xref: /netbsd-src/lib/libcurses/refresh.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: refresh.c,v 1.102 2018/11/30 04:38:14 roy 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 1.102 2018/11/30 04:38:14 roy Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #include <poll.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "curses.h"
46 #include "curses_private.h"
47 
48 static void	domvcur(const WINDOW *, int, int, int, int);
49 static void	putattr(__LDATA *);
50 static void	putattr_out(__LDATA *);
51 static int	putch(__LDATA *, __LDATA *, int, int);
52 static int	putchbr(__LDATA *, __LDATA *, __LDATA *, int, int);
53 static int	makech(int);
54 static void	quickch(void);
55 static void	scrolln(int, int, int, int, int);
56 
57 static int	_wnoutrefresh(WINDOW *, int, int, int, int, int, int);
58 
59 #ifdef HAVE_WCHAR
60 static int celleq(__LDATA *, __LDATA *);
61 static int lineeq(__LDATA *, __LDATA *, size_t);
62 #else  /* !HAVE_WCHAR */
63 static inline int
64 celleq(__LDATA *x, __LDATA *y)
65 {
66 	return memcmp(x, y, sizeof(__LDATA)) == 0;
67 }
68 
69 static int
70 lineeq(__LDATA *xl, __LDATA *yl, size_t len)
71 {
72 	return memcmp(xl, yl, len * __LDATASIZE) == 0;
73 }
74 #endif /* HAVE_WCHAR */
75 
76 #define	CHECK_INTERVAL		5 /* Change N lines before checking typeahead */
77 
78 #ifndef _CURSES_USE_MACROS
79 
80 /*
81  * refresh --
82  *	Make the current screen look like "stdscr" over the area covered by
83  *	stdscr.
84  */
85 int
86 refresh(void)
87 {
88 
89 	return wrefresh(stdscr);
90 }
91 
92 #endif
93 
94 /*
95  * wnoutrefresh --
96  *	Add the contents of "win" to the virtual window.
97  */
98 int
99 wnoutrefresh(WINDOW *win)
100 {
101 
102 #ifdef DEBUG
103 	__CTRACE(__CTRACE_REFRESH, "wnoutrefresh: win %p\n", win);
104 #endif
105 
106 	return _wnoutrefresh(win, 0, 0, win->begy, win->begx,
107 	    win->maxy, win->maxx);
108 }
109 
110 /*
111  * pnoutrefresh --
112  *	Add the contents of "pad" to the virtual window.
113  */
114 int
115 pnoutrefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
116 	     int smaxy, int smaxx)
117 {
118 	int pmaxy, pmaxx;
119 
120 #ifdef DEBUG
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 #endif
127 
128 	/* SUS says if these are negative, they should be treated as zero */
129 	if (pbegy < 0)
130 		pbegy = 0;
131 	if (pbegx < 0)
132 		pbegx = 0;
133 	if (sbegy < 0)
134 		sbegy = 0;
135 	if (sbegx < 0)
136 		sbegx = 0;
137 
138 	/* Calculate rectangle on pad - used by _wnoutrefresh */
139 	pmaxy = pbegy + smaxy - sbegy + 1;
140 	pmaxx = pbegx + smaxx - sbegx + 1;
141 
142 	/* Check rectangle fits in pad */
143 	if (pmaxy > pad->maxy - pad->begy)
144 		pmaxy = pad->maxy - pad->begy;
145 	if (pmaxx > pad->maxx - pad->begx)
146 		pmaxx = pad->maxx - pad->begx;
147 
148 	if (smaxy - sbegy < 0 || smaxx - sbegx < 0 )
149 		return ERR;
150 
151 	return _wnoutrefresh(pad,
152 	    pad->begy + pbegy, pad->begx + pbegx, pad->begy + sbegy,
153 	    pad->begx + sbegx, pmaxy, pmaxx);
154 }
155 
156 /*
157  * _wnoutrefresh --
158  *	Does the grunt work for wnoutrefresh to the given screen.
159  *	Copies the part of the window given by the rectangle
160  *	(begy, begx) to (maxy, maxx) at screen position (wbegy, wbegx).
161  */
162 static int
163 _wnoutrefresh(WINDOW *win, int begy, int begx, int wbegy, int wbegx,
164               int maxy, int maxx)
165 {
166 	SCREEN *screen = win->screen;
167 	short	sy, wy, wx, y_off, x_off, mx, dy_off, dx_off, endy;
168 	__LINE	*wlp, *vlp, *dwlp;
169 	WINDOW	*sub_win, *orig, *swin, *dwin;
170 
171 #ifdef DEBUG
172 	__CTRACE(__CTRACE_REFRESH, "_wnoutrefresh: win %p, flags 0x%08x\n",
173 	    win, win->flags);
174 	__CTRACE(__CTRACE_REFRESH,
175 	    "_wnoutrefresh: (%d, %d), (%d, %d), (%d, %d)\n",
176 	    begy, begx, wbegy, wbegx, maxy, maxx);
177 #endif
178 
179 	if (screen->curwin)
180 		return OK;
181 
182 	swin = dwin = win;
183 	if (win->flags & __ISDERWIN)
184 		swin = win->orig;
185 
186 	/*
187 	 * Recurse through any sub-windows, mark as dirty lines on the parent
188 	 * window that are dirty on the sub-window and clear the dirty flag on
189 	 * the sub-window.
190 	 */
191 	if (dwin->orig == 0) {
192 		orig = dwin;
193 		for (sub_win = dwin->nextp; sub_win != orig;
194 		    sub_win = sub_win->nextp) {
195 			if (sub_win->flags & __ISDERWIN)
196 				continue;
197 #ifdef DEBUG
198 			__CTRACE(__CTRACE_REFRESH,
199 			    "wnout_refresh: win %p, sub_win %p\n",
200 			    orig, sub_win);
201 #endif
202 			for (sy = 0; sy < sub_win->maxy; sy++) {
203 				if (sub_win->alines[sy]->flags & __ISDIRTY) {
204 					orig->alines[sy + sub_win->begy - orig->begy]->flags
205 					    |= __ISDIRTY;
206 					sub_win->alines[sy]->flags
207 					    &= ~__ISDIRTY;
208 				}
209 				if (sub_win->alines[sy]->flags & __ISFORCED) {
210 					orig->alines[sy + sub_win->begy - orig->begy]->flags
211 					    |= __ISFORCED;
212 					sub_win->alines[sy]->flags
213 					    &= ~__ISFORCED;
214 				}
215 			}
216 		}
217 	}
218 
219 	/* Check that cursor position on "win" is valid for "__virtscr" */
220 	if (dwin->cury + wbegy - begy < screen->__virtscr->maxy &&
221 	    dwin->cury + wbegy - begy >= 0 && dwin->cury < maxy - begy)
222 		screen->__virtscr->cury = dwin->cury + wbegy - begy;
223 	if (dwin->curx + wbegx - begx < screen->__virtscr->maxx &&
224 	    dwin->curx + wbegx - begx >= 0 && dwin->curx < maxx - begx)
225 		screen->__virtscr->curx = dwin->curx + wbegx - begx;
226 
227 	/* Copy the window flags from "win" to "__virtscr" */
228 	if (dwin->flags & __CLEAROK) {
229 		if (dwin->flags & __FULLWIN)
230 			screen->__virtscr->flags |= __CLEAROK;
231 		dwin->flags &= ~__CLEAROK;
232 	}
233 	screen->__virtscr->flags &= ~__LEAVEOK;
234 	screen->__virtscr->flags |= dwin->flags;
235 
236 	if ((dwin->flags & __ISDERWIN) != 0)
237 		endy = begy + maxy;
238 	else
239 		endy = maxy;
240 
241 	for (wy = begy, y_off = wbegy, dy_off = 0; wy < endy &&
242 	    y_off < screen->__virtscr->maxy; wy++, y_off++, dy_off++)
243 	{
244 		wlp = swin->alines[wy];
245 		dwlp = dwin->alines[dy_off];
246 #ifdef DEBUG
247 		__CTRACE(__CTRACE_REFRESH,
248 		    "_wnoutrefresh: wy %d\tf %d\tl %d\tflags %x\n",
249 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
250 
251 		if ((dwin->flags & __ISDERWIN) != 0) {
252 			__CTRACE(__CTRACE_REFRESH,
253 			"_wnoutrefresh: derwin wy %d\tf %d\tl %d\tflags %x\n",
254 			dy_off, *dwlp->firstchp, *dwlp->lastchp, dwlp->flags);
255 			__CTRACE(__CTRACE_REFRESH,
256 			"_wnoutrefresh: derwin maxx %d\tch_off %d\n",
257 			dwin->maxx, dwin->ch_off);
258 		}
259 #endif
260 		if (((wlp->flags & (__ISDIRTY | __ISFORCED)) == 0) &&
261 		    ((dwlp->flags & (__ISDIRTY | __ISFORCED)) == 0))
262 			continue;
263 		vlp = screen->__virtscr->alines[y_off];
264 
265 		if ((*wlp->firstchp < maxx + swin->ch_off &&
266 		    *wlp->lastchp >= swin->ch_off) ||
267 		    ((((dwin->flags & __ISDERWIN) != 0) &&
268 		     (*dwlp->firstchp < dwin->maxx + dwin->ch_off &&
269 		      *dwlp->lastchp >= dwin->ch_off))))
270 		{
271 			/* Set start column */
272 			wx = begx;
273 			x_off = wbegx;
274 			dx_off = 0;
275 			/*
276 			 * if a derwin then source change pointers aren't
277 			 * relevant.
