xref: /netbsd-src/lib/libcurses/refresh.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: refresh.c,v 1.117 2021/12/17 03:50:18 uwe Exp $	*/
2 
3 /*
4  * Copyright (c) 1981, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)refresh.c	8.7 (Berkeley) 8/13/94";
36 #else
37 __RCSID("$NetBSD: refresh.c,v 1.117 2021/12/17 03:50:18 uwe Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #include <poll.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <assert.h>
45 
46 #include "curses.h"
47 #include "curses_private.h"
48 
49 static void	domvcur(WINDOW *, int, int, int, int);
50 static void	putattr(__LDATA *);
51 static void	putattr_out(__LDATA *);
52 static int	putch(__LDATA *, __LDATA *, int, int);
53 static int	putchbr(__LDATA *, __LDATA *, __LDATA *, int, int);
54 static int	makech(int);
55 static void	quickch(void);
56 static void	scrolln(int, int, int, int, int);
57 
58 static int	_wnoutrefresh(WINDOW *, int, int, int, int, int, int);
59 
60 #ifdef HAVE_WCHAR
61 static int celleq(__LDATA *, __LDATA *);
62 static int lineeq(__LDATA *, __LDATA *, size_t);
63 #else  /* !HAVE_WCHAR */
64 static inline int
65 celleq(__LDATA *x, __LDATA *y)
66 {
67 	return memcmp(x, y, sizeof(__LDATA)) == 0;
68 }
69 
70 static int
71 lineeq(__LDATA *xl, __LDATA *yl, size_t len)
72 {
73 	return memcmp(xl, yl, len * __LDATASIZE) == 0;
74 }
75 #endif /* HAVE_WCHAR */
76 
77 #define	CHECK_INTERVAL		5 /* Change N lines before checking typeahead */
78 
79 #ifndef _CURSES_USE_MACROS
80 
81 /*
82  * refresh --
83  *	Make the current screen look like "stdscr" over the area covered by
84  *	stdscr.
85  */
86 int
87 refresh(void)
88 {
89 
90 	return wrefresh(stdscr);
91 }
92 
93 #endif
94 
95 /*
96  * wnoutrefresh --
97  *	Add the contents of "win" to the virtual window.
98  */
99 int
100 wnoutrefresh(WINDOW *win)
101 {
102 
103 	__CTRACE(__CTRACE_REFRESH,
104 	    "wnoutrefresh: win %p, begy %d, begx %d, maxy %d, maxx %d\n",
105 	    win, win->begy, win->begx, win->maxy, win->maxx);
106 
107 	return _wnoutrefresh(win, 0, 0, win->begy, win->begx,
108 	    win->maxy, win->maxx);
109 }
110 
111 /*
112  * pnoutrefresh --
113  *	Add the contents of "pad" to the virtual window.
114  */
115 int
116 pnoutrefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
117 	     int smaxy, int smaxx)
118 {
119 	int pmaxy, pmaxx;
120 
121 	__CTRACE(__CTRACE_REFRESH, "pnoutrefresh: pad %p, flags 0x%08x\n",
122 	    pad, pad->flags);
123 	__CTRACE(__CTRACE_REFRESH,
124 	    "pnoutrefresh: (%d, %d), (%d, %d), (%d, %d)\n",
125 	    pbegy, pbegx, sbegy, sbegx, smaxy, smaxx);
126 
127 	/* SUS says if these are negative, they should be treated as zero */
128 	if (pbegy < 0)
129 		pbegy = 0;
130 	if (pbegx < 0)
131 		pbegx = 0;
132 	if (sbegy < 0)
133 		sbegy = 0;
134 	if (sbegx < 0)
135 		sbegx = 0;
136 
137 	/* Calculate rectangle on pad - used by _wnoutrefresh */
138 	pmaxy = pbegy + smaxy - sbegy + 1;
139 	pmaxx = pbegx + smaxx - sbegx + 1;
140 
141 	/* Check rectangle fits in pad */
142 	if (pmaxy > pad->maxy - pad->begy)
143 		pmaxy = pad->maxy - pad->begy;
144 	if (pmaxx > pad->maxx - pad->begx)
145 		pmaxx = pad->maxx - pad->begx;
146 
147 	if (smaxy - sbegy < 0 || smaxx - sbegx < 0 )
148 		return ERR;
149 
150 	return _wnoutrefresh(pad,
151 	    pad->begy + pbegy, pad->begx + pbegx, pad->begy + sbegy,
152 	    pad->begx + sbegx, pmaxy, pmaxx);
153 }
154 
155 /*
156  * _wnoutrefresh --
157  *	Does the grunt work for wnoutrefresh to the given screen.
158  *	Copies the part of the window given by the rectangle
159  *	(begy, begx) to (maxy, maxx) at screen position (wbegy, wbegx).
160  */
161 static int
162 _wnoutrefresh(WINDOW *win, int begy, int begx, int wbegy, int wbegx,
163               int maxy, int maxx)
164 {
165 	SCREEN *screen = win->screen;
166 	short	sy, wy, wx, y_off, x_off, mx, dy_off, dx_off, endy;
167 	int newy, newx;
168 	__LINE	*wlp, *vlp, *dwlp;
169 	WINDOW	*sub_win, *orig, *swin, *dwin;
170 
171 	__CTRACE(__CTRACE_REFRESH, "_wnoutrefresh: win %p, flags 0x%08x\n",
172 	    win, win->flags);
173 	__CTRACE(__CTRACE_REFRESH,
174 	    "_wnoutrefresh: (%d, %d), (%d, %d), (%d, %d)\n",
175 	    begy, begx, wbegy, wbegx, maxy, maxx);
176 
177 	if (screen->curwin)
178 		return OK;
179 
180 	swin = dwin = win;
181 	if (win->flags & __ISDERWIN)
182 		swin = win->orig;
183 
184 	/*
185 	 * Recurse through any sub-windows, mark as dirty lines on the parent
186 	 * window that are dirty on the sub-window and clear the dirty flag on
187 	 * the sub-window.
188 	 */
189 	if (dwin->orig == 0) {
190 		orig = dwin;
191 		for (sub_win = dwin->nextp; sub_win != orig;
192 		    sub_win = sub_win->nextp) {
193 			if (sub_win->flags & __ISDERWIN)
194 				continue;
195 			__CTRACE(__CTRACE_REFRESH,
196 			    "wnout_refresh: win %p, sub_win %p\n",
197 			    orig, sub_win);
198 			for (sy = 0; sy < sub_win->maxy; sy++) {
199 				if (sub_win->alines[sy]->flags & __ISDIRTY) {
200 					orig->alines[sy + sub_win->begy - orig->begy]->flags
201 					    |= __ISDIRTY;
202 					sub_win->alines[sy]->flags
203 					    &= ~__ISDIRTY;
204 				}
205 				if (sub_win->alines[sy]->flags & __ISFORCED) {
206 					orig->alines[sy + sub_win->begy - orig->begy]->flags
207 					    |= __ISFORCED;
208 					sub_win->alines[sy]->flags
209 					    &= ~__ISFORCED;
210 				}
211 			}
212 		}
213 	}
214 
215 	/* Check that cursor position on "win" is valid for "__virtscr" */
216 	newy = wbegy + dwin->cury - begy;
217 	newx = wbegx + dwin->curx - begx;
218 	if (begy <= dwin->cury && dwin->cury < maxy
219 	    && 0 <= newy && newy < screen->__virtscr->maxy)
220 		screen->__virtscr->cury = newy;
221 	if (begx <= dwin->curx && dwin->curx < maxx
222 	    && 0 <= newx && newx < screen->__virtscr->maxx)
223 		screen->__virtscr->curx = newx;
224 
225 	/* Copy the window flags from "win" to "__virtscr" */
226 	if (dwin->flags & __CLEAROK) {
227 		if (dwin->flags & __FULLWIN)
228 			screen->__virtscr->flags |= __CLEAROK;
229 		dwin->flags &= ~__CLEAROK;
230 	}
231 	screen->__virtscr->flags &= ~__LEAVEOK;
232 	screen->__virtscr->flags |= dwin->flags;
233 
234 	if ((dwin->flags & __ISDERWIN) != 0)
235 		endy = begy + maxy;
236 	else
237 		endy = maxy;
238 
239 	for (wy = begy, y_off = wbegy, dy_off = 0; wy < endy &&
240 	    y_off < screen->__virtscr->maxy; wy++, y_off++, dy_off++)
241 	{
242 		wlp = swin->alines[wy];
243 		dwlp = dwin->alines[dy_off];
244 #ifdef DEBUG
245 		__CTRACE(__CTRACE_REFRESH,
246 		    "_wnoutrefresh: wy %d\tf %d\tl %d\tflags %x\n",
247 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
248 
249 		char *_wintype;
250 
251 		if ((dwin->flags & __ISDERWIN) != 0)
252 			_wintype = "derwin";
253 		else
254 			_wintype = "dwin";
255 
256 		__CTRACE(__CTRACE_REFRESH,
257 		    "_wnoutrefresh: %s wy %d\tf %d\tl %d\tflags %x\n",
258 		    _wintype, dy_off, *dwlp->firstchp, *dwlp->lastchp,
259 		    dwlp->flags);
260 		__CTRACE(__CTRACE_REFRESH,
261 		    "_wnoutrefresh: %s maxx %d\tch_off %d wlp %p\n",
262 		    _wintype, dwin->maxx, dwin->ch_off, wlp);
263 #endif
264 		if (((wlp->flags & (__ISDIRTY | __ISFORCED)) == 0) &&
265 		    ((dwlp->flags & (__ISDIRTY | __ISFORCED)) == 0))
266 			continue;
267 		__CTRACE(__CTRACE_REFRESH,
268 		    "_wnoutrefresh: line y_off %d (dy_off %d) is dirty\n",
269 		    y_off, dy_off);
270 
271 		wlp = swin->alines[wy];
272 		vlp = screen->__virtscr->alines[y_off];
273 
274 		if ((*wlp->firstchp < maxx + swin->ch_off &&
275 		    *wlp->lastchp >= swin->ch_off) ||
276 		    ((((dwin->flags & __ISDERWIN) != 0) &&
277 		     (*dwlp->firstchp < dwin->maxx + dwin->ch_off &&
278 		      *dwlp->lastchp >= dwin->ch_off))))
279 		{
280 			/* Set start column */
281 			wx = begx;
282 			x_off = wbegx;
283 			dx_off = 0;
284 			/*
285 			 * if a derwin then source change pointers aren't
286 			 * relevant.
