xref: /netbsd-src/lib/libcurses/refresh.c (revision c9496f6b604074a9451a67df576a5b423068e71e)
1 /*	$NetBSD: refresh.c,v 1.88 2017/03/20 20:42:39 christos 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 1.88 2017/03/20 20:42:39 christos 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 int	makech(int);
50 static void	quickch(void);
51 static void	scrolln(int, int, int, int, int);
52 
53 static int	_wnoutrefresh(WINDOW *, int, int, int, int, int, int);
54 
55 #ifdef HAVE_WCHAR
56 int cellcmp( __LDATA *, __LDATA * );
57 int linecmp( __LDATA *, __LDATA *, size_t );
58 #endif /* HAVE_WCHAR */
59 
60 #define	CHECK_INTERVAL		5 /* Change N lines before checking typeahead */
61 
62 #ifndef _CURSES_USE_MACROS
63 
64 /*
65  * refresh --
66  *	Make the current screen look like "stdscr" over the area covered by
67  *	stdscr.
68  */
69 int
70 refresh(void)
71 {
72 
73 	return wrefresh(stdscr);
74 }
75 
76 #endif
77 
78 /*
79  * wnoutrefresh --
80  *	Add the contents of "win" to the virtual window.
81  */
82 int
83 wnoutrefresh(WINDOW *win)
84 {
85 
86 #ifdef DEBUG
87 	__CTRACE(__CTRACE_REFRESH, "wnoutrefresh: win %p\n", win);
88 #endif
89 
90 	return _wnoutrefresh(win, 0, 0, win->begy, win->begx,
91 	    win->maxy, win->maxx);
92 }
93 
94 /*
95  * pnoutrefresh --
96  *	Add the contents of "pad" to the virtual window.
97  */
98 int
99 pnoutrefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
100 	     int smaxy, int smaxx)
101 {
102 	int pmaxy, pmaxx;
103 
104 #ifdef DEBUG
105 	__CTRACE(__CTRACE_REFRESH, "pnoutrefresh: pad %p, flags 0x%08x\n",
106 	    pad, pad->flags);
107 	__CTRACE(__CTRACE_REFRESH,
108 	    "pnoutrefresh: (%d, %d), (%d, %d), (%d, %d)\n",
109 	    pbegy, pbegx, sbegy, sbegx, smaxy, smaxx);
110 #endif
111 
112 	/* SUS says if these are negative, they should be treated as zero */
113 	if (pbegy < 0)
114 		pbegy = 0;
115 	if (pbegx < 0)
116 		pbegx = 0;
117 	if (sbegy < 0)
118 		sbegy = 0;
119 	if (sbegx < 0)
120 		sbegx = 0;
121 
122 	/* Calculate rectangle on pad - used by _wnoutrefresh */
123 	pmaxy = pbegy + smaxy - sbegy + 1;
124 	pmaxx = pbegx + smaxx - sbegx + 1;
125 
126 	/* Check rectangle fits in pad */
127 	if (pmaxy > pad->maxy - pad->begy)
128 		pmaxy = pad->maxy - pad->begy;
129 	if (pmaxx > pad->maxx - pad->begx)
130 		pmaxx = pad->maxx - pad->begx;
131 
132 	if (smaxy - sbegy < 0 || smaxx - sbegx < 0 )
133 		return ERR;
134 
135 	return _wnoutrefresh(pad,
136 	    pad->begy + pbegy, pad->begx + pbegx, pad->begy + sbegy,
137 	    pad->begx + sbegx, pmaxy, pmaxx);
138 }
139 
140 /*
141  * _wnoutrefresh --
142  *	Does the grunt work for wnoutrefresh to the given screen.
143  *	Copies the part of the window given by the rectangle
144  *	(begy, begx) to (maxy, maxx) at screen position (wbegy, wbegx).
145  */
146 static int
147 _wnoutrefresh(WINDOW *win, int begy, int begx, int wbegy, int wbegx,
148               int maxy, int maxx)
149 {
150 	SCREEN *screen = win->screen;
151 	short	sy, wy, wx, y_off, x_off, mx, dy_off, dx_off, endy;
152 	__LINE	*wlp, *vlp, *dwlp;
153 	WINDOW	*sub_win, *orig, *swin, *dwin;
154 
155 #ifdef DEBUG
156 	__CTRACE(__CTRACE_REFRESH, "_wnoutrefresh: win %p, flags 0x%08x\n",
157 	    win, win->flags);
158 	__CTRACE(__CTRACE_REFRESH,
159 	    "_wnoutrefresh: (%d, %d), (%d, %d), (%d, %d)\n",
160 	    begy, begx, wbegy, wbegx, maxy, maxx);
161 #endif
162 
163 	if (screen->curwin)
164 		return OK;
165 
166 	swin = dwin = win;
167 	if (win->flags & __ISDERWIN)
168 		swin = win->orig;
169 
170 	/*
171 	 * Recurse through any sub-windows, mark as dirty lines on the parent
172 	 * window that are dirty on the sub-window and clear the dirty flag on
173 	 * the sub-window.