278 			 */
279 			if ((dwin->flags & __ISDERWIN) != 0)
280 				mx = wx + maxx;
281 			else {
282 				if (*wlp->firstchp - swin->ch_off > 0) {
283 					wx += *wlp->firstchp - swin->ch_off;
284 					x_off += *wlp->firstchp - swin->ch_off;
285 				}
286 				mx = maxx;
287 				if (mx > *wlp->lastchp - swin->ch_off + 1)
288 					mx = *dwlp->lastchp - dwin->ch_off + 1;
289 				if (x_off + (mx - wx) > screen->__virtscr->maxx)
290 					mx -= (x_off + maxx) -
291 					    screen->__virtscr->maxx;
292 			}
293 
294 			/* Copy line from "win" to "__virtscr". */
295 			while (wx < mx) {
296 #ifdef DEBUG
297 				__CTRACE(__CTRACE_REFRESH,
298 				    "_wnoutrefresh: copy from %d, "
299 				    "%d to %d, %d: %s, 0x%x",
300 				    wy, wx, y_off, x_off,
301 				    unctrl(wlp->line[wx].ch),
302 				    wlp->line[wx].attr);
303 #endif
304 				/* Copy character */
305 				vlp->line[x_off].ch = wlp->line[wx].ch;
306 				/* Copy attributes  */
307 				vlp->line[x_off].attr = wlp->line[wx].attr;
308 				/* Check for nca conflict with colour */
309 				if ((vlp->line[x_off].attr & __COLOR) &&
310 				    (vlp->line[x_off].attr & screen->nca))
311 					vlp->line[x_off].attr &= ~__COLOR;
312 				if (win->flags & __ISDERWIN) {
313 					dwlp->line[dx_off].ch =
314 						wlp->line[wx].ch;
315 					dwlp->line[dx_off].attr =
316 						wlp->line[wx].attr;
317 				}
318 
319 #ifdef HAVE_WCHAR
320 				if (wlp->line[wx].ch
321 				    == (wchar_t)btowc((int) win->bch)) {
322 					vlp->line[x_off].ch = win->bch;
323 					SET_WCOL(vlp->line[x_off], 1);
324 					if (_cursesi_copy_nsp(win->bnsp,
325 							      &vlp->line[x_off])
326 					    == ERR)
327 						return ERR;
328 					if (win->flags & __ISDERWIN) {
329 						dwlp->line[dx_off].ch =
330 							win->bch;
331 						SET_WCOL(dwlp->line[dx_off], 1);
332 						if (_cursesi_copy_nsp(win->bnsp,
333 						     &dwlp->line[dx_off])
334 						    == ERR)
335 							return ERR;
336 					}
337 				}
338 #endif /* HAVE_WCHAR */
339 #ifdef DEBUG
340 				__CTRACE(__CTRACE_REFRESH, " = %s, 0x%x\n",
341 				    unctrl(vlp->line[x_off].ch),
342 				    vlp->line[x_off].attr);
343 #endif
344 				wx++;
345 				x_off++;
346 				dx_off++;
347 			}
348 
349 			/* Set flags on "__virtscr" and unset on "win". */
350 			if (wlp->flags & __ISPASTEOL)
351 				vlp->flags |= __ISPASTEOL;
352 			else
353 				vlp->flags &= ~__ISPASTEOL;
354 			if (wlp->flags & __ISDIRTY)
355 				vlp->flags |= __ISDIRTY;
356 			if (wlp->flags & __ISFORCED)
357 				vlp->flags |= __ISFORCED;
358 
359 #ifdef DEBUG
360 			__CTRACE(__CTRACE_REFRESH,
361 			    "win: firstch = %d, lastch = %d\n",
362 			    *wlp->firstchp, *wlp->lastchp);
363 			if (win->flags & __ISDERWIN) {
364 				__CTRACE(__CTRACE_REFRESH,
365 				    "derwin: fistch = %d, lastch = %d\n",
366 				    *dwlp->firstchp, *dwlp->lastchp);
367 			}
368 #endif
369 			/* Set change pointers on "__virtscr". */
370 			if (*vlp->firstchp >
371 				*wlp->firstchp + wbegx - win->ch_off)
372 					*vlp->firstchp =
373 					    *wlp->firstchp + wbegx - win->ch_off;
374 			if (*vlp->lastchp <
375 				*wlp->lastchp + wbegx - win->ch_off)
376 					*vlp->lastchp =
377 					    *wlp->lastchp + wbegx - win->ch_off;
378 
379 			if (win->flags & __ISDERWIN) {
380 				if (*vlp->firstchp >
381 				    *dwlp->firstchp + wbegx - dwin->ch_off)
382 				{
383 					*vlp->firstchp =
384 					    *dwlp->firstchp + wbegx
385 						- dwin->ch_off;
386 					vlp->flags |= __ISDIRTY;
387 				}
388 
389 				if (*vlp->lastchp <
390 				    *dwlp->lastchp + wbegx - dwin->ch_off)
391 				{
392 					*vlp->lastchp = *dwlp->lastchp
393 					    + wbegx - dwin->ch_off;
394 					vlp->flags |= __ISDIRTY;
395 				}
396 			}
397 
398 #ifdef DEBUG
399 			__CTRACE(__CTRACE_REFRESH,
400 			    "__virtscr: firstch = %d, lastch = %d\n",
401 			    *vlp->firstchp, *vlp->lastchp);
402 #endif
403 			/*
404 			 * Unset change pointers only if a window and we
405 			 * are not forcing a redraw. A pad can be displayed
406 			 * again without any of the contents changing.
407 			 */
408 			if ((!(win->flags & __ISPAD)) ||
409 			    ((wlp->flags & __ISFORCED) == __ISFORCED))
410 			{
411 				/* Set change pointers on "win". */
412 				if (*wlp->firstchp >= win->ch_off)
413 					*wlp->firstchp = maxx + win->ch_off;
414 				if (*wlp->lastchp < maxx + win->ch_off)
415 					*wlp->lastchp = win->ch_off;
416 				if ((*wlp->lastchp < *wlp->firstchp) ||
417 				    (*wlp->firstchp >= maxx + win->ch_off) ||
418 				    (*wlp->lastchp <= win->ch_off)) {
419 #ifdef DEBUG
420 					__CTRACE(__CTRACE_REFRESH,
421 					    "_wnoutrefresh: "
422 					    "line %d notdirty\n", wy);
423 #endif
424 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
425 				}
426 			}
427 		}
428 	}
429 	return OK;
430 }
431 
432 /*
433  * wrefresh --
434  *	Make the current screen look like "win" over the area covered by
435  *	win.
436  */
437 int
438 wrefresh(WINDOW *win)
439 {
440 	int retval;
441 	int pbegx, pbegy;
442 
443 #ifdef DEBUG
444 	__CTRACE(__CTRACE_REFRESH, "wrefresh: win %p\n", win);
445 #endif
446 
447 	_cursesi_screen->curwin = (win == _cursesi_screen->curscr);
448 	if (!_cursesi_screen->curwin) {
449 		pbegx = pbegy = 0;
450 		if ((win->flags & __ISDERWIN) == __ISDERWIN) {
451 			pbegx = win->derx;
452 			pbegy = win->dery;
453 #ifdef DEBUG
454 	__CTRACE(__CTRACE_REFRESH, "wrefresh: derwin, begy = %d, begx = %x\n",
455 		pbegy, pbegx);
456 #endif
457 		}
458 		retval = _wnoutrefresh(win, pbegy, pbegx, win->begy, win->begx,
459 		    win->maxy, win->maxx);
460 	} else
461 		retval = OK;
462 	if (retval == OK) {
463 		retval = doupdate();
464 		if (!(win->flags & __LEAVEOK)) {
465 			win->cury = max(0, curscr->cury - win->begy);
466 			win->curx = max(0, curscr->curx - win->begx);
467 		}
468 	}
469 	_cursesi_screen->curwin = 0;
470 	return retval;
471 }
472 
473  /*
474  * prefresh --
475  *	Make the current screen look like "pad" over the area coverd by
476  *	the specified area of pad.
477  */
478 int
479 prefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
480 	int smaxy, int smaxx)
481 {
482 	int retval;
483 
484 #ifdef DEBUG
485 	__CTRACE(__CTRACE_REFRESH, "prefresh: pad %p, flags 0x%08x\n",
486 	    pad, pad->flags);
487 #endif
488 	/* Retain values in case pechochar() is called. */
489 	pad->pbegy = pbegy;
490 	pad->pbegx = pbegx;
491 	pad->sbegy = sbegy;
492 	pad->sbegx = sbegx;
493 	pad->smaxy = smaxy;
494 	pad->smaxx = smaxx;
495 
496 	/* Use pnoutrefresh() to avoid duplicating code here */
497 	retval = pnoutrefresh(pad, pbegy, pbegx, sbegy, sbegx, smaxy, smaxx);
498 	if (retval == OK) {
499 		retval = doupdate();
500 		if (!(pad->flags & __LEAVEOK)) {
501 			pad->cury = max(0, curscr->cury - pad->begy);
502 			pad->curx = max(0, curscr->curx - pad->begx);
503 		}
504 	}
505 	return retval;
506 }
507 
508 /*
509  * doupdate --
510  *	Make the current screen look like the virtual window "__virtscr".
511  */
512 int
513 doupdate(void)
514 {
515 	WINDOW	*win;
516 	__LINE	*wlp, *vlp;
517 	short	 wy;
518 	int	 dnum, was_cleared, changed;
519 #ifdef HAVE_WCHAR
520 	__LDATA *lp;
521 	nschar_t *np;
522 	int x;
523 #endif /* HAVE_WCHAR */
524 
525 	/* Check if we need to restart ... */
526 	if (_cursesi_screen->endwin)
527 		__restartwin();
528 
529 	if (_cursesi_screen->curwin)
530 		win = curscr;
531 	else
532 		win = _cursesi_screen->__virtscr;
533 
534 	/* Initialize loop parameters. */
535 	_cursesi_screen->ly = curscr->cury;
536 	_cursesi_screen->lx = curscr->curx;
537 	wy = 0;
538 
539 	if (!_cursesi_screen->curwin) {
540 		for (wy = 0; wy < win->maxy; wy++) {
541 			wlp = win->alines[wy];
542 			if (wlp->flags & __ISDIRTY) {
543 #ifndef HAVE_WCHAR
544 				wlp->hash = __hash(wlp->line,
545 				    (size_t)(win->maxx * __LDATASIZE));
546 #else
547 				wlp->hash = 0;
548 				for ( x = 0; x < win->maxx; x++ ) {
549 					lp = &wlp->line[ x ];
550 					wlp->hash = __hash_more( &lp->ch,
551 						sizeof(wchar_t), wlp->hash );
552 					wlp->hash = __hash_more( &lp->attr,
553 						sizeof(attr_t), wlp->hash );
554 					np = lp->nsp;
555 					if (np) {
556 						while (np) {
557 							wlp->hash
558 							    = __hash_more(
559 								&np->ch,
560 								sizeof(wchar_t),
561 								wlp->hash);
562 							np = np->next;
563 						}
564 					}
565 				}
566 #endif /* HAVE_WCHAR */
567 			}
568 		}
569 	}
570 
571 	was_cleared = 0;
572 	if ((win->flags & __CLEAROK) || (curscr->flags & __CLEAROK) ||
573 	    _cursesi_screen->curwin)
574 	{
575 		if (curscr->wattr & __COLOR)
576 			__unsetattr(0);
577 		tputs(clear_screen, 0, __cputchar);
578 		_cursesi_screen->ly = 0;
579 		_cursesi_screen->lx = 0;
580 		if (!_cursesi_screen->curwin) {
581 			curscr->flags &= ~__CLEAROK;
582 			curscr->cury = 0;
583 			curscr->curx = 0;
584 			werase(curscr);
585 		}
586 		__touchwin(win);
587 		win->flags &= ~__CLEAROK;
588 		/* note we cleared for later */
589 		was_cleared = 1;
590 	}
591 	if (!cursor_address) {
592 		if (win->curx != 0)
593 			__cputchar('\n');
594 		if (!_cursesi_screen->curwin)
595 			werase(curscr);
596 	}
597 #ifdef DEBUG
598 	__CTRACE(__CTRACE_REFRESH, "doupdate: (%p): curwin = %d\n", win,
599 	    _cursesi_screen->curwin);
600 	__CTRACE(__CTRACE_REFRESH, "doupdate: \tfirstch\tlastch\n");
601 #endif
602 
603 	if (!_cursesi_screen->curwin) {
604 		/*
605 		 * Invoke quickch() only if more than a quarter of the lines
606 		 * in the window are dirty.