287 			 */
288 			if ((dwin->flags & __ISDERWIN) != 0)
289 				mx = wx + maxx;
290 			else {
291 				if (*wlp->firstchp - swin->ch_off > 0) {
292 					wx += *wlp->firstchp - swin->ch_off;
293 					x_off += *wlp->firstchp - swin->ch_off;
294 				}
295 				mx = maxx;
296 				if (mx > *wlp->lastchp - swin->ch_off + 1)
297 					mx = *dwlp->lastchp - dwin->ch_off + 1;
298 				if (x_off + (mx - wx) > screen->__virtscr->maxx)
299 					mx -= (x_off + maxx) -
300 					    screen->__virtscr->maxx;
301 			}
302 
303 			/* Copy line from "win" to "__virtscr". */
304 			while (wx < mx) {
305 				__CTRACE(__CTRACE_REFRESH,
306 				    "_wnoutrefresh: copy from %d, "
307 				    "%d to %d, %d: %s, 0x%x",
308 				    wy, wx, y_off, x_off,
309 				    unctrl(wlp->line[wx].ch),
310 				    wlp->line[wx].attr);
311 				__CTRACE(__CTRACE_REFRESH,
312 				    " (curdest %s, 0x%x)",
313 				    unctrl(vlp->line[x_off].ch),
314 				    vlp->line[x_off].attr);
315 				/* Copy character */
316 				vlp->line[x_off].ch = wlp->line[wx].ch;
317 				/* Copy attributes  */
318 				vlp->line[x_off].attr = wlp->line[wx].attr;
319 				/* Check for nca conflict with colour */
320 				if ((vlp->line[x_off].attr & __COLOR) &&
321 				    (vlp->line[x_off].attr & screen->nca))
322 					vlp->line[x_off].attr &= ~__COLOR;
323 				if (win->flags & __ISDERWIN) {
324 					dwlp->line[dx_off].ch =
325 						wlp->line[wx].ch;
326 					dwlp->line[dx_off].attr =
327 						wlp->line[wx].attr;
328 				}
329 
330 #ifdef HAVE_WCHAR
331 				if (wlp->line[wx].ch
332 				    == (wchar_t)btowc((int) win->bch)) {
333 					vlp->line[x_off].ch = win->bch;
334 					SET_WCOL(vlp->line[x_off], 1);
335 					if (_cursesi_copy_nsp(win->bnsp,
336 							      &vlp->line[x_off])
337 					    == ERR)
338 						return ERR;
339 					if (win->flags & __ISDERWIN) {
340 						dwlp->line[dx_off].ch =
341 							win->bch;
342 						SET_WCOL(dwlp->line[dx_off], 1);
343 						if (_cursesi_copy_nsp(win->bnsp,
344 						     &dwlp->line[dx_off])
345 						    == ERR)
346 							return ERR;
347 					}
348 				}
349 #endif /* HAVE_WCHAR */
350 				__CTRACE(__CTRACE_REFRESH, " = %s, 0x%x\n",
351 				    unctrl(vlp->line[x_off].ch),
352 				    vlp->line[x_off].attr);
353 				wx++;
354 				x_off++;
355 				dx_off++;
356 			}
357 
358 			/* Set flags on "__virtscr" and unset on "win". */
359 			if (wlp->flags & __ISPASTEOL)
360 				vlp->flags |= __ISPASTEOL;
361 			else
362 				vlp->flags &= ~__ISPASTEOL;
363 			if (wlp->flags & __ISDIRTY)
364 				vlp->flags |= __ISDIRTY;
365 			if (wlp->flags & __ISFORCED)
366 				vlp->flags |= __ISFORCED;
367 
368 #ifdef DEBUG
369 			__CTRACE(__CTRACE_REFRESH,
370 			    "win: firstch = %d, lastch = %d\n",
371 			    *wlp->firstchp, *wlp->lastchp);
372 			if (win->flags & __ISDERWIN) {
373 				__CTRACE(__CTRACE_REFRESH,
374 				    "derwin: fistch = %d, lastch = %d\n",
375 				    *dwlp->firstchp, *dwlp->lastchp);
376 			}
377 #endif
378 			/* Set change pointers on "__virtscr". */
379 			if (*vlp->firstchp >
380 				*wlp->firstchp + wbegx - win->ch_off)
381 					*vlp->firstchp =
382 					    *wlp->firstchp + wbegx - win->ch_off;
383 			if (*vlp->lastchp <
384 				*wlp->lastchp + wbegx - win->ch_off)
385 					*vlp->lastchp =
386 					    *wlp->lastchp + wbegx - win->ch_off;
387 
388 			if (win->flags & __ISDERWIN) {
389 				if (*vlp->firstchp >
390 				    *dwlp->firstchp + wbegx - dwin->ch_off)
391 				{
392 					*vlp->firstchp =
393 					    *dwlp->firstchp + wbegx
394 						- dwin->ch_off;
395 					vlp->flags |= __ISDIRTY;
396 				}
397 
398 				if (*vlp->lastchp <
399 				    *dwlp->lastchp + wbegx - dwin->ch_off)
400 				{
401 					*vlp->lastchp = *dwlp->lastchp
402 					    + wbegx - dwin->ch_off;
403 					vlp->flags |= __ISDIRTY;
404 				}
405 			}
406 
407 			__CTRACE(__CTRACE_REFRESH,
408 			    "__virtscr: firstch = %d, lastch = %d\n",
409 			    *vlp->firstchp, *vlp->lastchp);
410 			/*
411 			 * Unset change pointers only if a window and we
412 			 * are not forcing a redraw. A pad can be displayed
413 			 * again without any of the contents changing.
414 			 */
415 			if ((!(win->flags & __ISPAD)) ||
416 			    ((wlp->flags & __ISFORCED) == __ISFORCED))
417 			{
418 				/* Set change pointers on "win". */
419 				if (*wlp->firstchp >= win->ch_off)
420 					*wlp->firstchp = maxx + win->ch_off;
421 				if (*wlp->lastchp < maxx + win->ch_off)
422 					*wlp->lastchp = win->ch_off;
423 				if ((*wlp->lastchp < *wlp->firstchp) ||
424 				    (*wlp->firstchp >= maxx + win->ch_off) ||
425 				    (*wlp->lastchp <= win->ch_off)) {
426 					__CTRACE(__CTRACE_REFRESH,
427 					    "_wnoutrefresh: "
428 					    "line %d notdirty\n", wy);
429 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
430 				}
431 			}
432 		}
433 	}
434 	return OK;
435 }
436 
437 /*
438  * wrefresh --
439  *	Make the current screen look like "win" over the area covered by
440  *	win.
441  */
442 int
443 wrefresh(WINDOW *win)
444 {
445 	int retval;
446 	int pbegx, pbegy;
447 
448 	__CTRACE(__CTRACE_REFRESH, "wrefresh: win %p\n", win);
449 
450 	_cursesi_screen->curwin = (win == _cursesi_screen->curscr);
451 	if (!_cursesi_screen->curwin) {
452 		pbegx = pbegy = 0;
453 		if ((win->flags & __ISDERWIN) == __ISDERWIN) {
454 			pbegx = win->derx;
455 			pbegy = win->dery;
456 	__CTRACE(__CTRACE_REFRESH, "wrefresh: derwin, begy = %d, begx = %x\n",
457 		pbegy, pbegx);
458 		}
459 		retval = _wnoutrefresh(win, pbegy, pbegx, win->begy, win->begx,
460 		    win->maxy, win->maxx);
461 	} else
462 		retval = OK;
463 	if (retval == OK) {
464 		retval = doupdate();
465 		if (!(win->flags & __LEAVEOK)) {
466 			win->cury = max(0, curscr->cury - win->begy);
467 			win->curx = max(0, curscr->curx - win->begx);
468 		}
469 	}
470 	_cursesi_screen->curwin = 0;
471 	return retval;
472 }
473 
474  /*
475  * prefresh --
476  *	Make the current screen look like "pad" over the area coverd by
477  *	the specified area of pad.
478  */
479 int
480 prefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
481 	int smaxy, int smaxx)
482 {
483 	int retval;
484 
485 	__CTRACE(__CTRACE_REFRESH, "prefresh: pad %p, flags 0x%08x\n",
486 	    pad, pad->flags);
487 	/* Retain values in case pechochar() is called. */
488 	pad->pbegy = pbegy;
489 	pad->pbegx = pbegx;
490 	pad->sbegy = sbegy;
491 	pad->sbegx = sbegx;
492 	pad->smaxy = smaxy;
493 	pad->smaxx = smaxx;
494 
495 	/* Use pnoutrefresh() to avoid duplicating code here */
496 	retval = pnoutrefresh(pad, pbegy, pbegx, sbegy, sbegx, smaxy, smaxx);
497 	if (retval == OK) {
498 		retval = doupdate();
499 		if (!(pad->flags & __LEAVEOK)) {
500 			pad->cury = max(0, pbegy + (curscr->cury - sbegy));
501 			pad->curx = max(0, pbegx + (curscr->curx - sbegx));
502 		}
503 	}
504 	return retval;
505 }
506 
507 /*
508  * doupdate --
509  *	Make the current screen look like the virtual window "__virtscr".