174 	 */
175 	if (dwin->orig == 0) {
176 		orig = dwin;
177 		for (sub_win = dwin->nextp; sub_win != orig;
178 		    sub_win = sub_win->nextp) {
179 			if (sub_win->flags & __ISDERWIN)
180 				continue;
181 #ifdef DEBUG
182 			__CTRACE(__CTRACE_REFRESH,
183 			    "wnout_refresh: win %p, sub_win %p\n",
184 			    orig, sub_win);
185 #endif
186 			for (sy = 0; sy < sub_win->maxy; sy++) {
187 				if (sub_win->alines[sy]->flags & __ISDIRTY) {
188 					orig->alines[sy + sub_win->begy - orig->begy]->flags
189 					    |= __ISDIRTY;
190 					sub_win->alines[sy]->flags
191 					    &= ~__ISDIRTY;
192 				}
193 				if (sub_win->alines[sy]->flags & __ISFORCED) {
194 					orig->alines[sy + sub_win->begy - orig->begy]->flags
195 					    |= __ISFORCED;
196 					sub_win->alines[sy]->flags
197 					    &= ~__ISFORCED;
198 				}
199 			}
200 		}
201 	}
202 
203 	/* Check that cursor position on "win" is valid for "__virtscr" */
204 	if (dwin->cury + wbegy - begy < screen->__virtscr->maxy &&
205 	    dwin->cury + wbegy - begy >= 0 && dwin->cury < maxy - begy)
206 		screen->__virtscr->cury = dwin->cury + wbegy - begy;
207 	if (dwin->curx + wbegx - begx < screen->__virtscr->maxx &&
208 	    dwin->curx + wbegx - begx >= 0 && dwin->curx < maxx - begx)
209 		screen->__virtscr->curx = dwin->curx + wbegx - begx;
210 
211 	/* Copy the window flags from "win" to "__virtscr" */
212 	if (dwin->flags & __CLEAROK) {
213 		if (dwin->flags & __FULLWIN)
214 			screen->__virtscr->flags |= __CLEAROK;
215 		dwin->flags &= ~__CLEAROK;
216 	}
217 	screen->__virtscr->flags &= ~__LEAVEOK;
218 	screen->__virtscr->flags |= dwin->flags;
219 
220 	if ((dwin->flags & __ISDERWIN) != 0)
221 		endy = begy + maxy;
222 	else
223 		endy = maxy;
224 
225 	for (wy = begy, y_off = wbegy, dy_off = 0; wy < endy &&
226 	    y_off < screen->__virtscr->maxy; wy++, y_off++, dy_off++)
227 	{
228 		wlp = swin->alines[wy];
229 		dwlp = dwin->alines[dy_off];
230 #ifdef DEBUG
231 		__CTRACE(__CTRACE_REFRESH,
232 		    "_wnoutrefresh: wy %d\tf %d\tl %d\tflags %x\n",
233 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
234 
235 		if ((dwin->flags & __ISDERWIN) != 0) {
236 			__CTRACE(__CTRACE_REFRESH,
237 			"_wnoutrefresh: derwin wy %d\tf %d\tl %d\tflags %x\n",
238 			dy_off, *dwlp->firstchp, *dwlp->lastchp, dwlp->flags);
239 			__CTRACE(__CTRACE_REFRESH,
240 			"_wnoutrefresh: derwin maxx %d\tch_off %d\n",
241 			dwin->maxx, dwin->ch_off);
242 		}
243 #endif
244 		if (((wlp->flags & (__ISDIRTY | __ISFORCED)) == 0) &&
245 		    ((dwlp->flags & (__ISDIRTY | __ISFORCED)) == 0))
246 			continue;
247 		vlp = screen->__virtscr->alines[y_off];
248 
249 		if ((*wlp->firstchp < maxx + swin->ch_off &&
250 		    *wlp->lastchp >= swin->ch_off) ||
251 		    ((((dwin->flags & __ISDERWIN) != 0) &&
252 		     (*dwlp->firstchp < dwin->maxx + dwin->ch_off &&
253 		      *dwlp->lastchp >= dwin->ch_off))))
254 		{
255 			/* Set start column */
256 			wx = begx;
257 			x_off = wbegx;
258 			dx_off = 0;
259 			/*
260 			 * if a derwin then source change pointers aren't
261 			 * relevant.
262 			 */
263 			if ((dwin->flags & __ISDERWIN) != 0)
264 				mx = wx + maxx;
265 			else {
266 				if (*wlp->firstchp - swin->ch_off > 0) {
267 					wx += *wlp->firstchp - swin->ch_off;
268 					x_off += *wlp->firstchp - swin->ch_off;
269 				}
270 				mx = maxx;
271 				if (mx > *wlp->lastchp - swin->ch_off + 1)
272 					mx = *dwlp->lastchp - dwin->ch_off + 1;
273 				if (x_off + (mx - wx) > screen->__virtscr->maxx)
274 					mx -= (x_off + maxx) -
275 					    screen->__virtscr->maxx;
276 			}
277 
278 			/* Copy line from "win" to "__virtscr". */
279 			while (wx < mx) {
280 #ifdef DEBUG
281 				__CTRACE(__CTRACE_REFRESH,
282 				    "_wnoutrefresh: copy from %d, "
283 				    "%d to %d, %d: %s, 0x%x",
284 				    wy, wx, y_off, x_off,
285 				    unctrl(wlp->line[wx].ch),
286 				    wlp->line[wx].attr);
287 #endif
288 				/* Copy character */
289 				vlp->line[x_off].ch = wlp->line[wx].ch;
290 				/* Copy attributes  */
291 				vlp->line[x_off].attr = wlp->line[wx].attr;
292 				/* Check for nca conflict with colour */
293 				if ((vlp->line[x_off].attr & __COLOR) &&
294 				    (vlp->line[x_off].attr & screen->nca))
295 					vlp->line[x_off].attr &= ~__COLOR;
296 				if (win->flags & __ISDERWIN) {
297 					dwlp->line[dx_off].ch =
298 						wlp->line[wx].ch;
299 					dwlp->line[dx_off].attr =
300 						wlp->line[wx].attr;
301 				}
302 
303 #ifdef HAVE_WCHAR
304 				if (wlp->line[wx].ch
305 				    == (wchar_t)btowc((int) win->bch)) {
306 					vlp->line[x_off].ch = win->bch;
307 					SET_WCOL(vlp->line[x_off], 1);
308 					if (_cursesi_copy_nsp(win->bnsp,
309 							      &vlp->line[x_off])
310 					    == ERR)
311 						return ERR;
312 					if (win->flags & __ISDERWIN) {
313 						dwlp->line[dx_off].ch =
314 							win->bch;
315 						SET_WCOL(dwlp->line[dx_off], 1);
316 						if (_cursesi_copy_nsp(win->bnsp,
317 						     &dwlp->line[dx_off])
318 						    == ERR)
319 							return ERR;
