater than clear_to_eol len
> @@ -1365,17 +1389,15 @@ makech(int wy)
>  				 * then emit the ce string.
>  				 */
>  				if (((wy == win->maxy - 1) ||
> -				    ((mlsp - wx) > strlen(ce))) &&
> +				    (((win->maxx - 1) - wx) > strlen(ce))) &&
>  				     ((__using_color && back_color_erase) ||
>  				      (! __using_color))) {
>  					if (wlp->line[wx].attr & win->screen->nca) {
>  						__unsetattr(0);
>  					} else if (__using_color &&
> -					    ((__do_color_init == 1) ||
> -					    ((lspc & __COLOR) !=
> -					    (curscr->wattr & __COLOR)))) {
> -						__set_color(curscr, lspc &
> -						    __COLOR);
> +					    (__do_color_init == 1)) {
> +						__set_color(curscr,
> +						    curscr->wattr & __COLOR);
>  					}
>  					tputs(ce, 0, __cputchar);
>  					_cursesi_screen->lx = wx + win->begx;
> @@ -1395,6 +1417,13 @@ makech(int wy)
>  #endif /* HAVE_WCHAR */
>  						assert(csp != &blank);
>  					}
> +
> +					/* We cleared the line, update the
> +					 * the hash
> +					 */
> +					win->alines[wy]->hash = __hash_line(
> +					   win->alines[wy]->line, win->maxx);
> +
>  					return OK;
>  				}
>  			}
> @@ -1408,7 +1437,7 @@ makech(int wy)
>  #endif /* HAVE_WCHAR */
>  			owx = wx;
>  			if (wx + chw >= (win->maxx) &&
> -			    wy == win->maxy - 1 && !_cursesi_screen->curwin)
> +			    wy >= (win->maxy - 1) && !_cursesi_screen->curwin)
>  			{
>  				if (win->flags & __ENDLINE)
>  					__unsetattr(1);
> @@ -1522,8 +1551,6 @@ domvcur(WINDOW *win, int oy, int ox, int
>  	__CTRACE(__CTRACE_REFRESH, "domvcur: (%d,%d)=>(%d,%d) win %p\n",
>  	    oy, ox, ny, nx, win );
>  
> -	__unsetattr(1);
> -
>  	/* Don't move the cursor unless we need to. */
>  	if (oy == ny && ox == nx) {
>  		/* Check EOL. */
> @@ -1531,6 +1558,8 @@ domvcur(WINDOW *win, int oy, int ox, int
>  			return;
>  	}
>  
> +	__unsetattr(1);
> +
>  	/* Clear EOL flags. */
>  	win->alines[oy]->flags &= ~__ISPASTEOL;
>  	win->alines[ny]->flags &= ~__ISPASTEOL;
> @@ -1637,13 +1666,12 @@ quickch(void)
>  	for (bsize = bot - top; bsize >= THRESH; bsize--) {
>  		for (startw = top; startw <= bot - bsize; startw++)
>  			for (starts = top; starts <= bot - bsize; starts++) {
> -/*				for (curw = startw, curs = starts;
> +				for (curw = startw, curs = starts;
>  				    curs < starts + bsize; curw++, curs++)
>  					if (__virtscr->alines[curw]->hash !=
> -					    curscr->alines[curs]->hash)
> -						break;
> -				if (curs != starts + bsize)
> -					continue;*/
> +					    curscr->alines[curs]->hash) {
> +				if (curs == starts + bsize)
> +					goto done;
>  				for (curw = startw, curs = starts;
>  					curs < starts + bsize; curw++, curs++)
>  					if (!lineeq(__virtscr->alines[curw]->line,
> @@ -1651,6 +1679,7 @@ quickch(void)
>  						    (size_t) __virtscr->maxx)) {
>  						found = 1;
>  						break;
> +					}
>  				}
>  				if ((curs == starts + bsize) && (found == 1)) {
>  					goto done;
> @@ -1683,7 +1712,7 @@ done:
>  	__CTRACE(__CTRACE_REFRESH, "quickch: n = %d\n", n);
>  	for (i = 0; i < curscr->maxy; i++) {
>  		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
> -		__CTRACE(__CTRACE_REFRESH, " 0x%x \n", curscr->alines[i]->hash);
> +		__CTRACE(__CTRACE_REFRESH, " hash: 0x%x \n", curscr->alines[i]->hash);
>  		for (j = 0; j < curscr->maxx; j++)
>  			__CTRACE(__CTRACE_REFRESH, "%c",
>  			    curscr->alines[i]->line[j].ch);
> @@ -1694,7 +1723,7 @@ done:
>  			    curscr->alines[i]->line[j].attr);
>  		__CTRACE(__CTRACE_REFRESH, "\n");
>  		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
> -		__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
> +		__CTRACE(__CTRACE_REFRESH, " hash: 0x%x \n",
>  		    __virtscr->alines[i]->hash);
>  		__CTRACE(__CTRACE_REFRESH, " 0x%x ",
>  		    __virtscr->alines[i]->flags);
> @@ -2075,9 +2104,6 @@ __unsetattr(int checkms)
>  		tputs(exit_alt_charset_mode, 0, __cputchar);
>  		curscr->wattr &= ~__ALTCHARSET;
>  	}
> -	/* Don't leave the screen with colour set (check against ms). */
> -	if (__using_color && isms)
> -		__unset_color(curscr);
>  }
>  
>  /* compare two line segments */
>

-- 
Ryo ONODERA // ryo%tetera.org@localhost
PGP fingerprint = 82A2 DC91 76E0 A10A 8ABB  FD1B F404 27FA C7D1 15F3