510  */
511 int
512 doupdate(void)
513 {
514 	WINDOW	*win;
515 	__LINE	*wlp, *vlp;
516 	short	 wy;
517 	int	 dnum, was_cleared, changed;
518 
519 	/* Check if we need to restart ... */
520 	if (_cursesi_screen->endwin)
521 		__restartwin();
522 
523 	if (_cursesi_screen->curwin)
524 		win = curscr;
525 	else
526 		win = _cursesi_screen->__virtscr;
527 
528 	/* Initialize loop parameters. */
529 	_cursesi_screen->ly = curscr->cury;
530 	_cursesi_screen->lx = curscr->curx;
531 	wy = 0;
532 
533 	if (!_cursesi_screen->curwin) {
534 		for (wy = 0; wy < win->maxy; wy++) {
535 			wlp = win->alines[wy];
536 			if (wlp->flags & __ISDIRTY)
537 				wlp->hash = __hash_line(wlp->line, win->maxx);
538 		}
539 	}
540 
541 	was_cleared = 0;
542 	if ((win->flags & __CLEAROK) || (curscr->flags & __CLEAROK) ||
543 	    _cursesi_screen->curwin)
544 	{
545 		if (curscr->wattr & __COLOR)
546 			__unsetattr(0);
547 		tputs(clear_screen, 0, __cputchar);
548 		_cursesi_screen->ly = 0;
549 		_cursesi_screen->lx = 0;
550 		if (!_cursesi_screen->curwin) {
551 			curscr->flags &= ~__CLEAROK;
552 			curscr->cury = 0;
553 			curscr->curx = 0;
554 			werase(curscr);
555 		}
556 		__touchwin(win);
557 		win->flags &= ~__CLEAROK;
558 		/* note we cleared for later */
559 		was_cleared = 1;
560 	}
561 	if (!cursor_address) {
562 		if (win->curx != 0)
563 			__cputchar('\n');
564 		if (!_cursesi_screen->curwin)
565 			werase(curscr);
566 	}
567 	__CTRACE(__CTRACE_REFRESH, "doupdate: (%p): curwin = %d\n", win,
568 	    _cursesi_screen->curwin);
569 	__CTRACE(__CTRACE_REFRESH, "doupdate: \tfirstch\tlastch\n");
570 
571 	if (!_cursesi_screen->curwin) {
572 		/*
573 		 * Invoke quickch() only if more than a quarter of the lines
574 		 * in the window are dirty.
575 		 */
576 		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
577 			if (win->alines[wy]->flags & __ISDIRTY)
578 				dnum++;
579 		if (!__noqch && dnum > (int) win->maxy / 4)
580 			quickch();
581 	}
582 
583 #ifdef DEBUG
584 	{
585 		int	i, j;
586 
587 		__CTRACE(__CTRACE_REFRESH,
588 		    "#####################################\n");
589 		__CTRACE(__CTRACE_REFRESH,
590 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
591 		    stdscr, curscr, _cursesi_screen->__virtscr);
592 		for (i = 0; i < curscr->maxy; i++) {
593 			__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
594 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
595 			    curscr->alines[i]->hash);
596 			for (j = 0; j < curscr->maxx; j++)
597 				__CTRACE(__CTRACE_REFRESH, "%c",
598 				    curscr->alines[i]->line[j].ch);
599 			__CTRACE(__CTRACE_REFRESH, "\n");
600 			__CTRACE(__CTRACE_REFRESH, " attr:");
601 			for (j = 0; j < curscr->maxx; j++)
602 				__CTRACE(__CTRACE_REFRESH, " %x",
603 				    curscr->alines[i]->line[j].attr);
604 			__CTRACE(__CTRACE_REFRESH, "\n");
605 			__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
606 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
607 			    win->alines[i]->hash);
608 			__CTRACE(__CTRACE_REFRESH, " 0x%x ",
609 			    win->alines[i]->flags);
610 			for (j = 0; j < win->maxx; j++)
611 				__CTRACE(__CTRACE_REFRESH, "%c",
612 				    win->alines[i]->line[j].ch);
613 			__CTRACE(__CTRACE_REFRESH, "\n");
614 			__CTRACE(__CTRACE_REFRESH, " attr:");
615 			for (j = 0; j < win->maxx; j++)
616 				__CTRACE(__CTRACE_REFRESH, " %x",
617 				    win->alines[i]->line[j].attr);
618 			__CTRACE(__CTRACE_REFRESH, "\n");
619 #ifdef HAVE_WCHAR
620 			__CTRACE(__CTRACE_REFRESH, " nsp:");
621 			for (j = 0; j < curscr->maxx; j++)
622 				__CTRACE(__CTRACE_REFRESH, " %p",
623 				    win->alines[i]->line[j].nsp);
624 			__CTRACE(__CTRACE_REFRESH, "\n");
625 			__CTRACE(__CTRACE_REFRESH, " bnsp:");
626 			for (j = 0; j < curscr->maxx; j++)
627 				__CTRACE(__CTRACE_REFRESH, " %p",
628 				    win->bnsp);
629 			__CTRACE(__CTRACE_REFRESH, "\n");
630 #endif /* HAVE_WCHAR */
631 		}
632 	}
633 #endif /* DEBUG */
634 
635 	changed = 0;
636 	for (wy = 0; wy < win->maxy; wy++) {
637 		wlp = win->alines[wy];
638 		vlp = _cursesi_screen->__virtscr->alines[win->begy + wy];
639 /* XXX: remove this */
640 		__CTRACE(__CTRACE_REFRESH,
641 		    "doupdate: wy %d\tf: %d\tl:%d\tflags %x\n",
642 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
643 		if (!_cursesi_screen->curwin)
644 			curscr->alines[wy]->hash = wlp->hash;
645 		if (wlp->flags & __ISDIRTY || wlp->flags & __ISFORCED) {
646 			__CTRACE(__CTRACE_REFRESH,
647 			    "doupdate: [ISDIRTY]wy:%d\tf:%d\tl:%d\n", wy,
648 			    *wlp->firstchp, *wlp->lastchp);
649 			/*
650 			 * We have just cleared so don't force an update
651 			 * otherwise we spray neeedless blanks to a cleared
652 			 * screen.
653 			 */
654 			if (was_cleared == 1)
655 				win->alines[wy]->flags &= ~__ISFORCED;
656 
657 			if (makech(wy) == ERR)
658 				return ERR;
659 			else {
660 				if (*wlp->firstchp >= 0)
661 					*wlp->firstchp = win->maxx;
662 				if (*wlp->lastchp < win->maxx)
663 					*wlp->lastchp = win->ch_off;
664 				if (*wlp->lastchp < *wlp->firstchp) {
665 					__CTRACE(__CTRACE_REFRESH,
666 					    "doupdate: line %d notdirty\n", wy);
667 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
668 				}
669 
670 				/* Check if we have input after
671 				 * changing N lines. */
672 				if (_cursesi_screen->checkfd != -1 &&
673 				    ++changed == CHECK_INTERVAL)
674 				{
675 					struct pollfd fds[1];
676 
677 					/* If we have input, abort. */
678 					fds[0].fd = _cursesi_screen->checkfd;
679 					fds[0].events = POLLIN;
680 					if (poll(fds, 1, 0) > 0)
681 						goto cleanup;
682 					changed = 0;
683 				}
684 			}
685 		}
686 
687 		/*
688 		 * virtscr is now synced for the line, unset the change
689 		 * pointers.
690 		 */
691 		if (*vlp->firstchp >= 0)
692 			*vlp->firstchp = _cursesi_screen->__virtscr->maxx;
693 		if (*vlp->lastchp <= _cursesi_screen->__virtscr->maxx)
694 			*vlp->lastchp = 0;
695 
696 		__CTRACE(__CTRACE_REFRESH, "\t%d\t%d\n",
697 		    *wlp->firstchp, *wlp->lastchp);
698 	}
699 
700 	__CTRACE(__CTRACE_REFRESH, "doupdate: ly=%d, lx=%d\n",
701 	    _cursesi_screen->ly, _cursesi_screen->lx);
702 
703 	if (_cursesi_screen->curwin)
704 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
705 			win->cury, win->curx);
706 	else {
707 		if (win->flags & __LEAVEOK) {
708 			curscr->cury = _cursesi_screen->ly;
709 			curscr->curx = _cursesi_screen->lx;
710 		} else {
711 			domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
712 				win->cury, win->curx);
713 			curscr->cury = win->cury;
714 			curscr->curx = win->curx;
715 		}
716 	}
717 
718 cleanup:
719 	/* Don't leave the screen with attributes set. */
720 	__unsetattr(0);
721 #ifdef DEBUG
722 #ifdef HAVE_WCHAR
723 	{
724 		int	i, j;
725 
726 		__CTRACE(__CTRACE_REFRESH,
727 		    "***********after*****************\n");
728 		__CTRACE(__CTRACE_REFRESH,
729 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
730 		    stdscr, curscr, _cursesi_screen->__virtscr);
731 		for (i = 0; i < curscr->maxy; i++) {
732 			for (j = 0; j < curscr->maxx; j++)
733 				__CTRACE(__CTRACE_REFRESH,
734 				    "[%d,%d](%x,%x,%p)-(%x,%x,%p)\n",
735 				    i, j,
736 				    curscr->alines[i]->line[j].ch,
737 				    curscr->alines[i]->line[j].attr,
738 				    curscr->alines[i]->line[j].nsp,
739 				    _cursesi_screen->__virtscr->alines[i]->line[j].ch,
740 				    _cursesi_screen->__virtscr->alines[i]->line[j].attr,
741 				    _cursesi_screen->__virtscr->alines[i]->line[j].nsp);
742 		}
743 	}
744 #endif /* HAVE_WCHAR */
745 #endif /* DEBUG */
746 	return fflush(_cursesi_screen->outfd) == EOF ? ERR : OK;
747 }
748 
749 static void
750 putattr(__LDATA *nsp)
751 {
752 	attr_t	off, on;
753 
754 	__CTRACE(__CTRACE_REFRESH,
755 	    "makech: have attr %08x, need attr %08x\n",
756 	    curscr->wattr
757 #ifndef HAVE_WCHAR
758 	    & __ATTRIBUTES
759 #else
760 	    & WA_ATTRIBUTES
761 #endif
762 	    ,  nsp->attr
763 #ifndef HAVE_WCHAR
764 	    & __ATTRIBUTES
765 #else
766 	    & WA_ATTRIBUTES
767 #endif
768 	    );
769 
770 	off = (~nsp->attr & curscr->wattr)
771 #ifndef HAVE_WCHAR
772 	    & __ATTRIBUTES
773 #else
774 	    & WA_ATTRIBUTES
775 #endif
776 	    ;
777 
778 	/*
779 	 * Unset attributes as appropriate.  Unset first
780 	 * so that the relevant attributes can be reset
781 	 * (because 'me' unsets 'mb', 'md', 'mh', 'mk',
782 	 * 'mp' and 'mr').  Check to see if we also turn off
783 	 * standout, attributes and colour.