320 					}
321 				}
322 #endif /* HAVE_WCHAR */
323 #ifdef DEBUG
324 				__CTRACE(__CTRACE_REFRESH, " = %s, 0x%x\n",
325 				    unctrl(vlp->line[x_off].ch),
326 				    vlp->line[x_off].attr);
327 #endif
328 				wx++;
329 				x_off++;
330 				dx_off++;
331 			}
332 
333 			/* Set flags on "__virtscr" and unset on "win". */
334 			if (wlp->flags & __ISPASTEOL)
335 				vlp->flags |= __ISPASTEOL;
336 			else
337 				vlp->flags &= ~__ISPASTEOL;
338 			if (wlp->flags & __ISDIRTY)
339 				vlp->flags |= __ISDIRTY;
340 			if (wlp->flags & __ISFORCED)
341 				vlp->flags |= __ISFORCED;
342 
343 #ifdef DEBUG
344 			__CTRACE(__CTRACE_REFRESH,
345 			    "win: firstch = %d, lastch = %d\n",
346 			    *wlp->firstchp, *wlp->lastchp);
347 			if (win->flags & __ISDERWIN) {
348 				__CTRACE(__CTRACE_REFRESH,
349 				    "derwin: fistch = %d, lastch = %d\n",
350 				    *dwlp->firstchp, *dwlp->lastchp);
351 			}
352 #endif
353 			/* Set change pointers on "__virtscr". */
354 			if (*vlp->firstchp >
355 				*wlp->firstchp + wbegx - win->ch_off)
356 					*vlp->firstchp =
357 					    *wlp->firstchp + wbegx - win->ch_off;
358 			if (*vlp->lastchp <
359 				*wlp->lastchp + wbegx - win->ch_off)
360 					*vlp->lastchp =
361 					    *wlp->lastchp + wbegx - win->ch_off;
362 
363 			if (win->flags & __ISDERWIN) {
364 				if (*vlp->firstchp >
365 				    *dwlp->firstchp + wbegx - dwin->ch_off)
366 				{
367 					*vlp->firstchp =
368 					    *dwlp->firstchp + wbegx
369 						- dwin->ch_off;
370 					vlp->flags |= __ISDIRTY;
371 				}
372 
373 				if (*vlp->lastchp <
374 				    *dwlp->lastchp + wbegx - dwin->ch_off)
375 				{
376 					*vlp->lastchp = *dwlp->lastchp
377 					    + wbegx - dwin->ch_off;
378 					vlp->flags |= __ISDIRTY;
379 				}
380 			}
381 
382 #ifdef DEBUG
383 			__CTRACE(__CTRACE_REFRESH,
384 			    "__virtscr: firstch = %d, lastch = %d\n",
385 			    *vlp->firstchp, *vlp->lastchp);
386 #endif
387 			/*
388 			 * Unset change pointers only if a window and we
389 			 * are not forcing a redraw. A pad can be displayed
390 			 * again without any of the contents changing.
391 			 */
392 			if ((!(win->flags & __ISPAD)) ||
393 			    ((wlp->flags & __ISFORCED) == __ISFORCED))
394 			{
395 				/* Set change pointers on "win". */
396 				if (*wlp->firstchp >= win->ch_off)
397 					*wlp->firstchp = maxx + win->ch_off;
398 				if (*wlp->lastchp < maxx + win->ch_off)
399 					*wlp->lastchp = win->ch_off;
400 				if ((*wlp->lastchp < *wlp->firstchp) ||
401 				    (*wlp->firstchp >= maxx + win->ch_off) ||
402 				    (*wlp->lastchp <= win->ch_off)) {
403 #ifdef DEBUG
404 					__CTRACE(__CTRACE_REFRESH,
405 					    "_wnoutrefresh: "
406 					    "line %d notdirty\n", wy);
407 #endif
408 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
409 				}
410 			}
411 		}
412 	}
413 	return OK;
414 }
415 
416 /*
417  * wrefresh --
418  *	Make the current screen look like "win" over the area covered by
419  *	win.
420  */
421 int
422 wrefresh(WINDOW *win)
423 {
424 	int retval;
425 	int pbegx, pbegy;
426 
427 #ifdef DEBUG
428 	__CTRACE(__CTRACE_REFRESH, "wrefresh: win %p\n", win);
429 #endif
430 
431 	_cursesi_screen->curwin = (win == _cursesi_screen->curscr);
432 	if (!_cursesi_screen->curwin) {
433 		pbegx = pbegy = 0;
434 		if ((win->flags & __ISDERWIN) == __ISDERWIN) {
435 			pbegx = win->derx;
436 			pbegy = win->dery;
437 #ifdef DEBUG
438 	__CTRACE(__CTRACE_REFRESH, "wrefresh: derwin, begy = %d, begx = %x\n",
439 		pbegy, pbegx);
440 #endif
441 		}
442 		retval = _wnoutrefresh(win, pbegy, pbegx, win->begy, win->begx,
443 		    win->maxy, win->maxx);
444 	} else
445 		retval = OK;
446 	if (retval == OK) {
447 		retval = doupdate();
448 		if (!(win->flags & __LEAVEOK)) {
449 			win->cury = max(0, curscr->cury - win->begy);
450 			win->curx = max(0, curscr->curx - win->begx);
451 		}
452 	}
453 	_cursesi_screen->curwin = 0;
454 	return retval;
455 }
456 
457  /*
458  * prefresh --
459  *	Make the current screen look like "pad" over the area coverd by
460  *	the specified area of pad.
461  */
462 int
463 prefresh(WINDOW *pad, int pbegy, int pbegx, int sbegy, int sbegx,
464 	int smaxy, int smaxx)
465 {
466 	int retval;
467 
468 #ifdef DEBUG
469 	__CTRACE(__CTRACE_REFRESH, "prefresh: pad %p, flags 0x%08x\n",
470 	    pad, pad->flags);
471 #endif
472 	/* Retain values in case pechochar() is called. */
473 	pad->pbegy = pbegy;
474 	pad->pbegx = pbegx;
475 	pad->sbegy = sbegy;
476 	pad->sbegx = sbegx;
477 	pad->smaxy = smaxy;
478 	pad->smaxx = smaxx;
479 
480 	/* Use pnoutrefresh() to avoid duplicating code here */
481 	retval = pnoutrefresh(pad, pbegy, pbegx, sbegy, sbegx, smaxy, smaxx);
482 	if (retval == OK) {
483 		retval = doupdate();
484 		if (!(pad->flags & __LEAVEOK)) {
485 			pad->cury = max(0, curscr->cury - pad->begy);
486 			pad->curx = max(0, curscr->curx - pad->begx);
487 		}
488 	}
489 	return retval;
490 }
491 
492 /*
493  * doupdate --
494  *	Make the current screen look like the virtual window "__virtscr".