607 		 */
608 		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
609 			if (win->alines[wy]->flags & __ISDIRTY)
610 				dnum++;
611 		if (!__noqch && dnum > (int) win->maxy / 4)
612 			quickch();
613 	}
614 
615 #ifdef DEBUG
616 	{
617 		int	i, j;
618 
619 		__CTRACE(__CTRACE_REFRESH,
620 		    "#####################################\n");
621 		__CTRACE(__CTRACE_REFRESH,
622 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
623 		    stdscr, curscr, _cursesi_screen->__virtscr);
624 		for (i = 0; i < curscr->maxy; i++) {
625 			__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
626 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
627 			    curscr->alines[i]->hash);
628 			for (j = 0; j < curscr->maxx; j++)
629 				__CTRACE(__CTRACE_REFRESH, "%c",
630 				    curscr->alines[i]->line[j].ch);
631 			__CTRACE(__CTRACE_REFRESH, "\n");
632 			__CTRACE(__CTRACE_REFRESH, " attr:");
633 			for (j = 0; j < curscr->maxx; j++)
634 				__CTRACE(__CTRACE_REFRESH, " %x",
635 				    curscr->alines[i]->line[j].attr);
636 			__CTRACE(__CTRACE_REFRESH, "\n");
637 			__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
638 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
639 			    win->alines[i]->hash);
640 			__CTRACE(__CTRACE_REFRESH, " 0x%x ",
641 			    win->alines[i]->flags);
642 			for (j = 0; j < win->maxx; j++)
643 				__CTRACE(__CTRACE_REFRESH, "%c",
644 				    win->alines[i]->line[j].ch);
645 			__CTRACE(__CTRACE_REFRESH, "\n");
646 			__CTRACE(__CTRACE_REFRESH, " attr:");
647 			for (j = 0; j < win->maxx; j++)
648 				__CTRACE(__CTRACE_REFRESH, " %x",
649 				    win->alines[i]->line[j].attr);
650 			__CTRACE(__CTRACE_REFRESH, "\n");
651 #ifdef HAVE_WCHAR
652 			__CTRACE(__CTRACE_REFRESH, " nsp:");
653 			for (j = 0; j < curscr->maxx; j++)
654 				__CTRACE(__CTRACE_REFRESH, " %p",
655 				    win->alines[i]->line[j].nsp);
656 			__CTRACE(__CTRACE_REFRESH, "\n");
657 			__CTRACE(__CTRACE_REFRESH, " bnsp:");
658 			for (j = 0; j < curscr->maxx; j++)
659 				__CTRACE(__CTRACE_REFRESH, " %p",
660 				    win->bnsp);
661 			__CTRACE(__CTRACE_REFRESH, "\n");
662 #endif /* HAVE_WCHAR */
663 		}
664 	}
665 #endif /* DEBUG */
666 
667 	changed = 0;
668 	for (wy = 0; wy < win->maxy; wy++) {
669 		wlp = win->alines[wy];
670 		vlp = _cursesi_screen->__virtscr->alines[win->begy + wy];
671 /* XXX: remove this debug */
672 #ifdef DEBUG
673 		__CTRACE(__CTRACE_REFRESH,
674 		    "doupdate: wy %d\tf: %d\tl:%d\tflags %x\n",
675 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
676 #endif /* DEBUG */
677 		if (!_cursesi_screen->curwin)
678 			curscr->alines[wy]->hash = wlp->hash;
679 		if (wlp->flags & __ISDIRTY || wlp->flags & __ISFORCED) {
680 #ifdef DEBUG
681 			__CTRACE(__CTRACE_REFRESH,
682 			    "doupdate: [ISDIRTY]wy:%d\tf:%d\tl:%d\n", wy,
683 			    *wlp->firstchp, *wlp->lastchp);
684 #endif /* DEBUG */
685 			/*
686 			 * We have just cleared so don't force an update
687 			 * otherwise we spray neeedless blanks to a cleared
688 			 * screen.
689 			 */
690 			if (was_cleared == 1)
691 				win->alines[wy]->flags &= ~__ISFORCED;
692 
693 			if (makech(wy) == ERR)
694 				return ERR;
695 			else {
696 				if (*wlp->firstchp >= 0)
697 					*wlp->firstchp = win->maxx;
698 				if (*wlp->lastchp < win->maxx)
699 					*wlp->lastchp = win->ch_off;
700 				if (*wlp->lastchp < *wlp->firstchp) {
701 #ifdef DEBUG
702 					__CTRACE(__CTRACE_REFRESH,
703 					    "doupdate: line %d notdirty\n", wy);
704 #endif /* DEBUG */
705 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
706 				}
707 
708 				/* Check if we have input after
709 				 * changing N lines. */
710 				if (_cursesi_screen->checkfd != -1 &&
711 				    ++changed == CHECK_INTERVAL)
712 				{
713 					struct pollfd fds[1];
714 
715 					/* If we have input, abort. */
716 					fds[0].fd = _cursesi_screen->checkfd;
717 					fds[0].events = POLLIN;
718 					if (poll(fds, 1, 0) > 0)
719 						goto cleanup;
720 					changed = 0;
721 				}
722 			}
723 		}
724 
725 		/*
726 		 * virtscr is now synced for the line, unset the change
727 		 * pointers.
728 		 */
729 		if (*vlp->firstchp >= 0)
730 			*vlp->firstchp = _cursesi_screen->__virtscr->maxx;
731 		if (*vlp->lastchp <= _cursesi_screen->__virtscr->maxx)
732 			*vlp->lastchp = 0;
733 
734 #ifdef DEBUG
735 		__CTRACE(__CTRACE_REFRESH, "\t%d\t%d\n",
736 		    *wlp->firstchp, *wlp->lastchp);
737 #endif /* DEBUG */
738 	}
739 
740 #ifdef DEBUG
741 	__CTRACE(__CTRACE_REFRESH, "doupdate: ly=%d, lx=%d\n",
742 	    _cursesi_screen->ly, _cursesi_screen->lx);
743 #endif /* DEBUG */
744 
745 	if (_cursesi_screen->curwin)
746 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
747 			win->cury, win->curx);
748 	else {
749 		if (win->flags & __LEAVEOK) {
750 			curscr->cury = _cursesi_screen->ly;
751 			curscr->curx = _cursesi_screen->lx;
752 		} else {
753 			domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
754 				win->cury, win->curx);
755 			curscr->cury = win->cury;
756 			curscr->curx = win->curx;
757 		}
758 	}
759 
760 cleanup:
761 	/* Don't leave the screen with attributes set. */
762 	__unsetattr(0);
763 #ifdef DEBUG
764 #ifdef HAVE_WCHAR
765 	{
766 		int	i, j;
767 
768 		__CTRACE(__CTRACE_REFRESH,
769 		    "***********after*****************\n");
770 		__CTRACE(__CTRACE_REFRESH,
771 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
772 		    stdscr, curscr, _cursesi_screen->__virtscr);
773 		for (i = 0; i < curscr->maxy; i++) {
774 			for (j = 0; j < curscr->maxx; j++)
775 				__CTRACE(__CTRACE_REFRESH,
776 				    "[%d,%d](%x,%x,%p)-(%x,%x,%p)\n",
777 				    i, j,
778 				    curscr->alines[i]->line[j].ch,
779 				    curscr->alines[i]->line[j].attr,
780 				    curscr->alines[i]->line[j].nsp,
781 				    _cursesi_screen->__virtscr->alines[i]->line[j].ch,
782 				    _cursesi_screen->__virtscr->alines[i]->line[j].attr,
783 				    _cursesi_screen->__virtscr->alines[i]->line[j].nsp);
784 		}
785 	}
786 #endif /* HAVE_WCHAR */
787 #endif /* DEBUG */
788 	return fflush(_cursesi_screen->outfd) == EOF ? ERR : OK;
789 }
790 
791 static void
792 putattr(__LDATA *nsp)
793 {
794 	attr_t	off, on;
795 
796 #ifdef DEBUG
797 	__CTRACE(__CTRACE_REFRESH,
798 	    "makech: have attr %08x, need attr %08x\n",
799 	    curscr->wattr
800 #ifndef HAVE_WCHAR
801 	    & __ATTRIBUTES
802 #else
803 	    & WA_ATTRIBUTES
804 #endif
805 	    ,  nsp->attr
806 #ifndef HAVE_WCHAR
807 	    & __ATTRIBUTES
808 #else
809 	    & WA_ATTRIBUTES
810 #endif
811 	    );
812 #endif
813 
814 	off = (~nsp->attr & curscr->wattr)
815 #ifndef HAVE_WCHAR
816 	    & __ATTRIBUTES
817 #else
818 	    & WA_ATTRIBUTES
819 #endif
820 	    ;
821 
822 	/*
823 	 * Unset attributes as appropriate.  Unset first
824 	 * so that the relevant attributes can be reset
825 	 * (because 'me' unsets 'mb', 'md', 'mh', 'mk',
826 	 * 'mp' and 'mr').  Check to see if we also turn off
827 	 * standout, attributes and colour.