784 	 */
785 	if (off & __TERMATTR && exit_attribute_mode != NULL) {
786 		tputs(exit_attribute_mode, 0, __cputchar);
787 		curscr->wattr &= __mask_me;
788 		off &= __mask_me;
789 	}
790 
791 	/*
792 	 * Exit underscore mode if appropriate.
793 	 * Check to see if we also turn off standout,
794 	 * attributes and colour.
795 	 */
796 	if (off & __UNDERSCORE && exit_underline_mode != NULL) {
797 		tputs(exit_underline_mode, 0, __cputchar);
798 		curscr->wattr &= __mask_ue;
799 		off &= __mask_ue;
800 	}
801 
802 	/*
803 	 * Exit standout mode as appropriate.
804 	 * Check to see if we also turn off underscore,
805 	 * attributes and colour.
806 	 * XXX
807 	 * Should use uc if so/se not available.
808 	 */
809 	if (off & __STANDOUT && exit_standout_mode != NULL) {
810 		tputs(exit_standout_mode, 0, __cputchar);
811 		curscr->wattr &= __mask_se;
812 		off &= __mask_se;
813 	}
814 
815 	if (off & __ALTCHARSET && exit_alt_charset_mode != NULL) {
816 		tputs(exit_alt_charset_mode, 0, __cputchar);
817 		curscr->wattr &= ~__ALTCHARSET;
818 	}
819 
820 	/* Set/change colour as appropriate. */
821 	if (__using_color)
822 		__set_color(curscr, nsp->attr & __COLOR);
823 
824 	on = (nsp->attr & ~curscr->wattr)
825 #ifndef HAVE_WCHAR
826 	    & __ATTRIBUTES
827 #else
828 	    & WA_ATTRIBUTES
829 #endif
830 	    ;
831 
832 	/*
833 	 * Enter standout mode if appropriate.
834 	 */
835 	if (on & __STANDOUT &&
836 	    enter_standout_mode != NULL &&
837 	    exit_standout_mode != NULL)
838 	{
839 		tputs(enter_standout_mode, 0, __cputchar);
840 		curscr->wattr |= __STANDOUT;
841 	}
842 
843 	/*
844 	 * Enter underscore mode if appropriate.
845 	 * XXX
846 	 * Should use uc if us/ue not available.
847 	 */
848 	if (on & __UNDERSCORE &&
849 	    enter_underline_mode != NULL &&
850 	    exit_underline_mode != NULL)
851 	{
852 		tputs(enter_underline_mode, 0, __cputchar);
853 		curscr->wattr |= __UNDERSCORE;
854 	}
855 
856 	/*
857 	 * Set other attributes as appropriate.
858 	 */
859 	if (exit_attribute_mode != NULL) {
860 		if (on & __BLINK && enter_blink_mode != NULL)
861 		{
862 			tputs(enter_blink_mode, 0, __cputchar);
863 			curscr->wattr |= __BLINK;
864 		}
865 		if (on & __BOLD && enter_bold_mode != NULL)
866 		{
867 			tputs(enter_bold_mode, 0, __cputchar);
868 			curscr->wattr |= __BOLD;
869 		}
870 		if (on & __DIM && enter_dim_mode != NULL)
871 		{
872 			tputs(enter_dim_mode, 0, __cputchar);
873 			curscr->wattr |= __DIM;
874 		}
875 		if (on & __BLANK && enter_secure_mode != NULL)
876 		{
877 			tputs(enter_secure_mode, 0, __cputchar);
878 			curscr->wattr |= __BLANK;
879 		}
880 		if (on & __PROTECT && enter_protected_mode != NULL)
881 		{
882 			tputs(enter_protected_mode, 0, __cputchar);
883 			curscr->wattr |= __PROTECT;
884 		}
885 		if (on & __REVERSE && enter_reverse_mode != NULL)
886 		{
887 			tputs(enter_reverse_mode, 0, __cputchar);
888 			curscr->wattr |= __REVERSE;
889 		}
890 #ifdef HAVE_WCHAR
891 		if (on & WA_TOP && enter_top_hl_mode != NULL)
892 		{
893 			tputs(enter_top_hl_mode, 0, __cputchar);
894 			curscr->wattr |= WA_TOP;
895 		}
896 		if (on & WA_LOW && enter_low_hl_mode != NULL)
897 		{
898 			tputs(enter_low_hl_mode, 0, __cputchar);
899 			curscr->wattr |= WA_LOW;
900 		}
901 		if (on & WA_LEFT && enter_left_hl_mode != NULL)
902 		{
903 			tputs(enter_left_hl_mode, 0, __cputchar);
904 			curscr->wattr |= WA_LEFT;
905 		}
906 		if (on & WA_RIGHT && enter_right_hl_mode != NULL)
907 		{
908 			tputs(enter_right_hl_mode, 0, __cputchar);
909 			curscr->wattr |= WA_RIGHT;
910 		}
911 		if (on & WA_HORIZONTAL && enter_horizontal_hl_mode != NULL)
912 		{
913 			tputs(enter_horizontal_hl_mode, 0, __cputchar);
914 			curscr->wattr |= WA_HORIZONTAL;
915 		}
916 		if (on & WA_VERTICAL && enter_vertical_hl_mode != NULL)
917 		{
918 			tputs(enter_vertical_hl_mode, 0, __cputchar);
919 			curscr->wattr |= WA_VERTICAL;
920 		}
921 #endif /* HAVE_WCHAR */
922 	}
923 
924 	/* Enter/exit altcharset mode as appropriate. */
925 	if (on & __ALTCHARSET && enter_alt_charset_mode != NULL &&
926 	    exit_alt_charset_mode != NULL) {
927 		tputs(enter_alt_charset_mode, 0, __cputchar);
928 		curscr->wattr |= __ALTCHARSET;
929 	}
930 }
931 
932 static void
933 putattr_out(__LDATA *nsp)
934 {
935 
936 	if (underline_char &&
937 	    ((nsp->attr & __STANDOUT) || (nsp->attr & __UNDERSCORE)))
938 	{
939 		__cputchar('\b');
940 		tputs(underline_char, 0, __cputchar);
941 	}
942 }
943 
944 static int
945 putch(__LDATA *nsp, __LDATA *csp, int wy, int wx)
946 {
947 
948 	if (csp != NULL)
949 		putattr(nsp);
950 
951 	if (!_cursesi_screen->curwin && csp) {
952 		csp->attr = nsp->attr;
953 		csp->ch = nsp->ch;
954 #ifdef HAVE_WCHAR
955 		if (_cursesi_copy_nsp(nsp->nsp, csp) == ERR)
956 			return ERR;
957 #endif /* HAVE_WCHAR */
958 	}
959 
960 #ifndef HAVE_WCHAR
961 	__cputchar((int)nsp->ch);
962 #else
963 	if (WCOL(*nsp) <= 0)
964 		goto out;
965 	__cputwchar((int)nsp->ch);
966 	__CTRACE(__CTRACE_REFRESH,
967 	    "makech: (%d,%d)putwchar(0x%x)\n", wy, wx - 1, nsp->ch);
968 
969 	/* Output non-spacing characters for the cell. */
970 	__cursesi_putnsp(nsp->nsp, wy, wx);
971 out:
972 #endif /* HAVE_WCHAR */
973 
974 	if (csp != NULL)
975 		putattr_out(nsp);
976 	return OK;
977 }
978 
979 static int
980 putchbr(__LDATA *nsp, __LDATA *csp, __LDATA *psp, int wy, int wx)
981 {
982 	int error, cw, pcw;
983 
984 	/* Can safely print to bottom right corner. */
985 	if (!auto_right_margin)
986 		return putch(nsp, csp, wy, wx);
987 
988 	/* Disable auto margins temporarily. */
989 	if (enter_am_mode && exit_am_mode) {
990 		tputs(exit_am_mode, 0, __cputchar);
991 		error = putch(nsp, csp, wy, wx);
992 		tputs(enter_am_mode, 0, __cputchar);
993 		return error;
994 	}
995 
996 	/* We need to insert characters. */
997 #ifdef HAVE_WCHAR
998 	cw = WCOL(*nsp);
999 	pcw = WCOL(*psp);
1000 	if (cw < 1 || pcw < 1)
1001 		return ERR; /* Nothing to insert */
1002 
1003 	/* When inserting a wide character, we need something other than
1004 	 * insert_character. */
1005 	if (pcw > 1 &&
1006 	    !(parm_ich != NULL ||
1007 	    (enter_insert_mode != NULL && exit_insert_mode != NULL)))
1008 		return ERR;
1009 #else
1010 	cw = pcw = 1;
1011 #endif /* HAVE_WCHAR */
1012 
1013 	/* Write the corner character at wx - pcw. */
1014 	__mvcur(wy, wx, wy, wx - pcw, 1);
1015 	if (putch(nsp, csp, wy, wx) == ERR)
1016 		return ERR;
1017 
1018 	/* Move cursor back. */
1019 	__mvcur(wy, wx - pcw + cw, wy, wx - cw, 1);
1020 
1021 	putattr(psp);
1022 
1023 	/* Enter insert mode. */
1024 	if (pcw == 1 && insert_character != NULL)
1025 		tputs(insert_character, 0, __cputchar);
1026 	else if (parm_ich != NULL)
1027 		tputs(tiparm(parm_ich, (long)pcw), 0, __cputchar);
1028 	else if (enter_insert_mode != NULL && exit_insert_mode != NULL)
1029 		tputs(enter_insert_mode, 0, __cputchar);
1030 	else
1031 		return ERR;
1032 
1033 	/* Insert the old character back. */
1034 	error = putch(psp, NULL, wy, wx - pcw);
1035 
1036 	/* Exit insert mode. */
1037 	if (insert_character != NULL || parm_ich != NULL)
1038 		;
1039 	else if (enter_insert_mode != NULL && exit_insert_mode != NULL)
1040 		tputs(exit_insert_mode, 0, __cputchar);
1041 
1042 	putattr_out(psp);
1043 
1044 	return error;
1045 }
1046 
1047 /*
1048  * makech --
1049  *	Make a change on the screen.