495  */
496 int
497 doupdate(void)
498 {
499 	WINDOW	*win;
500 	__LINE	*wlp, *vlp;
501 	short	 wy;
502 	int	 dnum, was_cleared, changed;
503 #ifdef HAVE_WCHAR
504 	__LDATA *lp;
505 	nschar_t *np;
506 	int x;
507 #endif /* HAVE_WCHAR */
508 
509 	/* Check if we need to restart ... */
510 	if (_cursesi_screen->endwin)
511 		__restartwin();
512 
513 	if (_cursesi_screen->curwin)
514 		win = curscr;
515 	else
516 		win = _cursesi_screen->__virtscr;
517 
518 	/* Initialize loop parameters. */
519 	_cursesi_screen->ly = curscr->cury;
520 	_cursesi_screen->lx = curscr->curx;
521 	wy = 0;
522 
523 	if (!_cursesi_screen->curwin) {
524 		for (wy = 0; wy < win->maxy; wy++) {
525 			wlp = win->alines[wy];
526 			if (wlp->flags & __ISDIRTY) {
527 #ifndef HAVE_WCHAR
528 				wlp->hash = __hash(wlp->line,
529 				    (size_t)(win->maxx * __LDATASIZE));
530 #else
531 				wlp->hash = 0;
532 				for ( x = 0; x < win->maxx; x++ ) {
533 					lp = &wlp->line[ x ];
534 					wlp->hash = __hash_more( &lp->ch,
535 						sizeof(wchar_t), wlp->hash );
536 					wlp->hash = __hash_more( &lp->attr,
537 						sizeof(attr_t), wlp->hash );
538 					np = lp->nsp;
539 					if (np) {
540 						while (np) {
541 							wlp->hash
542 							    = __hash_more(
543 								&np->ch,
544 								sizeof(wchar_t),
545 								wlp->hash);
546 							np = np->next;
547 						}
548 					}
549 				}
550 #endif /* HAVE_WCHAR */
551 			}
552 		}
553 	}
554 
555 	was_cleared = 0;
556 	if ((win->flags & __CLEAROK) || (curscr->flags & __CLEAROK) ||
557 	    _cursesi_screen->curwin)
558 	{
559 		if (curscr->wattr & __COLOR)
560 			__unsetattr(0);
561 		tputs(clear_screen, 0, __cputchar);
562 		_cursesi_screen->ly = 0;
563 		_cursesi_screen->lx = 0;
564 		if (!_cursesi_screen->curwin) {
565 			curscr->flags &= ~__CLEAROK;
566 			curscr->cury = 0;
567 			curscr->curx = 0;
568 			werase(curscr);
569 		}
570 		__touchwin(win);
571 		win->flags &= ~__CLEAROK;
572 		/* note we cleared for later */
573 		was_cleared = 1;
574 	}
575 	if (!cursor_address) {
576 		if (win->curx != 0)
577 			__cputchar('\n');
578 		if (!_cursesi_screen->curwin)
579 			werase(curscr);
580 	}
581 #ifdef DEBUG
582 	__CTRACE(__CTRACE_REFRESH, "doupdate: (%p): curwin = %d\n", win,
583 	    _cursesi_screen->curwin);
584 	__CTRACE(__CTRACE_REFRESH, "doupdate: \tfirstch\tlastch\n");
585 #endif
586 
587 	if (!_cursesi_screen->curwin) {
588 		/*
589 		 * Invoke quickch() only if more than a quarter of the lines
590 		 * in the window are dirty.
591 		 */
592 		for (wy = 0, dnum = 0; wy < win->maxy; wy++)
593 			if (win->alines[wy]->flags & __ISDIRTY)
594 				dnum++;
595 		if (!__noqch && dnum > (int) win->maxy / 4)
596 			quickch();
597 	}
598 
599 #ifdef DEBUG
600 	{
601 		int	i, j;
602 
603 		__CTRACE(__CTRACE_REFRESH,
604 		    "#####################################\n");
605 		__CTRACE(__CTRACE_REFRESH,
606 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
607 		    stdscr, curscr, _cursesi_screen->__virtscr);
608 		for (i = 0; i < curscr->maxy; i++) {
609 			__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
610 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
611 			    curscr->alines[i]->hash);
612 			for (j = 0; j < curscr->maxx; j++)
613 				__CTRACE(__CTRACE_REFRESH, "%c",
614 				    curscr->alines[i]->line[j].ch);
615 			__CTRACE(__CTRACE_REFRESH, "\n");
616 			__CTRACE(__CTRACE_REFRESH, " attr:");
617 			for (j = 0; j < curscr->maxx; j++)
618 				__CTRACE(__CTRACE_REFRESH, " %x",
619 				    curscr->alines[i]->line[j].attr);
620 			__CTRACE(__CTRACE_REFRESH, "\n");
621 			__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
622 			__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
623 			    win->alines[i]->hash);
624 			__CTRACE(__CTRACE_REFRESH, " 0x%x ",
625 			    win->alines[i]->flags);
626 			for (j = 0; j < win->maxx; j++)
627 				__CTRACE(__CTRACE_REFRESH, "%c",
628 				    win->alines[i]->line[j].ch);
629 			__CTRACE(__CTRACE_REFRESH, "\n");
630 			__CTRACE(__CTRACE_REFRESH, " attr:");
631 			for (j = 0; j < win->maxx; j++)
632 				__CTRACE(__CTRACE_REFRESH, " %x",
633 				    win->alines[i]->line[j].attr);
634 			__CTRACE(__CTRACE_REFRESH, "\n");
635 #ifdef HAVE_WCHAR
636 			__CTRACE(__CTRACE_REFRESH, " nsp:");
637 			for (j = 0; j < curscr->maxx; j++)
638 				__CTRACE(__CTRACE_REFRESH, " %p",
639 				    win->alines[i]->line[j].nsp);
640 			__CTRACE(__CTRACE_REFRESH, "\n");
641 			__CTRACE(__CTRACE_REFRESH, " bnsp:");
642 			for (j = 0; j < curscr->maxx; j++)
643 				__CTRACE(__CTRACE_REFRESH, " %p",
644 				    win->bnsp);
645 			__CTRACE(__CTRACE_REFRESH, "\n");
646 #endif /* HAVE_WCHAR */
647 		}
648 	}
649 #endif /* DEBUG */
650 
651 	changed = 0;
652 	for (wy = 0; wy < win->maxy; wy++) {
653 		wlp = win->alines[wy];
654 		vlp = _cursesi_screen->__virtscr->alines[win->begy + wy];
655 /* XXX: remove this debug */
656 #ifdef DEBUG
657 		__CTRACE(__CTRACE_REFRESH,
658 		    "doupdate: wy %d\tf: %d\tl:%d\tflags %x\n",
659 		    wy, *wlp->firstchp, *wlp->lastchp, wlp->flags);
660 #endif /* DEBUG */
661 		if (!_cursesi_screen->curwin)
662 			curscr->alines[wy]->hash = wlp->hash;
663 		if (wlp->flags & __ISDIRTY || wlp->flags & __ISFORCED) {
664 #ifdef DEBUG
665 			__CTRACE(__CTRACE_REFRESH,
666 			    "doupdate: [ISDIRTY]wy:%d\tf:%d\tl:%d\n", wy,
667 			    *wlp->firstchp, *wlp->lastchp);
668 #endif /* DEBUG */
669 			/*
670 			 * We have just cleared so don't force an update
671 			 * otherwise we spray neeedless blanks to a cleared
672 			 * screen.