828 	 */
829 	if (off & __TERMATTR && exit_attribute_mode != NULL) {
830 		tputs(exit_attribute_mode, 0, __cputchar);
831 		curscr->wattr &= __mask_me;
832 		off &= __mask_me;
833 	}
834 
835 	/*
836 	 * Exit underscore mode if appropriate.
837 	 * Check to see if we also turn off standout,
838 	 * attributes and colour.
839 	 */
840 	if (off & __UNDERSCORE && exit_underline_mode != NULL) {
841 		tputs(exit_underline_mode, 0, __cputchar);
842 		curscr->wattr &= __mask_ue;
843 		off &= __mask_ue;
844 	}
845 
846 	/*
847 	 * Exit standout mode as appropriate.
848 	 * Check to see if we also turn off underscore,
849 	 * attributes and colour.
850 	 * XXX
851 	 * Should use uc if so/se not available.
852 	 */
853 	if (off & __STANDOUT && exit_standout_mode != NULL) {
854 		tputs(exit_standout_mode, 0, __cputchar);
855 		curscr->wattr &= __mask_se;
856 		off &= __mask_se;
857 	}
858 
859 	if (off & __ALTCHARSET && exit_alt_charset_mode != NULL) {
860 		tputs(exit_alt_charset_mode, 0, __cputchar);
861 		curscr->wattr &= ~__ALTCHARSET;
862 	}
863 
864 	/* Set/change colour as appropriate. */
865 	if (__using_color)
866 		__set_color(curscr, nsp->attr & __COLOR);
867 
868 	on = (nsp->attr & ~curscr->wattr)
869 #ifndef HAVE_WCHAR
870 	    & __ATTRIBUTES
871 #else
872 	    & WA_ATTRIBUTES
873 #endif
874 	    ;
875 
876 	/*
877 	 * Enter standout mode if appropriate.
878 	 */
879 	if (on & __STANDOUT &&
880 	    enter_standout_mode != NULL &&
881 	    exit_standout_mode != NULL)
882 	{
883 		tputs(enter_standout_mode, 0, __cputchar);
884 		curscr->wattr |= __STANDOUT;
885 	}
886 
887 	/*
888 	 * Enter underscore mode if appropriate.
889 	 * XXX
890 	 * Should use uc if us/ue not available.
891 	 */
892 	if (on & __UNDERSCORE &&
893 	    enter_underline_mode != NULL &&
894 	    exit_underline_mode != NULL)
895 	{
896 		tputs(enter_underline_mode, 0, __cputchar);
897 		curscr->wattr |= __UNDERSCORE;
898 	}
899 
900 	/*
901 	 * Set other attributes as appropriate.
902 	 */
903 	if (exit_attribute_mode != NULL) {
904 		if (on & __BLINK && enter_blink_mode != NULL)
905 		{
906 			tputs(enter_blink_mode, 0, __cputchar);
907 			curscr->wattr |= __BLINK;
908 		}
909 		if (on & __BOLD && enter_bold_mode != NULL)
910 		{
911 			tputs(enter_bold_mode, 0, __cputchar);
912 			curscr->wattr |= __BOLD;
913 		}
914 		if (on & __DIM && enter_dim_mode != NULL)
915 		{
916 			tputs(enter_dim_mode, 0, __cputchar);
917 			curscr->wattr |= __DIM;
918 		}
919 		if (on & __BLANK && enter_secure_mode != NULL)
920 		{
921 			tputs(enter_secure_mode, 0, __cputchar);
922 			curscr->wattr |= __BLANK;
923 		}
924 		if (on & __PROTECT && enter_protected_mode != NULL)
925 		{
926 			tputs(enter_protected_mode, 0, __cputchar);
927 			curscr->wattr |= __PROTECT;
928 		}
929 		if (on & __REVERSE && enter_reverse_mode != NULL)
930 		{
931 			tputs(enter_reverse_mode, 0, __cputchar);
932 			curscr->wattr |= __REVERSE;
933 		}
934 #ifdef HAVE_WCHAR
935 		if (on & WA_TOP && enter_top_hl_mode != NULL)
936 		{
937 			tputs(enter_top_hl_mode, 0, __cputchar);
938 			curscr->wattr |= WA_TOP;
939 		}
940 		if (on & WA_LOW && enter_low_hl_mode != NULL)
941 		{
942 			tputs(enter_low_hl_mode, 0, __cputchar);
943 			curscr->wattr |= WA_LOW;
944 		}
945 		if (on & WA_LEFT && enter_left_hl_mode != NULL)
946 		{
947 			tputs(enter_left_hl_mode, 0, __cputchar);
948 			curscr->wattr |= WA_LEFT;
949 		}
950 		if (on & WA_RIGHT && enter_right_hl_mode != NULL)
951 		{
952 			tputs(enter_right_hl_mode, 0, __cputchar);
953 			curscr->wattr |= WA_RIGHT;
954 		}
955 		if (on & WA_HORIZONTAL && enter_horizontal_hl_mode != NULL)
956 		{
957 			tputs(enter_horizontal_hl_mode, 0, __cputchar);
958 			curscr->wattr |= WA_HORIZONTAL;
959 		}
960 		if (on & WA_VERTICAL && enter_vertical_hl_mode != NULL)
961 		{
962 			tputs(enter_vertical_hl_mode, 0, __cputchar);
963 			curscr->wattr |= WA_VERTICAL;
964 		}
965 #endif /* HAVE_WCHAR */
966 	}
967 
968 	/* Enter/exit altcharset mode as appropriate. */
969 	if (on & __ALTCHARSET && enter_alt_charset_mode != NULL &&
970 	    exit_alt_charset_mode != NULL) {
971 		tputs(enter_alt_charset_mode, 0, __cputchar);
972 		curscr->wattr |= __ALTCHARSET;
973 	}
974 }
975 
976 static void
977 putattr_out(__LDATA *nsp)
978 {
979 
980 	if (underline_char &&
981 	    ((nsp->attr & __STANDOUT) || (nsp->attr & __UNDERSCORE)))
982 	{
983 		__cputchar('\b');
984 		tputs(underline_char, 0, __cputchar);
985 	}
986 }
987 
988 static int
989 putch(__LDATA *nsp, __LDATA *csp, int wy, int wx)
990 {
991 
992 	if (csp != NULL)
993 		putattr(nsp);
994 
995 	if (!_cursesi_screen->curwin && csp) {
996 		csp->attr = nsp->attr;
997 		csp->ch = nsp->ch;
998 #ifdef HAVE_WCHAR
999 		if (_cursesi_copy_nsp(nsp->nsp, csp) == ERR)
1000 			return ERR;
1001 #endif /* HAVE_WCHAR */
1002 	}
1003 
1004 #ifndef HAVE_WCHAR
1005 	__cputchar((int)nsp->ch);
1006 #else
1007 	if (WCOL(*nsp) <= 0)
1008 		goto out;
1009 	__cputwchar((int)nsp->ch);
1010 #ifdef DEBUG
1011 	__CTRACE(__CTRACE_REFRESH,
1012 	    "makech: (%d,%d)putwchar(0x%x)\n", wy, wx - 1, nsp->ch);
1013 #endif /* DEBUG */
1014 
1015 	/* Output non-spacing characters for the cell. */
1016 	__cursesi_putnsp(nsp->nsp, wy, wx);
1017 out:
1018 #endif /* HAVE_WCHAR */
1019 
1020 	if (csp != NULL)
1021 		putattr_out(nsp);
1022 	return OK;
1023 }
1024 
1025 static int
1026 putchbr(__LDATA *nsp, __LDATA *csp, __LDATA *psp, int wy, int wx)
1027 {
1028 	int error, cw, pcw;
1029 
1030 	/* Can safely print to bottom right corner. */
1031 	if (!auto_right_margin)
1032 		return putch(nsp, csp, wy, wx);
1033 
1034 	/* Disable auto margins temporarily. */
1035 	if (enter_am_mode && exit_am_mode) {
1036 		tputs(exit_am_mode, 0, __cputchar);
1037 		error = putch(nsp, csp, wy, wx);
1038 		tputs(enter_am_mode, 0, __cputchar);
1039 		return error;
1040 	}
1041 
1042 	/* We need to insert characters.
1043 	 * To do this, work out their widths.
1044 	 * XXX This does not work when the bottom right corner is an ACS. */
1045 #ifdef HAVE_WCHAR
1046 	cw = wcwidth(nsp->ch);
1047 	pcw = psp == NULL ? 0 : wcwidth(psp->ch);
1048 	if (pcw < 1)
1049 		return ERR; /* Nothing to insert */
1050 
1051 	/* When wide characters we need something other than
1052 	 * insert_character. */
1053 	if (pcw > 1 &&
1054 	    !(parm_ich != NULL ||
1055 	    (enter_insert_mode != NULL && exit_insert_mode != NULL)))
1056 		return ERR;
1057 #else
1058 	cw = pcw = 1;
1059 #endif /* HAVE_WCHAR */
1060 
1061 	/* Write the corner character at wx - pcw. */
1062 	__mvcur(wy, wx, wy, wx - pcw, 1);
1063 	if (putch(nsp, csp, wy, wx) == ERR)
1064 		return ERR;
1065 
1066 	/* Move cursor back. */
1067 	__mvcur(wy, wx - pcw + cw, wy, wx - cw, 1);
1068 
1069 	putattr(psp);
1070 
1071 	/* Enter insert mode. */
1072 	if (pcw == 1 && insert_character != NULL)
1073 		tputs(insert_character, 0, __cputchar);
1074 	else if (parm_ich != NULL)
1075 		tputs(tiparm(parm_ich, (long)pcw), 0, __cputchar);
1076 	else if (enter_insert_mode != NULL && exit_insert_mode != NULL)
1077 		tputs(enter_insert_mode, 0, __cputchar);
1078 	else
1079 		return ERR;
1080 
1081 	/* Insert the old character back. */
1082 	error = putch(psp, NULL, wy, wx - pcw);
1083 
1084 	/* Exit insert mode. */
1085 	if (insert_character != NULL || parm_ich != NULL)
1086 		;
1087 	else if (enter_insert_mode != NULL && exit_insert_mode != NULL)
1088 		tputs(exit_insert_mode, 0, __cputchar);
1089 
1090 	putattr_out(psp);
1091 
1092 	return error;
1093 }
1094 
1095 /*
1096  * makech --
1097  *	Make a change on the screen.