1050  */
1051 static int
1052 makech(int wy)
1053 {
1054 	WINDOW	*win;
1055 	static __LDATA blank;
1056 	__LDATA *nsp, *csp, *cp, *cep, *fsp;
1057 	__LINE *wlp;
1058 	size_t	clsp, nlsp;	/* Last space in lines. */
1059 	int	lch, wx, chw;
1060 	const char	*ce;
1061 	attr_t	lspc;		/* Last space colour */
1062 
1063 #ifdef __GNUC__
1064 	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
1065 #endif
1066 	if (_cursesi_screen->curwin)
1067 		win = curscr;
1068 	else
1069 		win = __virtscr;
1070 #ifdef HAVE_WCHAR
1071 	blank.ch = (wchar_t)btowc((int) win->bch);
1072 	blank.attr = 0;
1073 	if (_cursesi_copy_nsp(win->bnsp, &blank) == ERR)
1074 		return ERR;
1075 	SET_WCOL(blank, 1);
1076 #endif /* HAVE_WCHAR */
1077 #ifdef DEBUG
1078 #if HAVE_WCHAR
1079 	{
1080 		int x;
1081 		__LDATA *lp, *vlp;
1082 
1083 		__CTRACE(__CTRACE_REFRESH,
1084 		    "[makech-before]wy=%d,curscr(%p)-__virtscr(%p)\n",
1085 		    wy, curscr, __virtscr);
1086 		for (x = 0; x < curscr->maxx; x++) {
1087 			lp = &curscr->alines[wy]->line[x];
1088 			vlp = &__virtscr->alines[wy]->line[x];
1089 			__CTRACE(__CTRACE_REFRESH,
1090 			    "[%d,%d](%x,%x,%x,%x,%p)-"
1091 			    "(%x,%x,%x,%x,%p)\n",
1092 			    wy, x, lp->ch, lp->attr,
1093 			    win->bch, win->battr, lp->nsp,
1094 			    vlp->ch, vlp->attr,
1095 			    win->bch, win->battr, vlp->nsp);
1096 		}
1097 	}
1098 #endif /* HAVE_WCHAR */
1099 #endif /* DEBUG */
1100 	/* Is the cursor still on the end of the last line? */
1101 	if (wy > 0 && curscr->alines[wy - 1]->flags & __ISPASTEOL) {
1102 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
1103 			_cursesi_screen->ly + 1, 0);
1104 		_cursesi_screen->ly++;
1105 		_cursesi_screen->lx = 0;
1106 	}
1107 	wlp = win->alines[wy];
1108 	wx = *win->alines[wy]->firstchp;
1109 	if (wx < 0)
1110 		wx = 0;
1111 	else
1112 		if (wx >= win->maxx)
1113 			return (OK);
1114 	lch = *win->alines[wy]->lastchp;
1115 	if (lch < 0)
1116 		return OK;
1117 	else
1118 		if (lch >= (int) win->maxx)
1119 			lch = win->maxx - 1;
1120 
1121 	if (_cursesi_screen->curwin) {
1122 		csp = &blank;
1123 		__CTRACE(__CTRACE_REFRESH, "makech: csp is blank\n");
1124 	} else {
1125 		csp = &curscr->alines[wy]->line[wx];
1126 		__CTRACE(__CTRACE_REFRESH,
1127 		    "makech: csp is on curscr:(%d,%d)\n", wy, wx);
1128 	}
1129 
1130 	nsp = fsp = &win->alines[wy]->line[wx];
1131 #ifdef DEBUG
1132 	if (_cursesi_screen->curwin)
1133 		__CTRACE(__CTRACE_REFRESH,
1134 		    "makech: nsp is at curscr:(%d,%d)\n", wy, wx);
1135 	else
1136 		__CTRACE(__CTRACE_REFRESH,
1137 		    "makech: nsp is at __virtscr:(%d,%d)\n", wy, wx);
1138 #endif /* DEBUG */
1139 	if (clr_eol && !_cursesi_screen->curwin) {
1140 		cp = &win->alines[wy]->line[win->maxx - 1];
1141 		lspc = cp->attr & __COLOR;
1142 #ifndef HAVE_WCHAR
1143 		while (cp->ch == ' ' && cp->attr == lspc) /* XXX */
1144 			if (cp-- <= win->alines[wy]->line)
1145 				break;
1146 #else
1147 		while (cp->ch == ( wchar_t )btowc(( int )' ' )
1148 				&& ( cp->attr & WA_ATTRIBUTES ) == lspc)
1149 			if (cp-- <= win->alines[wy]->line)
1150 				break;
1151 #endif /* HAVE_WCHAR */
1152 		if (win->alines[wy]->line > cp)
1153 			nlsp = 0;
1154 		else
1155 			nlsp = cp - win->alines[wy]->line;
1156 	}
1157 	if (!_cursesi_screen->curwin)
1158 		ce = clr_eol;
1159 	else
1160 		ce = NULL;
1161 
1162 	while (wx <= lch) {
1163 #ifndef HAVE_WCHAR
1164 		__CTRACE(__CTRACE_REFRESH, "makech: wx=%d,lch=%d\n", wx, lch);
1165 #else
1166 		__CTRACE(__CTRACE_REFRESH, "makech: nsp=(%x,%x,%x,%x,%p)\n",
1167 			nsp->ch, nsp->attr, win->bch, win->battr, nsp->nsp);
1168 		__CTRACE(__CTRACE_REFRESH, "makech: csp=(%x,%x,%x,%x,%p)\n",
1169 			csp->ch, csp->attr, win->bch, win->battr, csp->nsp);
1170 #endif
1171 		if (!(wlp->flags & __ISFORCED) &&
1172 #ifdef HAVE_WCHAR
1173 		    ((nsp->attr & __WCWIDTH) != __WCWIDTH) &&
1174 #endif
1175 		    celleq(nsp, csp))
1176 		{
1177 			if (wx <= lch) {
1178 				while (wx <= lch && celleq(nsp, csp)) {
1179 					nsp++;
1180 					if (!_cursesi_screen->curwin)
1181 						++csp;
1182 					++wx;
1183 				}
1184 				continue;
1185 			}
1186 			break;
1187 		}
1188 
1189 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
1190 
1191 		__CTRACE(__CTRACE_REFRESH, "makech: 1: wx = %d, ly= %d, "
1192 		    "lx = %d, newy = %d, newx = %d\n",
1193 		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
1194 		_cursesi_screen->ly = wy;
1195 		_cursesi_screen->lx = wx;
1196 		while (wx <= lch &&
1197 		       ((wlp->flags & __ISFORCED) || !celleq(nsp, csp)))
1198 		{
1199 #ifndef HAVE_WCHAR
1200 			if (ce != NULL && wx >= nlsp
1201 			    && nsp->ch == ' ' && nsp->attr == lspc)
1202 #else
1203 			if (ce != NULL && wx >= nlsp
1204 			    && nsp->ch == (wchar_t)btowc((int)' ') /* XXX */
1205 			    && (nsp->attr & WA_ATTRIBUTES) == lspc)
1206 #endif
1207 			{
1208 				/* Check for clear to end-of-line. */
1209 				cep = &curscr->alines[wy]->line[win->maxx - 1];
1210 #ifndef HAVE_WCHAR
1211 				while (cep->ch == ' ' && cep->attr == lspc) /* XXX */
1212 #else
1213 				while (cep->ch == (wchar_t)btowc((int)' ')
1214 				       && (cep->attr & WA_ATTRIBUTES) == lspc)
1215 #endif /* HAVE_WCHAR */
1216 					if (cep-- <= csp)
1217 						break;
1218 				if (cep > (curscr->alines[wy]->line + win->begx * __LDATASIZE))
1219 					clsp = cep - curscr->alines[wy]->line -
1220 					win->begx * __LDATASIZE;
1221 				else
1222 					clsp = 0;
1223 				__CTRACE(__CTRACE_REFRESH,
1224 				    "makech: clsp = %zu, nlsp = %zu\n",
1225 				    clsp, nlsp);
1226 				__CTRACE(__CTRACE_REFRESH,
1227 				    "makech: line = %p, cep = %p, begx = %u\n",
1228 				    curscr->alines[wy]->line, cep, win->begx);
1229 				if (((clsp - nlsp >= strlen(ce) &&
1230 				    clsp < win->maxx * __LDATASIZE) ||
1231 				    wy == win->maxy - 1) &&
1232 				    (!(lspc & __COLOR) ||
1233 				    ((lspc & __COLOR) && back_color_erase)))
1234 				{
1235 					__unsetattr(0);
1236 					if (__using_color &&
1237 					    ((lspc & __COLOR) !=
1238 					    (curscr->wattr & __COLOR)))
1239 						__set_color(curscr, lspc &
1240 						    __COLOR);
1241 					tputs(ce, 0, __cputchar);
1242 					_cursesi_screen->lx = wx + win->begx;
1243 					while (wx++ <= clsp) {
1244 						csp->attr = lspc;
1245 #ifndef HAVE_WCHAR
1246 						csp->ch = ' '; /* XXX */
1247 #else
1248 						csp->ch = (wchar_t)btowc((int)' ');
1249 						SET_WCOL( *csp, 1 );
1250 #endif /* HAVE_WCHAR */
1251 						assert(csp != &blank);
1252 						csp++;
1253 					}
1254 					return OK;
1255 				}
1256 				ce = NULL;
1257 			}
1258 
1259 #ifdef HAVE_WCHAR
1260 			chw = WCOL(*nsp);
1261 			if (chw < 0)
1262 				chw = 0; /* match putch() */
1263 #else
1264 			chw = 1;
1265 #endif /* HAVE_WCHAR */
1266 			if (wx + chw >= win->maxx &&
1267 			    wy == win->maxy - 1 && !_cursesi_screen->curwin)
1268 			{
1269 				if (win->flags & __ENDLINE)
1270 					__unsetattr(1);
1271 				if (!(win->flags & __SCROLLWIN)) {
1272 					int e;
1273 
1274 					if (win->flags & __SCROLLOK)
1275 						e = putch(nsp, csp, wy, wx);
1276 					else
1277 						e = putchbr(nsp, csp,
1278 						    nsp == fsp ? NULL : nsp - 1,
1279 						    wy, wx);
1280 					if (e == ERR)
1281 						return ERR;
1282 				}
1283 				if (wx + chw < curscr->maxx) {