673 			 */
674 			if (was_cleared == 1)
675 				win->alines[wy]->flags &= ~__ISFORCED;
676 
677 			if (makech(wy) == ERR)
678 				return ERR;
679 			else {
680 				if (*wlp->firstchp >= 0)
681 					*wlp->firstchp = win->maxx;
682 				if (*wlp->lastchp < win->maxx)
683 					*wlp->lastchp = win->ch_off;
684 				if (*wlp->lastchp < *wlp->firstchp) {
685 #ifdef DEBUG
686 					__CTRACE(__CTRACE_REFRESH,
687 					    "doupdate: line %d notdirty\n", wy);
688 #endif /* DEBUG */
689 					wlp->flags &= ~(__ISDIRTY | __ISFORCED);
690 				}
691 
692 				/* Check if we have input after
693 				 * changing N lines. */
694 				if (_cursesi_screen->checkfd != -1 &&
695 				    ++changed == CHECK_INTERVAL)
696 				{
697 					struct pollfd fds[1];
698 
699 					/* If we have input, abort. */
700 					fds[0].fd = _cursesi_screen->checkfd;
701 					fds[0].events = POLLIN;
702 					if (poll(fds, 1, 0) > 0)
703 						goto cleanup;
704 					changed = 0;
705 				}
706 			}
707 		}
708 
709 		/*
710 		 * virtscr is now synced for the line, unset the change
711 		 * pointers.
712 		 */
713 		if (*vlp->firstchp >= 0)
714 			*vlp->firstchp = _cursesi_screen->__virtscr->maxx;
715 		if (*vlp->lastchp <= _cursesi_screen->__virtscr->maxx)
716 			*vlp->lastchp = 0;
717 
718 #ifdef DEBUG
719 		__CTRACE(__CTRACE_REFRESH, "\t%d\t%d\n",
720 		    *wlp->firstchp, *wlp->lastchp);
721 #endif /* DEBUG */
722 	}
723 
724 #ifdef DEBUG
725 	__CTRACE(__CTRACE_REFRESH, "doupdate: ly=%d, lx=%d\n",
726 	    _cursesi_screen->ly, _cursesi_screen->lx);
727 #endif /* DEBUG */
728 
729 	if (_cursesi_screen->curwin)
730 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
731 			win->cury, win->curx);
732 	else {
733 		if (win->flags & __LEAVEOK) {
734 			curscr->cury = _cursesi_screen->ly;
735 			curscr->curx = _cursesi_screen->lx;
736 		} else {
737 			domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
738 				win->cury, win->curx);
739 			curscr->cury = win->cury;
740 			curscr->curx = win->curx;
741 		}
742 	}
743 
744 cleanup:
745 	/* Don't leave the screen with attributes set. */
746 	__unsetattr(0);
747 #ifdef DEBUG
748 #ifdef HAVE_WCHAR
749 	{
750 		int	i, j;
751 
752 		__CTRACE(__CTRACE_REFRESH,
753 		    "***********after*****************\n");
754 		__CTRACE(__CTRACE_REFRESH,
755 		    "stdscr(%p)-curscr(%p)-__virtscr(%p)\n",
756 		    stdscr, curscr, _cursesi_screen->__virtscr);
757 		for (i = 0; i < curscr->maxy; i++) {
758 			for (j = 0; j < curscr->maxx; j++)
759 				__CTRACE(__CTRACE_REFRESH,
760 				    "[%d,%d](%x,%x,%p)-(%x,%x,%p)\n",
761 				    i, j,
762 				    curscr->alines[i]->line[j].ch,
763 				    curscr->alines[i]->line[j].attr,
764 				    curscr->alines[i]->line[j].nsp,
765 				    _cursesi_screen->__virtscr->alines[i]->line[j].ch,
766 				    _cursesi_screen->__virtscr->alines[i]->line[j].attr,
767 				    _cursesi_screen->__virtscr->alines[i]->line[j].nsp);
768 		}
769 	}
770 #endif /* HAVE_WCHAR */
771 #endif /* DEBUG */
772 	return fflush(_cursesi_screen->outfd) == EOF ? ERR : OK;
773 }
774 
775 /*
776  * makech --
777  *	Make a change on the screen.