1098  */
1099 static int
1100 makech(int wy)
1101 {
1102 	WINDOW	*win;
1103 	static __LDATA blank;
1104 	__LDATA *nsp, *csp, *cp, *cep, *fsp;
1105 	__LINE *wlp;
1106 	size_t	clsp, nlsp;	/* Last space in lines. */
1107 	int	lch, wx, chw;
1108 	const char	*ce;
1109 	attr_t	lspc;		/* Last space colour */
1110 
1111 #ifdef __GNUC__
1112 	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
1113 #endif
1114 	if (_cursesi_screen->curwin)
1115 		win = curscr;
1116 	else
1117 		win = __virtscr;
1118 #ifdef HAVE_WCHAR
1119 	blank.ch = (wchar_t)btowc((int) win->bch);
1120 	blank.attr = 0;
1121 	if (_cursesi_copy_nsp(win->bnsp, &blank) == ERR)
1122 		return ERR;
1123 	SET_WCOL(blank, 1);
1124 #endif /* HAVE_WCHAR */
1125 #ifdef DEBUG
1126 #if HAVE_WCHAR
1127 	{
1128 		int x;
1129 		__LDATA *lp, *vlp;
1130 
1131 		__CTRACE(__CTRACE_REFRESH,
1132 		    "[makech-before]wy=%d,curscr(%p)-__virtscr(%p)\n",
1133 		    wy, curscr, __virtscr);
1134 		for (x = 0; x < curscr->maxx; x++) {
1135 			lp = &curscr->alines[wy]->line[x];
1136 			vlp = &__virtscr->alines[wy]->line[x];
1137 			__CTRACE(__CTRACE_REFRESH,
1138 			    "[%d,%d](%x,%x,%x,%x,%p)-"
1139 			    "(%x,%x,%x,%x,%p)\n",
1140 			    wy, x, lp->ch, lp->attr,
1141 			    win->bch, win->battr, lp->nsp,
1142 			    vlp->ch, vlp->attr,
1143 			    win->bch, win->battr, vlp->nsp);
1144 		}
1145 	}
1146 #endif /* HAVE_WCHAR */
1147 #endif /* DEBUG */
1148 	/* Is the cursor still on the end of the last line? */
1149 	if (wy > 0 && curscr->alines[wy - 1]->flags & __ISPASTEOL) {
1150 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
1151 			_cursesi_screen->ly + 1, 0);
1152 		_cursesi_screen->ly++;
1153 		_cursesi_screen->lx = 0;
1154 	}
1155 	wlp = win->alines[wy];
1156 	wx = *win->alines[wy]->firstchp;
1157 	if (wx < 0)
1158 		wx = 0;
1159 	else
1160 		if (wx >= win->maxx)
1161 			return (OK);
1162 	lch = *win->alines[wy]->lastchp;
1163 	if (lch < 0)
1164 		return OK;
1165 	else
1166 		if (lch >= (int) win->maxx)
1167 			lch = win->maxx - 1;
1168 
1169 	if (_cursesi_screen->curwin) {
1170 		csp = &blank;
1171 #ifdef DEBUG
1172 		__CTRACE(__CTRACE_REFRESH, "makech: csp is blank\n");
1173 #endif /* DEBUG */
1174 	} else {
1175 		csp = &curscr->alines[wy]->line[wx];
1176 #ifdef DEBUG
1177 		__CTRACE(__CTRACE_REFRESH,
1178 		    "makech: csp is on curscr:(%d,%d)\n", wy, wx);
1179 #endif /* DEBUG */
1180 	}
1181 
1182 	nsp = fsp = &win->alines[wy]->line[wx];
1183 #ifdef DEBUG
1184 	if (_cursesi_screen->curwin)
1185 		__CTRACE(__CTRACE_REFRESH,
1186 		    "makech: nsp is at curscr:(%d,%d)\n", wy, wx);
1187 	else
1188 		__CTRACE(__CTRACE_REFRESH,
1189 		    "makech: nsp is at __virtscr:(%d,%d)\n", wy, wx);
1190 #endif /* DEBUG */
1191 	if (clr_eol && !_cursesi_screen->curwin) {
1192 		cp = &win->alines[wy]->line[win->maxx - 1];
1193 		lspc = cp->attr & __COLOR;
1194 #ifndef HAVE_WCHAR
1195 		while (cp->ch == ' ' && cp->attr == lspc) /* XXX */
1196 			if (cp-- <= win->alines[wy]->line)
1197 				break;
1198 #else
1199 		while (cp->ch == ( wchar_t )btowc(( int )' ' )
1200 				&& ( cp->attr & WA_ATTRIBUTES ) == lspc)
1201 			if (cp-- <= win->alines[wy]->line)
1202 				break;
1203 #endif /* HAVE_WCHAR */
1204 		if (win->alines[wy]->line > cp)
1205 			nlsp = 0;
1206 		else
1207 			nlsp = cp - win->alines[wy]->line;
1208 	}
1209 	if (!_cursesi_screen->curwin)
1210 		ce = clr_eol;
1211 	else
1212 		ce = NULL;
1213 
1214 	while (wx <= lch) {
1215 #ifdef DEBUG
1216 #ifndef HAVE_WCHAR
1217 		__CTRACE(__CTRACE_REFRESH, "makech: wx=%d,lch=%d\n", wx, lch);
1218 #else
1219 		__CTRACE(__CTRACE_REFRESH, "makech: nsp=(%x,%x,%x,%x,%p)\n",
1220 			nsp->ch, nsp->attr, win->bch, win->battr, nsp->nsp);
1221 		__CTRACE(__CTRACE_REFRESH, "makech: csp=(%x,%x,%x,%x,%p)\n",
1222 			csp->ch, csp->attr, win->bch, win->battr, csp->nsp);
1223 #endif
1224 #endif /* DEBUG */
1225 		if (!(wlp->flags & __ISFORCED) &&
1226 #ifdef HAVE_WCHAR
1227 		    ((nsp->attr & __WCWIDTH) != __WCWIDTH) &&
1228 #endif
1229 		    celleq(nsp, csp))
1230 		{
1231 			if (wx <= lch) {
1232 				while (wx <= lch && celleq(nsp, csp)) {
1233 					nsp++;
1234 					if (!_cursesi_screen->curwin)
1235 						++csp;
1236 					++wx;
1237 				}
1238 				continue;
1239 			}
1240 			break;
1241 		}
1242 
1243 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
1244 
1245 #ifdef DEBUG
1246 		__CTRACE(__CTRACE_REFRESH, "makech: 1: wx = %d, ly= %d, "
1247 		    "lx = %d, newy = %d, newx = %d\n",
1248 		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
1249 #endif
1250 		_cursesi_screen->ly = wy;
1251 		_cursesi_screen->lx = wx;
1252 		while (wx <= lch &&
1253 		       ((wlp->flags & __ISFORCED) || !celleq(nsp, csp)))
1254 		{
1255 #ifndef HAVE_WCHAR
1256 			if (ce != NULL && wx >= nlsp
1257 			    && nsp->ch == ' ' && nsp->attr == lspc)
1258 #else
1259 			if (ce != NULL && wx >= nlsp
1260 			    && nsp->ch == (wchar_t)btowc((int)' ') /* XXX */
1261 			    && (nsp->attr & WA_ATTRIBUTES) == lspc)
1262 #endif
1263 			{
1264 				/* Check for clear to end-of-line. */
1265 				cep = &curscr->alines[wy]->line[win->maxx - 1];
1266 #ifndef HAVE_WCHAR
1267 				while (cep->ch == ' ' && cep->attr == lspc) /* XXX */
1268 #else
1269 				while (cep->ch == (wchar_t)btowc((int)' ')
1270 				       && (cep->attr & WA_ATTRIBUTES) == lspc)
1271 #endif /* HAVE_WCHAR */
1272 					if (cep-- <= csp)
1273 						break;
1274 				if (cep > (curscr->alines[wy]->line + win->begx * __LDATASIZE))
1275 					clsp = cep - curscr->alines[wy]->line -
1276 					win->begx * __LDATASIZE;
1277 				else
1278 					clsp = 0;
1279 #ifdef DEBUG
1280 				__CTRACE(__CTRACE_REFRESH,
1281 				    "makech: clsp = %zu, nlsp = %zu\n",
1282 				    clsp, nlsp);
1283 				__CTRACE(__CTRACE_REFRESH,
1284 				    "makech: line = %p, cep = %p, begx = %u\n",
1285 				    curscr->alines[wy]->line, cep, win->begx);
1286 #endif
1287 				if (((clsp - nlsp >= strlen(ce) &&
1288 				    clsp < win->maxx * __LDATASIZE) ||
1289 				    wy == win->maxy - 1) &&
1290 				    (!(lspc & __COLOR) ||
1291 				    ((lspc & __COLOR) && back_color_erase)))
1292 				{
1293 					__unsetattr(0);
1294 					if (__using_color &&
1295 					    ((lspc & __COLOR) !=
1296 					    (curscr->wattr & __COLOR)))
1297 						__set_color(curscr, lspc &
1298 						    __COLOR);
1299 					tputs(ce, 0, __cputchar);
1300 					_cursesi_screen->lx = wx + win->begx;
1301 					while (wx++ <= clsp) {
1302 						csp->attr = lspc;
1303 #ifndef HAVE_WCHAR
1304 						csp->ch = ' '; /* XXX */
1305 #else
1306 						csp->ch = (wchar_t)btowc((int)' ');
1307 						SET_WCOL( *csp, 1 );
1308 #endif /* HAVE_WCHAR */
1309 						csp++;
1310 					}
1311 					return OK;
1312 				}
1313 				ce = NULL;
1314 			}
1315 
1316 #ifdef HAVE_WCHAR
1317 			chw = wcwidth(nsp->ch);
1318 #else
1319 			chw = 1;
1320 #endif /* HAVE_WCHAR */
1321 			if (wx + chw >= win->maxx &&
1322 			    wy == win->maxy - 1 && !_cursesi_screen->curwin)
1323 			{
1324 				if (win->flags & __ENDLINE)
1325 					__unsetattr(1);
1326 				if (!(win->flags & __SCROLLWIN)) {
1327 					int e;
1328 
1329 					if (win->flags & __SCROLLOK)
1330 						e = putch(nsp, csp, wy, wx);
1331 					else
1332 						e = putchbr(nsp, csp,
1333 						    nsp == fsp ? NULL : nsp - 1,
1334 						    wy, wx);
1335 					if (e == ERR)
1336 						return ERR;
1337 				}