1284 					domvcur(win,
1285 					    _cursesi_screen->ly, wx,
1286 					    (int)(win->maxy - 1),
1287 					    (int)(win->maxx - 1));
1288 				}
1289 				_cursesi_screen->ly = win->maxy - 1;
1290 				_cursesi_screen->lx = win->maxx - 1;
1291 				return OK;
1292 			}
1293 			if (wx + chw < win->maxx || wy < win->maxy - 1 ||
1294 			    !(win->flags & __SCROLLWIN))
1295 			{
1296 				if (putch(nsp, csp, wy, wx) == ERR)
1297 					return ERR;
1298 				if (!_cursesi_screen->curwin) {
1299 					assert(csp != &blank);
1300 					csp++;
1301 				}
1302 			} else {
1303 				putattr(nsp);
1304 				putattr_out(nsp);
1305 			}
1306 			wx += chw;
1307 			nsp++;
1308 			__CTRACE(__CTRACE_REFRESH,
1309 			    "makech: 2: wx = %d, lx = %d\n",
1310 			    wx, _cursesi_screen->lx);
1311 		}
1312 		if (_cursesi_screen->lx == wx)	/* If no change. */
1313 			break;
1314 		_cursesi_screen->lx = wx;
1315 		if (_cursesi_screen->lx >= COLS && auto_right_margin)
1316 			_cursesi_screen->lx = COLS - 1;
1317 		else
1318 			if (wx >= win->maxx) {
1319 				domvcur(win,
1320 					_cursesi_screen->ly,
1321 					_cursesi_screen->lx,
1322 					_cursesi_screen->ly,
1323 					(int)(win->maxx - 1));
1324 				_cursesi_screen->lx = win->maxx - 1;
1325 			}
1326 		__CTRACE(__CTRACE_REFRESH, "makech: 3: wx = %d, lx = %d\n",
1327 		    wx, _cursesi_screen->lx);
1328 	}
1329 #ifdef DEBUG
1330 #if HAVE_WCHAR
1331 	{
1332 		int x;
1333 		__LDATA *lp, *vlp;
1334 
1335 		__CTRACE(__CTRACE_REFRESH,
1336 		    "makech-after: curscr(%p)-__virtscr(%p)\n",
1337 		    curscr, __virtscr );
1338 		for (x = 0; x < curscr->maxx; x++) {
1339 			lp = &curscr->alines[wy]->line[x];
1340 			vlp = &__virtscr->alines[wy]->line[x];
1341 			__CTRACE(__CTRACE_REFRESH,
1342 			    "[%d,%d](%x,%x,%x,%x,%p)-"
1343 			    "(%x,%x,%x,%x,%p)\n",
1344 			    wy, x, lp->ch, lp->attr,
1345 			    win->bch, win->battr, lp->nsp,
1346 			    vlp->ch, vlp->attr,
1347 			    win->bch, win->battr, vlp->nsp);
1348 		}
1349 	}
1350 #endif /* HAVE_WCHAR */
1351 #endif /* DEBUG */
1352 
1353 	return OK;
1354 }
1355 
1356 /*
1357  * domvcur --
1358  *	Do a mvcur, leaving attributes if necessary.
1359  */
1360 static void
1361 domvcur(WINDOW *win, int oy, int ox, int ny, int nx)
1362 {
1363 
1364 	__CTRACE(__CTRACE_REFRESH, "domvcur: (%d,%d)=>(%d,%d) win %p\n",
1365 	    oy, ox, ny, nx, win );
1366 
1367 	__unsetattr(1);
1368 
1369 	/* Don't move the cursor unless we need to. */
1370 	if (oy == ny && ox == nx) {
1371 		/* Check EOL. */
1372 		if (!(win->alines[oy]->flags & __ISPASTEOL))
1373 			return;
1374 	}
1375 
1376 	/* Clear EOL flags. */
1377 	win->alines[oy]->flags &= ~__ISPASTEOL;
1378 	win->alines[ny]->flags &= ~__ISPASTEOL;
1379 
1380 	__mvcur(oy, ox, ny, nx, 1);
1381 }
1382 
1383 /*
1384  * Quickch() attempts to detect a pattern in the change of the window
1385  * in order to optimize the change, e.g., scroll n lines as opposed to
1386  * repainting the screen line by line.
1387  */
1388 
1389 static __LDATA buf[128];
1390 static  unsigned int last_hash;
1391 static  size_t last_hash_len;
1392 #define BLANKSIZE (sizeof(buf) / sizeof(buf[0]))
1393 
1394 static void
1395 quickch(void)
1396 {
1397 #define THRESH		(int) __virtscr->maxy / 4
1398 
1399 	__LINE *clp, *tmp1, *tmp2;
1400 	int	bsize, curs, curw, starts, startw, i, j;
1401 	int	n, target, cur_period, bot, top, sc_region;
1402 	unsigned int	blank_hash;
1403 	attr_t	bcolor;
1404 
1405 #ifdef __GNUC__
1406 	curs = curw = starts = startw = 0;	/* XXX gcc -Wuninitialized */
1407 #endif
1408 	/*
1409 	 * Find how many lines from the top of the screen are unchanged.
1410 	 */
1411 	for (top = 0; top < __virtscr->maxy; top++) {
1412 		if (__virtscr->alines[top]->flags & __ISDIRTY &&
1413 		    (__virtscr->alines[top]->hash != curscr->alines[top]->hash ||
1414 		     !lineeq(__virtscr->alines[top]->line,
1415 			     curscr->alines[top]->line,
1416 			     (size_t) __virtscr->maxx)))
1417 			break;
1418 		else
1419 			__virtscr->alines[top]->flags &= ~__ISDIRTY;
1420 	}
1421 	/*
1422 	 * Find how many lines from bottom of screen are unchanged.
1423 	 */
1424 	for (bot = __virtscr->maxy - 1; bot >= 0; bot--) {
1425 		if (__virtscr->alines[bot]->flags & __ISDIRTY &&
1426 		    (__virtscr->alines[bot]->hash != curscr->alines[bot]->hash ||
1427 		     !lineeq(__virtscr->alines[bot]->line,
1428 			     curscr->alines[bot]->line,
1429 			     (size_t) __virtscr->maxx)))
1430 			break;
1431 		else
1432 			__virtscr->alines[bot]->flags &= ~__ISDIRTY;
1433 	}
1434 
1435 	/*
1436 	 * Work round an xterm bug where inserting lines causes all the
1437 	 * inserted lines to be covered with the background colour we
1438 	 * set on the first line (even if we unset it for subsequent
1439 	 * lines).
1440 	 */
1441 	bcolor = __virtscr->alines[min(top,
1442 	    __virtscr->maxy - 1)]->line[0].attr & __COLOR;
1443 	for (i = top + 1, j = 0; i < bot; i++) {
1444 		if ((__virtscr->alines[i]->line[0].attr & __COLOR) != bcolor) {
1445 			bcolor = __virtscr->alines[i]->line[__virtscr->maxx].
1446 			    attr & __COLOR;
1447 			j = i - top;
1448 		} else
1449 			break;
1450 	}
1451 	top += j;
1452 
1453 #ifdef NO_JERKINESS
1454 	/*
1455 	 * If we have a bottom unchanged region return.  Scrolling the
1456 	 * bottom region up and then back down causes a screen jitter.
1457 	 * This will increase the number of characters sent to the screen
1458 	 * but it looks better.
1459 	 */
1460 	if (bot < __virtscr->maxy - 1)
1461 		return;
1462 #endif				/* NO_JERKINESS */
1463 
1464 	/*
1465 	 * Search for the largest block of text not changed.
1466 	 * Invariants of the loop:
1467 	 * - Startw is the index of the beginning of the examined block in
1468 	 *   __virtscr.
1469 	 * - Starts is the index of the beginning of the examined block in
1470 	 *   curscr.
1471 	 * - Curw is the index of one past the end of the exmined block in
1472 	 *   __virtscr.
1473 	 * - Curs is the index of one past the end of the exmined block in
1474 	 *   curscr.
1475 	 * - bsize is the current size of the examined block.
1476 	*/
1477 
1478 	for (bsize = bot - top; bsize >= THRESH; bsize--) {
1479 		for (startw = top; startw <= bot - bsize; startw++)
1480 			for (starts = top; starts <= bot - bsize; starts++) {
1481 				for (curw = startw, curs = starts;
1482 				    curs < starts + bsize; curw++, curs++)
1483 					if (__virtscr->alines[curw]->hash !=
1484 					    curscr->alines[curs]->hash)
1485 						break;
1486 				if (curs != starts + bsize)
1487 					continue;
1488 				for (curw = startw, curs = starts;
1489 					curs < starts + bsize; curw++, curs++)
1490 					if (!lineeq(__virtscr->alines[curw]->line,
1491 						    curscr->alines[curs]->line,
1492 						    (size_t) __virtscr->maxx))
1493 						break;
1494 				if (curs == starts + bsize)
1495 					goto done;
1496 			}
1497 	}
1498 done:
1499 
1500 	/* Did not find anything */
1501 	if (bsize < THRESH)
1502 		return;
1503 
1504 	__CTRACE(__CTRACE_REFRESH, "quickch:bsize=%d, starts=%d, startw=%d, "
1505 	    "curw=%d, curs=%d, top=%d, bot=%d\n",
1506 	    bsize, starts, startw, curw, curs, top, bot);
1507 
1508 	/*
1509 	 * Make sure that there is no overlap between the bottom and top
1510 	 * regions and the middle scrolled block.