778  */
779 static int
780 makech(int wy)
781 {
782 	WINDOW	*win;
783 	static __LDATA blank;
784 	__LDATA *nsp, *csp, *cp, *cep;
785 	__LINE *wlp;
786 	size_t	clsp, nlsp;	/* Last space in lines. */
787 	int	lch, wx;
788 	const char	*ce;
789 	attr_t	lspc;		/* Last space colour */
790 	attr_t	off, on;
791 
792 #ifdef __GNUC__
793 	nlsp = lspc = 0;	/* XXX gcc -Wuninitialized */
794 #endif
795 	if (_cursesi_screen->curwin)
796 		win = curscr;
797 	else
798 		win = __virtscr;
799 #ifdef HAVE_WCHAR
800 	blank.ch = (wchar_t)btowc((int) win->bch);
801 	blank.attr = 0;
802 	if (_cursesi_copy_nsp(win->bnsp, &blank) == ERR)
803 		return ERR;
804 	SET_WCOL(blank, 1);
805 #endif /* HAVE_WCHAR */
806 #ifdef DEBUG
807 #if HAVE_WCHAR
808 	{
809 		int x;
810 		__LDATA *lp, *vlp;
811 
812 		__CTRACE(__CTRACE_REFRESH,
813 		    "[makech-before]wy=%d,curscr(%p)-__virtscr(%p)\n",
814 		    wy, curscr, __virtscr);
815 		for (x = 0; x < curscr->maxx; x++) {
816 			lp = &curscr->alines[wy]->line[x];
817 			vlp = &__virtscr->alines[wy]->line[x];
818 			__CTRACE(__CTRACE_REFRESH,
819 			    "[%d,%d](%x,%x,%x,%x,%p)-"
820 			    "(%x,%x,%x,%x,%p)\n",
821 			    wy, x, lp->ch, lp->attr,
822 			    win->bch, win->battr, lp->nsp,
823 			    vlp->ch, vlp->attr,
824 			    win->bch, win->battr, vlp->nsp);
825 		}
826 	}
827 #endif /* HAVE_WCHAR */
828 #endif /* DEBUG */
829 	/* Is the cursor still on the end of the last line? */
830 	if (wy > 0 && curscr->alines[wy - 1]->flags & __ISPASTEOL) {
831 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx,
832 			_cursesi_screen->ly + 1, 0);
833 		_cursesi_screen->ly++;
834 		_cursesi_screen->lx = 0;
835 	}
836 	wlp = win->alines[wy];
837 	wx = *win->alines[wy]->firstchp;
838 	if (wx < 0)
839 		wx = 0;
840 	else
841 		if (wx >= win->maxx)
842 			return (OK);
843 	lch = *win->alines[wy]->lastchp;
844 	if (lch < 0)
845 		return OK;
846 	else
847 		if (lch >= (int) win->maxx)
848 			lch = win->maxx - 1;
849 
850 	if (_cursesi_screen->curwin) {
851 		csp = &blank;
852 #ifdef DEBUG
853 		__CTRACE(__CTRACE_REFRESH, "makech: csp is blank\n");
854 #endif /* DEBUG */
855 	} else {
856 		csp = &curscr->alines[wy]->line[wx];
857 #ifdef DEBUG
858 		__CTRACE(__CTRACE_REFRESH,
859 		    "makech: csp is on curscr:(%d,%d)\n", wy, wx);
860 #endif /* DEBUG */
861 	}
862 
863 	nsp = &win->alines[wy]->line[wx];
864 #ifdef DEBUG
865 	if (_cursesi_screen->curwin)
866 		__CTRACE(__CTRACE_REFRESH,
867 		    "makech: nsp is at curscr:(%d,%d)\n", wy, wx);
868 	else
869 		__CTRACE(__CTRACE_REFRESH,
870 		    "makech: nsp is at __virtscr:(%d,%d)\n", wy, wx);
871 #endif /* DEBUG */
872 	if (clr_eol && !_cursesi_screen->curwin) {
873 		cp = &win->alines[wy]->line[win->maxx - 1];
874 		lspc = cp->attr & __COLOR;
875 #ifndef HAVE_WCHAR
876 		while (cp->ch == ' ' && cp->attr == lspc) /* XXX */
877 			if (cp-- <= win->alines[wy]->line)
878 				break;
879 #else
880 		while (cp->ch == ( wchar_t )btowc(( int )' ' )
881 				&& ( cp->attr & WA_ATTRIBUTES ) == lspc)
882 			if (cp-- <= win->alines[wy]->line)
883 				break;
884 #endif /* HAVE_WCHAR */
885 		if (win->alines[wy]->line > cp)
886 			nlsp = 0;
887 		else
888 			nlsp = cp - win->alines[wy]->line;
889 	}
890 	if (!_cursesi_screen->curwin)
891 		ce = clr_eol;
892 	else
893 		ce = NULL;
894 
895 	while (wx <= lch) {
896 #ifdef DEBUG
897 		__CTRACE(__CTRACE_REFRESH, "makech: wx=%d,lch=%d\n", wx, lch);
898 #endif /* DEBUG */
899 #ifndef HAVE_WCHAR
900 		if (!(wlp->flags & __ISFORCED) &&
901 		    (memcmp(nsp, csp, sizeof(__LDATA)) == 0))
902 		{
903 			if (wx <= lch) {
904 				while (wx <= lch &&
905 				    memcmp(nsp, csp, sizeof(__LDATA)) == 0)
906 				{
907 					nsp++;
908 					if (!_cursesi_screen->curwin)
909 						++csp;
910 					++wx;
911 				}
912 				continue;
913 			}
914 			break;
915 		}
916 #else
917 #ifdef DEBUG
918 		__CTRACE(__CTRACE_REFRESH, "makech: nsp=(%x,%x,%x,%x,%p)\n",
919 			nsp->ch, nsp->attr, win->bch, win->battr, nsp->nsp);
920 		__CTRACE(__CTRACE_REFRESH, "makech: csp=(%x,%x,%x,%x,%p)\n",
921 			csp->ch, csp->attr, win->bch, win->battr, csp->nsp);
922 #endif /* DEBUG */
923 		if (!(wlp->flags & __ISFORCED) &&
924 		     (((nsp->attr & __WCWIDTH) != __WCWIDTH) &&
925 		       cellcmp(nsp, csp)))
926 		{
927 			if (wx <= lch) {
928 				while (wx <= lch && cellcmp( csp, nsp )) {
929 					nsp++;
930 					if (!_cursesi_screen->curwin)
931 						++csp;
932 					++wx;
933 				}
934 				continue;
935 			}
936 			break;
937 		}
938 #endif /* HAVE_WCHAR */
939 		domvcur(win, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
940 
941 #ifdef DEBUG
942 		__CTRACE(__CTRACE_REFRESH, "makech: 1: wx = %d, ly= %d, "
943 		    "lx = %d, newy = %d, newx = %d\n",