1338 				if (wx + chw < curscr->maxx) {
1339 					domvcur(win,
1340 					    _cursesi_screen->ly, wx,
1341 					    (int)(win->maxy - 1),
1342 					    (int)(win->maxx - 1));
1343 				}
1344 				_cursesi_screen->ly = win->maxy - 1;
1345 				_cursesi_screen->lx = win->maxx - 1;
1346 				return OK;
1347 			}
1348 			if (wx + chw < win->maxx || wy < win->maxy - 1 ||
1349 			    !(win->flags & __SCROLLWIN))
1350 			{
1351 				if (putch(nsp, csp, wy, wx) == ERR)
1352 					return ERR;
1353 				csp++;
1354 			} else {
1355 				putattr(nsp);
1356 				putattr_out(nsp);
1357 			}
1358 			wx += chw;
1359 			nsp++;
1360 #ifdef DEBUG
1361 			__CTRACE(__CTRACE_REFRESH,
1362 			    "makech: 2: wx = %d, lx = %d\n",
1363 			    wx, _cursesi_screen->lx);
1364 #endif
1365 		}
1366 		if (_cursesi_screen->lx == wx)	/* If no change. */
1367 			break;
1368 		_cursesi_screen->lx = wx;
1369 		if (_cursesi_screen->lx >= COLS && auto_right_margin)
1370 			_cursesi_screen->lx = COLS - 1;
1371 		else
1372 			if (wx >= win->maxx) {
1373 				domvcur(win,
1374 					_cursesi_screen->ly,
1375 					_cursesi_screen->lx,
1376 					_cursesi_screen->ly,
1377 					(int)(win->maxx - 1));
1378 				_cursesi_screen->lx = win->maxx - 1;
1379 			}
1380 #ifdef DEBUG
1381 		__CTRACE(__CTRACE_REFRESH, "makech: 3: wx = %d, lx = %d\n",
1382 		    wx, _cursesi_screen->lx);
1383 #endif
1384 	}
1385 #ifdef DEBUG
1386 #if HAVE_WCHAR
1387 	{
1388 		int x;
1389 		__LDATA *lp, *vlp;
1390 
1391 		__CTRACE(__CTRACE_REFRESH,
1392 		    "makech-after: curscr(%p)-__virtscr(%p)\n",
1393 		    curscr, __virtscr );
1394 		for (x = 0; x < curscr->maxx; x++) {
1395 			lp = &curscr->alines[wy]->line[x];
1396 			vlp = &__virtscr->alines[wy]->line[x];
1397 			__CTRACE(__CTRACE_REFRESH,
1398 			    "[%d,%d](%x,%x,%x,%x,%p)-"
1399 			    "(%x,%x,%x,%x,%p)\n",
1400 			    wy, x, lp->ch, lp->attr,
1401 			    win->bch, win->battr, lp->nsp,
1402 			    vlp->ch, vlp->attr,
1403 			    win->bch, win->battr, vlp->nsp);
1404 		}
1405 	}
1406 #endif /* HAVE_WCHAR */
1407 #endif /* DEBUG */
1408 
1409 	return OK;
1410 }
1411 
1412 /*
1413  * domvcur --
1414  *	Do a mvcur, leaving attributes if necessary.
1415  */
1416 static void
1417 domvcur(const WINDOW *win, int oy, int ox, int ny, int nx)
1418 {
1419 
1420 #ifdef DEBUG
1421 	__CTRACE(__CTRACE_REFRESH, "domvcur: (%x,%d)=>(%d,%d)\n",
1422 	    oy, ox, ny, nx );
1423 #endif /* DEBUG */
1424 
1425 	__unsetattr(1);
1426 
1427 	/* Don't move the cursor unless we need to. */
1428 	if (oy == ny && ox == nx) {
1429 		/* Check EOL. */
1430 		if (!(win->alines[oy]->flags & __ISPASTEOL))
1431 			return;
1432 	}
1433 
1434 	/* Clear EOL flags. */
1435 	win->alines[oy]->flags &= ~__ISPASTEOL;
1436 	win->alines[ny]->flags &= ~__ISPASTEOL;
1437 
1438 	__mvcur(oy, ox, ny, nx, 1);
1439 }
1440 
1441 /*
1442  * Quickch() attempts to detect a pattern in the change of the window
1443  * in order to optimize the change, e.g., scroll n lines as opposed to
1444  * repainting the screen line by line.
1445  */
1446 
1447 static __LDATA buf[128];
1448 static  unsigned int last_hash;
1449 static  size_t last_hash_len;
1450 #define BLANKSIZE (sizeof(buf) / sizeof(buf[0]))
1451 
1452 static void
1453 quickch(void)
1454 {
1455 #define THRESH		(int) __virtscr->maxy / 4
1456 
1457 	__LINE *clp, *tmp1, *tmp2;
1458 	int	bsize, curs, curw, starts, startw, i, j;
1459 	int	n, target, cur_period, bot, top, sc_region;
1460 	unsigned int	blank_hash;
1461 	attr_t	bcolor;
1462 
1463 #ifdef __GNUC__
1464 	curs = curw = starts = startw = 0;	/* XXX gcc -Wuninitialized */
1465 #endif
1466 	/*
1467 	 * Find how many lines from the top of the screen are unchanged.
1468 	 */
1469 	for (top = 0; top < __virtscr->maxy; top++) {
1470 		if (__virtscr->alines[top]->flags & __ISDIRTY &&
1471 		    (__virtscr->alines[top]->hash != curscr->alines[top]->hash ||
1472 		     !lineeq(__virtscr->alines[top]->line,
1473 			     curscr->alines[top]->line,
1474 			     (size_t) __virtscr->maxx)))
1475 			break;
1476 		else
1477 			__virtscr->alines[top]->flags &= ~__ISDIRTY;
1478 	}
1479 	/*
1480 	 * Find how many lines from bottom of screen are unchanged.
1481 	 */
1482 	for (bot = __virtscr->maxy - 1; bot >= 0; bot--) {
1483 		if (__virtscr->alines[bot]->flags & __ISDIRTY &&
1484 		    (__virtscr->alines[bot]->hash != curscr->alines[bot]->hash ||
1485 		     !lineeq(__virtscr->alines[bot]->line,
1486 			     curscr->alines[bot]->line,
1487 			     (size_t) __virtscr->maxx)))
1488 			break;
1489 		else
1490 			__virtscr->alines[bot]->flags &= ~__ISDIRTY;
1491 	}
1492 
1493 	/*
1494 	 * Work round an xterm bug where inserting lines causes all the
1495 	 * inserted lines to be covered with the background colour we
1496 	 * set on the first line (even if we unset it for subsequent
1497 	 * lines).
1498 	 */
1499 	bcolor = __virtscr->alines[min(top,
1500 	    __virtscr->maxy - 1)]->line[0].attr & __COLOR;
1501 	for (i = top + 1, j = 0; i < bot; i++) {
1502 		if ((__virtscr->alines[i]->line[0].attr & __COLOR) != bcolor) {
1503 			bcolor = __virtscr->alines[i]->line[__virtscr->maxx].
1504 			    attr & __COLOR;
1505 			j = i - top;
1506 		} else
1507 			break;
1508 	}
1509 	top += j;
1510 
1511 #ifdef NO_JERKINESS
1512 	/*
1513 	 * If we have a bottom unchanged region return.  Scrolling the
1514 	 * bottom region up and then back down causes a screen jitter.
1515 	 * This will increase the number of characters sent to the screen
1516 	 * but it looks better.
1517 	 */
1518 	if (bot < __virtscr->maxy - 1)
1519 		return;
1520 #endif				/* NO_JERKINESS */
1521 
1522 	/*
1523 	 * Search for the largest block of text not changed.
1524 	 * Invariants of the loop:
1525 	 * - Startw is the index of the beginning of the examined block in
1526 	 *   __virtscr.
1527 	 * - Starts is the index of the beginning of the examined block in
1528 	 *   curscr.
1529 	 * - Curw is the index of one past the end of the exmined block in
1530 	 *   __virtscr.
1531 	 * - Curs is the index of one past the end of the exmined block in
1532 	 *   curscr.
1533 	 * - bsize is the current size of the examined block.
1534 	*/
1535 
1536 	for (bsize = bot - top; bsize >= THRESH; bsize--) {
1537 		for (startw = top; startw <= bot - bsize; startw++)
1538 			for (starts = top; starts <= bot - bsize; starts++) {
1539 				for (curw = startw, curs = starts;
1540 				    curs < starts + bsize; curw++, curs++)
1541 					if (__virtscr->alines[curw]->hash !=
1542 					    curscr->alines[curs]->hash)
1543 						break;
1544 				if (curs != starts + bsize)
1545 					continue;
1546 				for (curw = startw, curs = starts;
1547 					curs < starts + bsize; curw++, curs++)
1548 					if (!lineeq(__virtscr->alines[curw]->line,
1549 						    curscr->alines[curs]->line,
1550 						    (size_t) __virtscr->maxx))
1551 						break;
1552 				if (curs == starts + bsize)
1553 					goto done;
1554 			}
1555 	}
1556 done:
1557 
1558 	/* Did not find anything */
1559 	if (bsize < THRESH)
1560 		return;
1561 
1562 #ifdef DEBUG
1563 	__CTRACE(__CTRACE_REFRESH, "quickch:bsize=%d, starts=%d, startw=%d, "
1564 	    "curw=%d, curs=%d, top=%d, bot=%d\n",
1565 	    bsize, starts, startw, curw, curs, top, bot);
1566 #endif
1567 
1568 	/*
1569 	 * Make sure that there is no overlap between the bottom and top
1570 	 * regions and the middle scrolled block.