1511 	 */
1512 	if (bot < curs)
1513 		bot = curs - 1;
1514 	if (top > starts)
1515 		top = starts;
1516 
1517 	n = startw - starts;
1518 
1519 #ifdef DEBUG
1520 	__CTRACE(__CTRACE_REFRESH, "#####################################\n");
1521 	for (i = 0; i < curscr->maxy; i++) {
1522 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1523 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n", curscr->alines[i]->hash);
1524 		for (j = 0; j < curscr->maxx; j++)
1525 			__CTRACE(__CTRACE_REFRESH, "%c",
1526 			    curscr->alines[i]->line[j].ch);
1527 		__CTRACE(__CTRACE_REFRESH, "\n");
1528 		__CTRACE(__CTRACE_REFRESH, " attr:");
1529 		for (j = 0; j < curscr->maxx; j++)
1530 			__CTRACE(__CTRACE_REFRESH, " %x",
1531 			    curscr->alines[i]->line[j].attr);
1532 		__CTRACE(__CTRACE_REFRESH, "\n");
1533 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1534 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
1535 		    __virtscr->alines[i]->hash);
1536 		__CTRACE(__CTRACE_REFRESH, " 0x%x ",
1537 		    __virtscr->alines[i]->flags);
1538 		for (j = 0; j < __virtscr->maxx; j++)
1539 			__CTRACE(__CTRACE_REFRESH, "%c",
1540 			    __virtscr->alines[i]->line[j].ch);
1541 		__CTRACE(__CTRACE_REFRESH, "\n");
1542 		__CTRACE(__CTRACE_REFRESH, " attr:");
1543 		for (j = 0; j < __virtscr->maxx; j++)
1544 			__CTRACE(__CTRACE_REFRESH, " %x",
1545 			    __virtscr->alines[i]->line[j].attr);
1546 		__CTRACE(__CTRACE_REFRESH, "\n");
1547 	}
1548 #endif
1549 
1550 #ifndef HAVE_WCHAR
1551 	if (buf[0].ch != ' ') {
1552 		for (i = 0; i < BLANKSIZE; i++) {
1553 			buf[i].ch = ' ';
1554 			buf[i].attr = 0;
1555 		}
1556 	}
1557 #else
1558 	if (buf[0].ch != (wchar_t)btowc((int)curscr->bch )) {
1559 		for (i = 0; i < BLANKSIZE; i++) {
1560 			buf[i].ch = (wchar_t)btowc((int)curscr->bch);
1561 			if (_cursesi_copy_nsp(curscr->bnsp, &buf[i]) == ERR)
1562 				return;
1563 			buf[i].attr = 0;
1564 			SET_WCOL(buf[i], 1);
1565 		}
1566 	}
1567 #endif /* HAVE_WCHAR */
1568 
1569 	if (__virtscr->maxx != last_hash_len) {
1570 		blank_hash = 0;
1571 		for (i = __virtscr->maxx; i > BLANKSIZE; i -= BLANKSIZE) {
1572 			blank_hash = __hash_more(buf, sizeof(buf), blank_hash);
1573 		}
1574 		blank_hash = __hash_more((char *)(void *)buf,
1575 		    i * sizeof(buf[0]), blank_hash);
1576 		/* cache result in static data - screen width doesn't change often */
1577 		last_hash_len = __virtscr->maxx;
1578 		last_hash = blank_hash;
1579 	} else
1580 		blank_hash = last_hash;
1581 
1582 	/*
1583 	 * Perform the rotation to maintain the consistency of curscr.
1584 	 * This is hairy since we are doing an *in place* rotation.
1585 	 * Invariants of the loop:
1586 	 * - I is the index of the current line.
1587 	 * - Target is the index of the target of line i.
1588 	 * - Tmp1 points to current line (i).
1589 	 * - Tmp2 and points to target line (target);
1590 	 * - Cur_period is the index of the end of the current period.
1591 	 *   (see below).
1592 	 *
1593 	 * There are 2 major issues here that make this rotation non-trivial:
1594 	 * 1.  Scrolling in a scrolling region bounded by the top
1595 	 *     and bottom regions determined (whose size is sc_region).
1596 	 * 2.  As a result of the use of the mod function, there may be a
1597 	 *     period introduced, i.e., 2 maps to 4, 4 to 6, n-2 to 0, and
1598 	 *     0 to 2, which then causes all odd lines not to be rotated.
1599 	 *     To remedy this, an index of the end ( = beginning) of the
1600 	 *     current 'period' is kept, cur_period, and when it is reached,
1601 	 *     the next period is started from cur_period + 1 which is
1602 	 *     guaranteed not to have been reached since that would mean that
1603 	 *     all records would have been reached. (think about it...).
1604 	 *
1605 	 * Lines in the rotation can have 3 attributes which are marked on the
1606 	 * line so that curscr is consistent with the visual screen.
1607 	 * 1.  Not dirty -- lines inside the scrolled block, top region or
1608 	 *                  bottom region.
1609 	 * 2.  Blank lines -- lines in the differential of the scrolling
1610 	 *		      region adjacent to top and bot regions
1611 	 *                    depending on scrolling direction.
1612 	 * 3.  Dirty line -- all other lines are marked dirty.
1613 	 */
1614 	sc_region = bot - top + 1;
1615 	i = top;
1616 	tmp1 = curscr->alines[top];
1617 	cur_period = top;
1618 	for (j = top; j <= bot; j++) {
1619 		target = (i - top + n + sc_region) % sc_region + top;
1620 		tmp2 = curscr->alines[target];
1621 		curscr->alines[target] = tmp1;
1622 		/* Mark block as clean and blank out scrolled lines. */
1623 		clp = curscr->alines[target];
1624 		__CTRACE(__CTRACE_REFRESH,
1625 		    "quickch: n=%d startw=%d curw=%d i = %d target=%d ",
1626 		    n, startw, curw, i, target);
1627 		if ((target >= startw && target < curw) || target < top
1628 		    || target > bot)
1629 		{
1630 			__CTRACE(__CTRACE_REFRESH, " notdirty\n");
1631 			__virtscr->alines[target]->flags &= ~__ISDIRTY;
1632 		} else
1633 			if ((n > 0 && target >= top && target < top + n) ||
1634 			    (n < 0 && target <= bot && target > bot + n))
1635 			{
1636 				if (clp->hash != blank_hash ||
1637 				    !lineeq(clp->line, clp->line + 1,
1638 					    (__virtscr->maxx - 1)) ||
1639 				    !celleq(clp->line, buf))
1640 				{
1641 					for (i = __virtscr->maxx;
1642 					    i > BLANKSIZE;
1643 					    i -= BLANKSIZE) {
1644 						(void) memcpy(clp->line + i -
1645 						    BLANKSIZE, buf, sizeof(buf));
1646 					}
1647 					(void)memcpy(clp->line, buf,
1648 					    i * sizeof(buf[0]));
1649 					__CTRACE(__CTRACE_REFRESH,
1650 					    " blanked out: dirty\n");
1651 					clp->hash = blank_hash;
1652 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1653 				} else {
1654 					__CTRACE(__CTRACE_REFRESH,
1655 					    " -- blank line already: dirty\n");
1656 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1657 				}
1658 			} else {
1659 				__CTRACE(__CTRACE_REFRESH, " -- dirty\n");
1660 				__touchline(__virtscr, target, 0,
1661 				    (int)__virtscr->maxx - 1);
1662 			}
1663 		if (target == cur_period) {
1664 			i = target + 1;
1665 			tmp1 = curscr->alines[i];
1666 			cur_period = i;
1667 		} else {
1668 			tmp1 = tmp2;
1669 			i = target;
1670 		}
1671 	}
1672 #ifdef DEBUG
1673 	__CTRACE(__CTRACE_REFRESH, "$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
1674 	for (i = 0; i < curscr->maxy; i++) {
1675 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1676 		for (j = 0; j < curscr->maxx; j++)
1677 			__CTRACE(__CTRACE_REFRESH, "%c",
1678 			    curscr->alines[i]->line[j].ch);
1679 		__CTRACE(__CTRACE_REFRESH, "\n");
1680 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1681 		for (j = 0; j < __virtscr->maxx; j++)
1682 			__CTRACE(__CTRACE_REFRESH, "%c",
1683 			    __virtscr->alines[i]->line[j].ch);
1684 		__CTRACE(__CTRACE_REFRESH, "\n");
1685 	}
1686 #endif
1687 	if (n != 0)
1688 		scrolln(starts, startw, curs, bot, top);
1689 }
1690 
1691 /*
1692  * scrolln --
1693  *	Scroll n lines, where n is starts - startw.
1694  */
1695 static void /* ARGSUSED */
1696 scrolln(int starts, int startw, int curs, int bot, int top)
1697 {
1698 	int	i, oy, ox, n;
1699 
1700 	oy = curscr->cury;
1701 	ox = curscr->curx;
1702 	n = starts - startw;
1703 
1704 	/*
1705 	 * XXX
1706 	 * The initial tests that set __noqch don't let us reach here unless
1707 	 * we have either cs + ho + SF/sf/SR/sr, or AL + DL.  SF/sf and SR/sr
1708 	 * scrolling can only shift the entire scrolling region, not just a
1709 	 * part of it, which means that the quickch() routine is going to be
1710 	 * sadly disappointed in us if we don't have cs as well.
1711 	 *
1712 	 * If cs, ho and SF/sf are set, can use the scrolling region.  Because
1713 	 * the cursor position after cs is undefined, we need ho which gives us
1714 	 * the ability to move to somewhere without knowledge of the current
1715 	 * location of the cursor.  Still call __mvcur() anyway, to update its
1716 	 * idea of where the cursor is.
1717 	 *
1718 	 * When the scrolling region has been set, the cursor has to be at the
1719 	 * last line of the region to make the scroll happen.
1720 	 *
1721 	 * Doing SF/SR or AL/DL appears faster on the screen than either sf/sr
1722 	 * or AL/DL, and, some terminals have AL/DL, sf/sr, and cs, but not
1723 	 * SF/SR.  So, if we're scrolling almost all of the screen, try and use
1724 	 * AL/DL, otherwise use the scrolling region.  The "almost all" is a
1725 	 * shameless hack for vi.