944 		    wx, _cursesi_screen->ly, _cursesi_screen->lx, wy, wx);
945 #endif
946 		_cursesi_screen->ly = wy;
947 		_cursesi_screen->lx = wx;
948 #ifndef HAVE_WCHAR
949 		while (wx <= lch && (memcmp(nsp, csp, sizeof(__LDATA)) != 0) ||
950 			(wlp->flags & __ISFORCED))
951 		{
952 			if (ce != NULL &&
953 			    wx >= nlsp && nsp->ch == ' ' && nsp->attr == lspc)
954 			{
955 #else
956 		while ((!cellcmp(nsp, csp) || (wlp->flags & __ISFORCED)) &&
957 			wx <= lch)
958 		{
959 			if (ce != NULL && wx >= nlsp
960 			   && nsp->ch == (wchar_t)btowc((int)' ') /* XXX */
961 			   && (nsp->attr & WA_ATTRIBUTES) == lspc)
962 			{
963 
964 #endif
965 				/* Check for clear to end-of-line. */
966 				cep = &curscr->alines[wy]->line[win->maxx - 1];
967 #ifndef HAVE_WCHAR
968 				while (cep->ch == ' ' && cep->attr == lspc) /* XXX */
969 #else
970 				while (cep->ch == (wchar_t)btowc((int)' ')
971 				       && (cep->attr & WA_ATTRIBUTES) == lspc)
972 #endif /* HAVE_WCHAR */
973 					if (cep-- <= csp)
974 						break;
975 				if (cep > (curscr->alines[wy]->line + win->begx * __LDATASIZE))
976 					clsp = cep - curscr->alines[wy]->line -
977 					win->begx * __LDATASIZE;
978 				else
979 					clsp = 0;
980 #ifdef DEBUG
981 				__CTRACE(__CTRACE_REFRESH,
982 				    "makech: clsp = %zu, nlsp = %zu\n",
983 				    clsp, nlsp);
984 				__CTRACE(__CTRACE_REFRESH,
985 				    "makech: line = %p, cep = %p, begx = %u\n",
986 				    curscr->alines[wy]->line, cep, win->begx);
987 #endif
988 				if (((clsp - nlsp >= strlen(ce) &&
989 				    clsp < win->maxx * __LDATASIZE) ||
990 				    wy == win->maxy - 1) &&
991 				    (!(lspc & __COLOR) ||
992 				    ((lspc & __COLOR) && back_color_erase)))
993 				{
994 					__unsetattr(0);
995 					if (__using_color &&
996 					    ((lspc & __COLOR) !=
997 					    (curscr->wattr & __COLOR)))
998 						__set_color(curscr, lspc &
999 						    __COLOR);
1000 					tputs(ce, 0, __cputchar);
1001 					_cursesi_screen->lx = wx + win->begx;
1002 					while (wx++ <= clsp) {
1003 						csp->attr = lspc;
1004 #ifndef HAVE_WCHAR
1005 						csp->ch = ' '; /* XXX */
1006 #else
1007 						csp->ch = (wchar_t)btowc((int)' ');
1008 						SET_WCOL( *csp, 1 );
1009 #endif /* HAVE_WCHAR */
1010 						csp++;
1011 					}
1012 					return OK;
1013 				}
1014 				ce = NULL;
1015 			}
1016 
1017 #ifdef DEBUG
1018 				__CTRACE(__CTRACE_REFRESH,
1019 				    "makech: have attr %08x, need attr %08x\n",
1020 				    curscr->wattr
1021 #ifndef HAVE_WCHAR
1022 				 & __ATTRIBUTES
1023 #else
1024 				 & WA_ATTRIBUTES
1025 #endif
1026 					 ,  nsp->attr
1027 #ifndef HAVE_WCHAR
1028 				 & __ATTRIBUTES
1029 #else
1030 				 & WA_ATTRIBUTES
1031 #endif
1032 					);
1033 #endif
1034 
1035 			off = (~nsp->attr & curscr->wattr)
1036 #ifndef HAVE_WCHAR
1037 				 & __ATTRIBUTES
1038 #else
1039 				 & WA_ATTRIBUTES
1040 #endif
1041 				;
1042 
1043 			/*
1044 			 * Unset attributes as appropriate.  Unset first
1045 			 * so that the relevant attributes can be reset
1046 			 * (because 'me' unsets 'mb', 'md', 'mh', 'mk',
1047 			 * 'mp' and 'mr').  Check to see if we also turn off
1048 			 * standout, attributes and colour.
1049 			 */
1050 			if (off & __TERMATTR && exit_attribute_mode != NULL) {
1051 				tputs(exit_attribute_mode, 0, __cputchar);
1052 				curscr->wattr &= __mask_me;
1053 				off &= __mask_me;
1054 			}
1055 
1056 			/*
1057 			 * Exit underscore mode if appropriate.
1058 			 * Check to see if we also turn off standout,
1059 			 * attributes and colour.
1060 			 */
1061 			if (off & __UNDERSCORE && exit_underline_mode != NULL) {
1062 				tputs(exit_underline_mode, 0, __cputchar);
1063 				curscr->wattr &= __mask_ue;
1064 				off &= __mask_ue;
1065 			}
1066 
1067 			/*
1068 			 * Exit standout mode as appropriate.
1069 			 * Check to see if we also turn off underscore,
1070 			 * attributes and colour.
1071 			 * XXX
1072 			 * Should use uc if so/se not available.
1073 			 */
1074 			if (off & __STANDOUT && exit_standout_mode != NULL) {
1075 				tputs(exit_standout_mode, 0, __cputchar);
1076 				curscr->wattr &= __mask_se;
1077 				off &= __mask_se;
1078 			}
1079 
1080 			if (off & __ALTCHARSET && exit_alt_charset_mode != NULL) {
1081 				tputs(exit_alt_charset_mode, 0, __cputchar);
1082 				curscr->wattr &= ~__ALTCHARSET;
1083 			}
1084 
1085 			/* Set/change colour as appropriate. */
1086 			if (__using_color)
1087 				__set_color(curscr, nsp->attr & __COLOR);
1088 
1089 			on = (nsp->attr & ~curscr->wattr)
1090 #ifndef HAVE_WCHAR
1091 				 & __ATTRIBUTES
1092 #else
1093 				 & WA_ATTRIBUTES
1094 #endif
1095 				 ;
1096 
1097 			/*
1098 			 * Enter standout mode if appropriate.