1571 	 */
1572 	if (bot < curs)
1573 		bot = curs - 1;
1574 	if (top > starts)
1575 		top = starts;
1576 
1577 	n = startw - starts;
1578 
1579 #ifdef DEBUG
1580 	__CTRACE(__CTRACE_REFRESH, "#####################################\n");
1581 	for (i = 0; i < curscr->maxy; i++) {
1582 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1583 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n", curscr->alines[i]->hash);
1584 		for (j = 0; j < curscr->maxx; j++)
1585 			__CTRACE(__CTRACE_REFRESH, "%c",
1586 			    curscr->alines[i]->line[j].ch);
1587 		__CTRACE(__CTRACE_REFRESH, "\n");
1588 		__CTRACE(__CTRACE_REFRESH, " attr:");
1589 		for (j = 0; j < curscr->maxx; j++)
1590 			__CTRACE(__CTRACE_REFRESH, " %x",
1591 			    curscr->alines[i]->line[j].attr);
1592 		__CTRACE(__CTRACE_REFRESH, "\n");
1593 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1594 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
1595 		    __virtscr->alines[i]->hash);
1596 		__CTRACE(__CTRACE_REFRESH, " 0x%x ",
1597 		    __virtscr->alines[i]->flags);
1598 		for (j = 0; j < __virtscr->maxx; j++)
1599 			__CTRACE(__CTRACE_REFRESH, "%c",
1600 			    __virtscr->alines[i]->line[j].ch);
1601 		__CTRACE(__CTRACE_REFRESH, "\n");
1602 		__CTRACE(__CTRACE_REFRESH, " attr:");
1603 		for (j = 0; j < __virtscr->maxx; j++)
1604 			__CTRACE(__CTRACE_REFRESH, " %x",
1605 			    __virtscr->alines[i]->line[j].attr);
1606 		__CTRACE(__CTRACE_REFRESH, "\n");
1607 	}
1608 #endif
1609 
1610 #ifndef HAVE_WCHAR
1611 	if (buf[0].ch != ' ') {
1612 		for (i = 0; i < BLANKSIZE; i++) {
1613 			buf[i].ch = ' ';
1614 			buf[i].attr = 0;
1615 		}
1616 	}
1617 #else
1618 	if (buf[0].ch != (wchar_t)btowc((int)curscr->bch )) {
1619 		for (i = 0; i < BLANKSIZE; i++) {
1620 			buf[i].ch = (wchar_t)btowc((int)curscr->bch);
1621 			if (_cursesi_copy_nsp(curscr->bnsp, &buf[i]) == ERR)
1622 				return;
1623 			buf[i].attr = 0;
1624 			SET_WCOL(buf[i], 1);
1625 		}
1626 	}
1627 #endif /* HAVE_WCHAR */
1628 
1629 	if (__virtscr->maxx != last_hash_len) {
1630 		blank_hash = 0;
1631 		for (i = __virtscr->maxx; i > BLANKSIZE; i -= BLANKSIZE) {
1632 			blank_hash = __hash_more(buf, sizeof(buf), blank_hash);
1633 		}
1634 		blank_hash = __hash_more((char *)(void *)buf,
1635 		    i * sizeof(buf[0]), blank_hash);
1636 		/* cache result in static data - screen width doesn't change often */
1637 		last_hash_len = __virtscr->maxx;
1638 		last_hash = blank_hash;
1639 	} else
1640 		blank_hash = last_hash;
1641 
1642 	/*
1643 	 * Perform the rotation to maintain the consistency of curscr.
1644 	 * This is hairy since we are doing an *in place* rotation.
1645 	 * Invariants of the loop:
1646 	 * - I is the index of the current line.
1647 	 * - Target is the index of the target of line i.
1648 	 * - Tmp1 points to current line (i).
1649 	 * - Tmp2 and points to target line (target);
1650 	 * - Cur_period is the index of the end of the current period.
1651 	 *   (see below).
1652 	 *
1653 	 * There are 2 major issues here that make this rotation non-trivial:
1654 	 * 1.  Scrolling in a scrolling region bounded by the top
1655 	 *     and bottom regions determined (whose size is sc_region).
1656 	 * 2.  As a result of the use of the mod function, there may be a
1657 	 *     period introduced, i.e., 2 maps to 4, 4 to 6, n-2 to 0, and
1658 	 *     0 to 2, which then causes all odd lines not to be rotated.
1659 	 *     To remedy this, an index of the end ( = beginning) of the
1660 	 *     current 'period' is kept, cur_period, and when it is reached,
1661 	 *     the next period is started from cur_period + 1 which is
1662 	 *     guaranteed not to have been reached since that would mean that
1663 	 *     all records would have been reached. (think about it...).
1664 	 *
1665 	 * Lines in the rotation can have 3 attributes which are marked on the
1666 	 * line so that curscr is consistent with the visual screen.
1667 	 * 1.  Not dirty -- lines inside the scrolled block, top region or
1668 	 *                  bottom region.
1669 	 * 2.  Blank lines -- lines in the differential of the scrolling
1670 	 *		      region adjacent to top and bot regions
1671 	 *                    depending on scrolling direction.
1672 	 * 3.  Dirty line -- all other lines are marked dirty.
1673 	 */
1674 	sc_region = bot - top + 1;
1675 	i = top;
1676 	tmp1 = curscr->alines[top];
1677 	cur_period = top;
1678 	for (j = top; j <= bot; j++) {
1679 		target = (i - top + n + sc_region) % sc_region + top;
1680 		tmp2 = curscr->alines[target];
1681 		curscr->alines[target] = tmp1;
1682 		/* Mark block as clean and blank out scrolled lines. */
1683 		clp = curscr->alines[target];
1684 #ifdef DEBUG
1685 		__CTRACE(__CTRACE_REFRESH,
1686 		    "quickch: n=%d startw=%d curw=%d i = %d target=%d ",
1687 		    n, startw, curw, i, target);
1688 #endif
1689 		if ((target >= startw && target < curw) || target < top
1690 		    || target > bot)
1691 		{
1692 #ifdef DEBUG
1693 			__CTRACE(__CTRACE_REFRESH, " notdirty\n");
1694 #endif
1695 			__virtscr->alines[target]->flags &= ~__ISDIRTY;
1696 		} else
1697 			if ((n > 0 && target >= top && target < top + n) ||
1698 			    (n < 0 && target <= bot && target > bot + n))
1699 			{
1700 				if (clp->hash != blank_hash ||
1701 				    !lineeq(clp->line, clp->line + 1,
1702 					    (__virtscr->maxx - 1)) ||
1703 				    !celleq(clp->line, buf))
1704 				{
1705 					for (i = __virtscr->maxx;
1706 					    i > BLANKSIZE;
1707 					    i -= BLANKSIZE) {
1708 						(void) memcpy(clp->line + i -
1709 						    BLANKSIZE, buf, sizeof(buf));
1710 					}
1711 					(void) memcpy(clp->line , buf, i *
1712 					    sizeof(buf[0]));
1713 #ifdef DEBUG
1714 					__CTRACE(__CTRACE_REFRESH,
1715 					    " blanked out: dirty\n");
1716 #endif
1717 					clp->hash = blank_hash;
1718 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1719 				} else {
1720 #ifdef DEBUG
1721 					__CTRACE(__CTRACE_REFRESH,
1722 					    " -- blank line already: dirty\n");
1723 #endif
1724 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1725 				}
1726 			} else {
1727 #ifdef DEBUG
1728 				__CTRACE(__CTRACE_REFRESH, " -- dirty\n");
1729 #endif
1730 				__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1731 			}
1732 		if (target == cur_period) {
1733 			i = target + 1;
1734 			tmp1 = curscr->alines[i];
1735 			cur_period = i;
1736 		} else {
1737 			tmp1 = tmp2;
1738 			i = target;
1739 		}
1740 	}
1741 #ifdef DEBUG
1742 	__CTRACE(__CTRACE_REFRESH, "$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
1743 	for (i = 0; i < curscr->maxy; i++) {
1744 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1745 		for (j = 0; j < curscr->maxx; j++)
1746 			__CTRACE(__CTRACE_REFRESH, "%c",
1747 			    curscr->alines[i]->line[j].ch);
1748 		__CTRACE(__CTRACE_REFRESH, "\n");
1749 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1750 		for (j = 0; j < __virtscr->maxx; j++)
1751 			__CTRACE(__CTRACE_REFRESH, "%c",
1752 			    __virtscr->alines[i]->line[j].ch);
1753 		__CTRACE(__CTRACE_REFRESH, "\n");
1754 	}
1755 #endif
1756 	if (n != 0)
1757 		scrolln(starts, startw, curs, bot, top);
1758 }
1759 
1760 /*
1761  * scrolln --
1762  *	Scroll n lines, where n is starts - startw.
1763  */
1764 static void /* ARGSUSED */
1765 scrolln(int starts, int startw, int curs, int bot, int top)
1766 {
1767 	int	i, oy, ox, n;
1768 
1769 	oy = curscr->cury;
1770 	ox = curscr->curx;
1771 	n = starts - startw;
1772 
1773 	/*
1774 	 * XXX
1775 	 * The initial tests that set __noqch don't let us reach here unless
1776 	 * we have either cs + ho + SF/sf/SR/sr, or AL + DL.  SF/sf and SR/sr
1777 	 * scrolling can only shift the entire scrolling region, not just a
1778 	 * part of it, which means that the quickch() routine is going to be
1779 	 * sadly disappointed in us if we don't have cs as well.
1780 	 *
1781 	 * If cs, ho and SF/sf are set, can use the scrolling region.  Because
1782 	 * the cursor position after cs is undefined, we need ho which gives us
1783 	 * the ability to move to somewhere without knowledge of the current
1784 	 * location of the cursor.  Still call __mvcur() anyway, to update its
1785 	 * idea of where the cursor is.
1786 	 *
1787 	 * When the scrolling region has been set, the cursor has to be at the
1788 	 * last line of the region to make the scroll happen.