1726 	 */
1727 	if (n > 0) {
1728 		if (change_scroll_region != NULL && cursor_home != NULL &&
1729 		    (parm_index != NULL ||
1730 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1731 		    top > 3 || bot + 3 < __virtscr->maxy) &&
1732 		    scroll_forward != NULL)))
1733 		{
1734 			tputs(tiparm(change_scroll_region, top, bot),
1735 			    0, __cputchar);
1736 			__mvcur(oy, ox, 0, 0, 1);
1737 			tputs(cursor_home, 0, __cputchar);
1738 			__mvcur(0, 0, bot, 0, 1);
1739 			if (parm_index != NULL)
1740 				tputs(tiparm(parm_index, n),
1741 				    0, __cputchar);
1742 			else
1743 				for (i = 0; i < n; i++)
1744 					tputs(scroll_forward, 0, __cputchar);
1745 			tputs(tiparm(change_scroll_region,
1746 			    0, (int)__virtscr->maxy - 1), 0, __cputchar);
1747 			__mvcur(bot, 0, 0, 0, 1);
1748 			tputs(cursor_home, 0, __cputchar);
1749 			__mvcur(0, 0, oy, ox, 1);
1750 			return;
1751 		}
1752 
1753 		/* Scroll up the block. */
1754 		if (parm_index != NULL && top == 0) {
1755 			__mvcur(oy, ox, bot, 0, 1);
1756 			tputs(tiparm(parm_index, n), 0, __cputchar);
1757 		} else
1758 			if (parm_delete_line != NULL) {
1759 				__mvcur(oy, ox, top, 0, 1);
1760 				tputs(tiparm(parm_delete_line, n),
1761 				    0, __cputchar);
1762 			} else
1763 				if (delete_line != NULL) {
1764 					__mvcur(oy, ox, top, 0, 1);
1765 					for (i = 0; i < n; i++)
1766 						tputs(delete_line, 0,
1767 						    __cputchar);
1768 				} else
1769 					if (scroll_forward != NULL && top == 0) {
1770 						__mvcur(oy, ox, bot, 0, 1);
1771 						for (i = 0; i < n; i++)
1772 							tputs(scroll_forward, 0,
1773 							    __cputchar);
1774 					} else
1775 						abort();
1776 
1777 		/* Push down the bottom region. */
1778 		__mvcur(top, 0, bot - n + 1, 0, 1);
1779 		if (parm_insert_line != NULL)
1780 			tputs(tiparm(parm_insert_line, n), 0, __cputchar);
1781 		else {
1782 			if (insert_line != NULL) {
1783 				for (i = 0; i < n; i++)
1784 					tputs(insert_line, 0, __cputchar);
1785 			} else
1786 				abort();
1787 		}
1788 		__mvcur(bot - n + 1, 0, oy, ox, 1);
1789 	} else {
1790 		/*
1791 		 * !!!
1792 		 * n < 0
1793 		 *
1794 		 * If cs, ho and SR/sr are set, can use the scrolling region.
1795 		 * See the above comments for details.
1796 		 */
1797 		if (change_scroll_region != NULL && cursor_home != NULL &&
1798 		    (parm_rindex != NULL ||
1799 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1800 		    top > 3 ||
1801 		    bot + 3 < __virtscr->maxy) && scroll_reverse != NULL)))
1802 		{
1803 			tputs(tiparm(change_scroll_region, top, bot),
1804 			    0, __cputchar);
1805 			__mvcur(oy, ox, 0, 0, 1);
1806 			tputs(cursor_home, 0, __cputchar);
1807 			__mvcur(0, 0, top, 0, 1);
1808 
1809 			if (parm_rindex != NULL)
1810 				tputs(tiparm(parm_rindex, -n),
1811 				    0, __cputchar);
1812 			else
1813 				for (i = n; i < 0; i++)
1814 					tputs(scroll_reverse, 0, __cputchar);
1815 			tputs(tiparm(change_scroll_region,
1816 			    0, (int) __virtscr->maxy - 1), 0, __cputchar);
1817 			__mvcur(top, 0, 0, 0, 1);
1818 			tputs(cursor_home, 0, __cputchar);
1819 			__mvcur(0, 0, oy, ox, 1);
1820 			return;
1821 		}
1822 
1823 		/* Preserve the bottom lines. */
1824 		__mvcur(oy, ox, bot + n + 1, 0, 1);
1825 		if (parm_rindex != NULL && bot == __virtscr->maxy)
1826 			tputs(tiparm(parm_rindex, -n), 0, __cputchar);
1827 		else {
1828 			if (parm_delete_line != NULL)
1829 				tputs(tiparm(parm_delete_line, -n),
1830 				    0, __cputchar);
1831 			else {
1832 				if (delete_line != NULL)
1833 					for (i = n; i < 0; i++)
1834 						tputs(delete_line,
1835 						    0, __cputchar);
1836 				else {
1837 					if (scroll_reverse != NULL &&
1838 					    bot == __virtscr->maxy)
1839 						for (i = n; i < 0; i++)
1840 							tputs(scroll_reverse, 0,
1841 							    __cputchar);
1842 					else
1843 						abort();
1844 				}
1845 			}
1846 		}
1847 		/* Scroll the block down. */
1848 		__mvcur(bot + n + 1, 0, top, 0, 1);
1849 		if (parm_insert_line != NULL)
1850 			tputs(tiparm(parm_insert_line, -n), 0, __cputchar);
1851 		else
1852 			if (insert_line != NULL)
1853 				for (i = n; i < 0; i++)
1854 					tputs(insert_line, 0, __cputchar);
1855 			else
1856 				abort();
1857 		__mvcur(top, 0, oy, ox, 1);
1858 	}
1859 }
1860 
1861 /*
1862  * __unsetattr --
1863  *	Unset attributes on curscr.  Leave standout, attribute and colour
1864  *	modes if necessary (!ms).  Always leave altcharset (xterm at least
1865  *	ignores a cursor move if we don't).
1866  */
1867 void /* ARGSUSED */
1868 __unsetattr(int checkms)
1869 {
1870 	int	isms;
1871 
1872 	if (checkms) {
1873 		if (!move_standout_mode)
1874 			isms = 1;
1875 		else
1876 			isms = 0;
1877 	} else
1878 		isms = 1;
1879 	__CTRACE(__CTRACE_REFRESH,
1880 	    "__unsetattr: checkms = %d, ms = %s, wattr = %08x\n",
1881 	    checkms, move_standout_mode ? "TRUE" : "FALSE", curscr->wattr);
1882 
1883 	/*
1884 	 * Don't leave the screen in standout mode (check against ms).  Check
1885 	 * to see if we also turn off underscore, attributes and colour.
1886 	 */
1887 	if (curscr->wattr & __STANDOUT && isms) {
1888 		tputs(exit_standout_mode, 0, __cputchar);
1889 		curscr->wattr &= __mask_se;
1890 	}
1891 	/*
1892 	 * Don't leave the screen in underscore mode (check against ms).
1893 	 * Check to see if we also turn off attributes.  Assume that we
1894 	 * also turn off colour.
1895 	 */
1896 	if (curscr->wattr & __UNDERSCORE && isms) {
1897 		tputs(exit_underline_mode, 0, __cputchar);
1898 		curscr->wattr &= __mask_ue;
1899 	}
1900 	/*
1901 	 * Don't leave the screen with attributes set (check against ms).
1902 	 * Assume that also turn off colour.
1903 	 */
1904 	if (curscr->wattr & __TERMATTR && isms) {
1905 		tputs(exit_attribute_mode, 0, __cputchar);
1906 		curscr->wattr &= __mask_me;
1907 	}
1908 	/* Don't leave the screen with altcharset set (don't check ms). */
1909 	if (curscr->wattr & __ALTCHARSET) {
1910 		tputs(exit_alt_charset_mode, 0, __cputchar);
1911 		curscr->wattr &= ~__ALTCHARSET;
1912 	}
1913 	/* Don't leave the screen with colour set (check against ms). */
1914 	if (__using_color && isms)
1915 		__unset_color(curscr);
1916 }
1917 
1918 #ifdef HAVE_WCHAR
1919 /* compare two cells on screen, must have the same foreground/background,
1920  * and the same sequence of non-spacing characters */
1921 static int
1922 celleq(__LDATA *x, __LDATA *y)
1923 {
1924 	nschar_t *xnp = x->nsp, *ynp = y->nsp;
1925 	int ret = ( x->ch == y->ch ) && ( x->attr == y->attr );
1926 
1927 	if (!ret)
1928 		return 0;
1929 	if (!xnp && !ynp)
1930 		return 1;
1931 	if ((xnp && !ynp) || (!xnp && ynp))
1932 		return 0;
1933 
1934 	while (xnp && ynp) {
1935 		if (xnp->ch != ynp->ch)
1936 			return 0;
1937 		xnp = xnp->next;
1938 		ynp = ynp->next;
1939 	}
1940 	return !xnp && !ynp;
1941 }
1942 
1943 /* compare two line segments */
1944 static int
1945 lineeq(__LDATA *xl, __LDATA *yl, size_t len)
1946 {
1947 	int i = 0;
1948 	__LDATA *xp = xl, *yp = yl;
1949 
1950 	for (i = 0; i < len; i++, xp++, yp++) {
1951 		if (!celleq(xp, yp))
1952 			return 0;
1953 	}
1954 	return 1;
1955 }
1956 
1957 /*
1958  * Output the non-spacing characters associated with the given character
1959  * cell to the screen.
1960  */
1961 
1962 void
1963 __cursesi_putnsp(nschar_t *nsp, const int wy, const int wx)
1964 {
1965 	nschar_t *p;
1966 
1967 	/* this shuts up gcc warnings about wx and wy not being used */
1968 	if (wx > wy) {
1969 	}
1970 
1971 	p = nsp;
1972 	while (p != NULL) {
1973 		__cputwchar((int)p->ch);
1974 		__CTRACE(__CTRACE_REFRESH,
1975 		    "_cursesi_putnsp: (%d,%d) non-spacing putwchar(0x%x)\n",
1976 		    wy, wx - 1, p->ch);
1977 		p = p->next;
1978 	}
1979 }
1980 
1981 #endif /* HAVE_WCHAR */
1982