1789 	 *
1790 	 * Doing SF/SR or AL/DL appears faster on the screen than either sf/sr
1791 	 * or AL/DL, and, some terminals have AL/DL, sf/sr, and cs, but not
1792 	 * SF/SR.  So, if we're scrolling almost all of the screen, try and use
1793 	 * AL/DL, otherwise use the scrolling region.  The "almost all" is a
1794 	 * shameless hack for vi.
1795 	 */
1796 	if (n > 0) {
1797 		if (change_scroll_region != NULL && cursor_home != NULL &&
1798 		    (parm_index != NULL ||
1799 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1800 		    top > 3 || bot + 3 < __virtscr->maxy) &&
1801 		    scroll_forward != 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, bot, 0, 1);
1808 			if (parm_index != NULL)
1809 				tputs(tiparm(parm_index, n),
1810 				    0, __cputchar);
1811 			else
1812 				for (i = 0; i < n; i++)
1813 					tputs(scroll_forward, 0, __cputchar);
1814 			tputs(tiparm(change_scroll_region,
1815 			    0, (int)__virtscr->maxy - 1), 0, __cputchar);
1816 			__mvcur(bot, 0, 0, 0, 1);
1817 			tputs(cursor_home, 0, __cputchar);
1818 			__mvcur(0, 0, oy, ox, 1);
1819 			return;
1820 		}
1821 
1822 		/* Scroll up the block. */
1823 		if (parm_index != NULL && top == 0) {
1824 			__mvcur(oy, ox, bot, 0, 1);
1825 			tputs(tiparm(parm_index, n), 0, __cputchar);
1826 		} else
1827 			if (parm_delete_line != NULL) {
1828 				__mvcur(oy, ox, top, 0, 1);
1829 				tputs(tiparm(parm_delete_line, n),
1830 				    0, __cputchar);
1831 			} else
1832 				if (delete_line != NULL) {
1833 					__mvcur(oy, ox, top, 0, 1);
1834 					for (i = 0; i < n; i++)
1835 						tputs(delete_line, 0,
1836 						    __cputchar);
1837 				} else
1838 					if (scroll_forward != NULL && top == 0) {
1839 						__mvcur(oy, ox, bot, 0, 1);
1840 						for (i = 0; i < n; i++)
1841 							tputs(scroll_forward, 0,
1842 							    __cputchar);
1843 					} else
1844 						abort();
1845 
1846 		/* Push down the bottom region. */
1847 		__mvcur(top, 0, bot - n + 1, 0, 1);
1848 		if (parm_insert_line != NULL)
1849 			tputs(tiparm(parm_insert_line, n), 0, __cputchar);
1850 		else {
1851 			if (insert_line != NULL) {
1852 				for (i = 0; i < n; i++)
1853 					tputs(insert_line, 0, __cputchar);
1854 			} else
1855 				abort();
1856 		}
1857 		__mvcur(bot - n + 1, 0, oy, ox, 1);
1858 	} else {
1859 		/*
1860 		 * !!!
1861 		 * n < 0
1862 		 *
1863 		 * If cs, ho and SR/sr are set, can use the scrolling region.
1864 		 * See the above comments for details.
1865 		 */
1866 		if (change_scroll_region != NULL && cursor_home != NULL &&
1867 		    (parm_rindex != NULL ||
1868 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1869 		    top > 3 ||
1870 		    bot + 3 < __virtscr->maxy) && scroll_reverse != NULL)))
1871 		{
1872 			tputs(tiparm(change_scroll_region, top, bot),
1873 			    0, __cputchar);
1874 			__mvcur(oy, ox, 0, 0, 1);
1875 			tputs(cursor_home, 0, __cputchar);
1876 			__mvcur(0, 0, top, 0, 1);
1877 
1878 			if (parm_rindex != NULL)
1879 				tputs(tiparm(parm_rindex, -n),
1880 				    0, __cputchar);
1881 			else
1882 				for (i = n; i < 0; i++)
1883 					tputs(scroll_reverse, 0, __cputchar);
1884 			tputs(tiparm(change_scroll_region,
1885 			    0, (int) __virtscr->maxy - 1), 0, __cputchar);
1886 			__mvcur(top, 0, 0, 0, 1);
1887 			tputs(cursor_home, 0, __cputchar);
1888 			__mvcur(0, 0, oy, ox, 1);
1889 			return;
1890 		}
1891 
1892 		/* Preserve the bottom lines. */
1893 		__mvcur(oy, ox, bot + n + 1, 0, 1);
1894 		if (parm_rindex != NULL && bot == __virtscr->maxy)
1895 			tputs(tiparm(parm_rindex, -n), 0, __cputchar);
1896 		else {
1897 			if (parm_delete_line != NULL)
1898 				tputs(tiparm(parm_delete_line, -n),
1899 				    0, __cputchar);
1900 			else {
1901 				if (delete_line != NULL)
1902 					for (i = n; i < 0; i++)
1903 						tputs(delete_line,
1904 						    0, __cputchar);
1905 				else {
1906 					if (scroll_reverse != NULL &&
1907 					    bot == __virtscr->maxy)
1908 						for (i = n; i < 0; i++)
1909 							tputs(scroll_reverse, 0,
1910 							    __cputchar);
1911 					else
1912 						abort();
1913 				}
1914 			}
1915 		}
1916 		/* Scroll the block down. */
1917 		__mvcur(bot + n + 1, 0, top, 0, 1);
1918 		if (parm_insert_line != NULL)
1919 			tputs(tiparm(parm_insert_line, -n), 0, __cputchar);
1920 		else
1921 			if (insert_line != NULL)
1922 				for (i = n; i < 0; i++)
1923 					tputs(insert_line, 0, __cputchar);
1924 			else
1925 				abort();
1926 		__mvcur(top, 0, oy, ox, 1);
1927 	}
1928 }
1929 
1930 /*
1931  * __unsetattr --
1932  *	Unset attributes on curscr.  Leave standout, attribute and colour
1933  *	modes if necessary (!ms).  Always leave altcharset (xterm at least
1934  *	ignores a cursor move if we don't).
1935  */
1936 void /* ARGSUSED */
1937 __unsetattr(int checkms)
1938 {
1939 	int	isms;
1940 
1941 	if (checkms) {
1942 		if (!move_standout_mode)
1943 			isms = 1;
1944 		else
1945 			isms = 0;
1946 	} else
1947 		isms = 1;
1948 #ifdef DEBUG
1949 	__CTRACE(__CTRACE_REFRESH,
1950 	    "__unsetattr: checkms = %d, ms = %s, wattr = %08x\n",
1951 	    checkms, move_standout_mode ? "TRUE" : "FALSE", curscr->wattr);
1952 #endif
1953 
1954 	/*
1955 	 * Don't leave the screen in standout mode (check against ms).  Check
1956 	 * to see if we also turn off underscore, attributes and colour.
1957 	 */
1958 	if (curscr->wattr & __STANDOUT && isms) {
1959 		tputs(exit_standout_mode, 0, __cputchar);
1960 		curscr->wattr &= __mask_se;
1961 	}
1962 	/*
1963 	 * Don't leave the screen in underscore mode (check against ms).
1964 	 * Check to see if we also turn off attributes.  Assume that we
1965 	 * also turn off colour.
1966 	 */
1967 	if (curscr->wattr & __UNDERSCORE && isms) {
1968 		tputs(exit_underline_mode, 0, __cputchar);
1969 		curscr->wattr &= __mask_ue;
1970 	}
1971 	/*
1972 	 * Don't leave the screen with attributes set (check against ms).
1973 	 * Assume that also turn off colour.
1974 	 */
1975 	if (curscr->wattr & __TERMATTR && isms) {
1976 		tputs(exit_attribute_mode, 0, __cputchar);
1977 		curscr->wattr &= __mask_me;
1978 	}
1979 	/* Don't leave the screen with altcharset set (don't check ms). */
1980 	if (curscr->wattr & __ALTCHARSET) {
1981 		tputs(exit_alt_charset_mode, 0, __cputchar);
1982 		curscr->wattr &= ~__ALTCHARSET;
1983 	}
1984 	/* Don't leave the screen with colour set (check against ms). */
1985 	if (__using_color && isms)
1986 		__unset_color(curscr);
1987 }
1988 
1989 #ifdef HAVE_WCHAR
1990 /* compare two cells on screen, must have the same forground/background,
1991  * and the same sequence of non-spacing characters */
1992 static int
1993 celleq(__LDATA *x, __LDATA *y)
1994 {
1995 	nschar_t *xnp = x->nsp, *ynp = y->nsp;
1996 	int ret = ( x->ch == y->ch ) && ( x->attr == y->attr );
1997 
1998 	if (!ret)
1999 		return 0;
2000 	if (!xnp && !ynp)
2001 		return 1;
2002 	if ((xnp && !ynp) || (!xnp && ynp))
2003 		return 0;
2004 
2005 	while (xnp && ynp) {
2006 		if (xnp->ch != ynp->ch)
2007 			return 0;
2008 		xnp = xnp->next;
2009 		ynp = ynp->next;
2010 	}
2011 	return !xnp && !ynp;
2012 }
2013 
2014 /* compare two line segments */
2015 static int
2016 lineeq(__LDATA *xl, __LDATA *yl, size_t len)
2017 {
2018 	int i = 0;
2019 	__LDATA *xp = xl, *yp = yl;
2020 
2021 	for (i = 0; i < len; i++, xp++, yp++) {
2022 		if (!celleq(xp, yp))
2023 			return 0;
2024 	}
2025 	return 1;
2026 }
2027 
2028 /*
2029  * Output the non-spacing characters associated with the given character
2030  * cell to the screen.
2031  */
2032 
2033 void
2034 __cursesi_putnsp(nschar_t *nsp, const int wy, const int wx)
2035 {
2036 	nschar_t *p;
2037 
2038 	/* this shuts up gcc warnings about wx and wy not being used */
2039 	if (wx > wy) {
2040 	}
2041 
2042 	p = nsp;
2043 	while (p != NULL) {
2044 		__cputwchar((int)p->ch);
2045 #ifdef DEBUG
2046 		__CTRACE(__CTRACE_REFRESH,
2047 		       "_cursesi_putnsp: (%d,%d) non-spacing putwchar(0x%x)\n",
2048 			 wy, wx - 1, p->ch);
2049 #endif
2050 		p = p->next;
2051 	}
2052 }
2053 
2054 #endif /* HAVE_WCHAR */
2055