1099 			 */
1100 			if (on & __STANDOUT &&
1101 			    enter_standout_mode != NULL &&
1102 			    exit_standout_mode != NULL)
1103 			{
1104 				tputs(enter_standout_mode, 0, __cputchar);
1105 				curscr->wattr |= __STANDOUT;
1106 			}
1107 
1108 			/*
1109 			 * Enter underscore mode if appropriate.
1110 			 * XXX
1111 			 * Should use uc if us/ue not available.
1112 			 */
1113 			if (on & __UNDERSCORE &&
1114 			    enter_underline_mode != NULL &&
1115 			    exit_underline_mode != NULL)
1116 			{
1117 				tputs(enter_underline_mode, 0, __cputchar);
1118 				curscr->wattr |= __UNDERSCORE;
1119 			}
1120 
1121 			/*
1122 			 * Set other attributes as appropriate.
1123 			 */
1124 			if (exit_attribute_mode != NULL) {
1125 				if (on & __BLINK &&
1126 				    enter_blink_mode != NULL)
1127 				{
1128 					tputs(enter_blink_mode, 0, __cputchar);
1129 					curscr->wattr |= __BLINK;
1130 				}
1131 				if (on & __BOLD &&
1132 				    enter_bold_mode != NULL)
1133 				{
1134 					tputs(enter_bold_mode, 0, __cputchar);
1135 					curscr->wattr |= __BOLD;
1136 				}
1137 				if (on & __DIM &&
1138 				    enter_dim_mode != NULL)
1139 				{
1140 					tputs(enter_dim_mode, 0, __cputchar);
1141 					curscr->wattr |= __DIM;
1142 				}
1143 				if (on & __BLANK &&
1144 				    enter_secure_mode != NULL)
1145 				{
1146 					tputs(enter_secure_mode, 0, __cputchar);
1147 					curscr->wattr |= __BLANK;
1148 				}
1149 				if (on & __PROTECT &&
1150 				    enter_protected_mode != NULL)
1151 				{
1152 					tputs(enter_protected_mode, 0, __cputchar);
1153 					curscr->wattr |= __PROTECT;
1154 				}
1155 				if (on & __REVERSE &&
1156 				    enter_reverse_mode != NULL)
1157 				{
1158 					tputs(enter_reverse_mode, 0, __cputchar);
1159 					curscr->wattr |= __REVERSE;
1160 				}
1161 #ifdef HAVE_WCHAR
1162 				if (on & WA_TOP &&
1163 				    enter_top_hl_mode != NULL)
1164 				{
1165 					tputs(enter_top_hl_mode, 0, __cputchar);
1166 					curscr->wattr |= WA_TOP;
1167 				}
1168 				if (on & WA_LOW &&
1169 				    enter_low_hl_mode != NULL)
1170 				{
1171 					tputs(enter_low_hl_mode, 0, __cputchar);
1172 					curscr->wattr |= WA_LOW;
1173 				}
1174 				if (on & WA_LEFT &&
1175 				    enter_left_hl_mode != NULL)
1176 				{
1177 					tputs(enter_left_hl_mode, 0, __cputchar);
1178 					curscr->wattr |= WA_LEFT;
1179 				}
1180 				if (on & WA_RIGHT &&
1181 				    enter_right_hl_mode != NULL)
1182 				{
1183 					tputs(enter_right_hl_mode, 0, __cputchar);
1184 					curscr->wattr |= WA_RIGHT;
1185 				}
1186 				if (on & WA_HORIZONTAL &&
1187 				    enter_horizontal_hl_mode != NULL)
1188 				{
1189 					tputs(enter_horizontal_hl_mode, 0, __cputchar);
1190 					curscr->wattr |= WA_HORIZONTAL;
1191 				}
1192 				if (on & WA_VERTICAL &&
1193 				    enter_vertical_hl_mode != NULL)
1194 				{
1195 					tputs(enter_vertical_hl_mode, 0, __cputchar);
1196 					curscr->wattr |= WA_VERTICAL;
1197 				}
1198 #endif /* HAVE_WCHAR */
1199 			}
1200 
1201 			/* Enter/exit altcharset mode as appropriate. */
1202 			if (on & __ALTCHARSET && enter_alt_charset_mode != NULL &&
1203 			    exit_alt_charset_mode != NULL) {
1204 				tputs(enter_alt_charset_mode, 0, __cputchar);
1205 				curscr->wattr |= __ALTCHARSET;
1206 			}
1207 
1208 			wx++;
1209 			if (wx >= win->maxx &&
1210 			    wy == win->maxy - 1 && !_cursesi_screen->curwin) {
1211 				if (win->flags & __SCROLLOK) {
1212 					if (win->flags & __ENDLINE)
1213 						__unsetattr(1);
1214 					if (!(win->flags & __SCROLLWIN)) {
1215 						if (!_cursesi_screen->curwin) {
1216 							csp->attr = nsp->attr;
1217 							csp->ch = nsp->ch;
1218 #ifdef HAVE_WCHAR
1219 							if (_cursesi_copy_nsp(nsp->nsp, csp) == ERR)
1220 								return ERR;
1221 #endif /* HAVE_WCHAR */
1222 						}
1223 #ifndef HAVE_WCHAR
1224 						__cputchar((int) nsp->ch);
1225 #else
1226 						if ( WCOL( *nsp ) > 0 ) {
1227 							__cputwchar((int)nsp->ch);
1228 #ifdef DEBUG
1229 							__CTRACE(__CTRACE_REFRESH,
1230 							    "makech: (%d,%d)putwchar(0x%x)\n",
1231 								wy, wx - 1,
1232 								nsp->ch );
1233 #endif /* DEBUG */
1234 							/*
1235 							 * Output non-spacing
1236 							 * characters for the
1237 							 * cell.
1238 							 */
1239 							__cursesi_putnsp(nsp->nsp,
1240 									 wy, wx);
1241 
1242 						}
1243 #endif /* HAVE_WCHAR */
1244 					}
1245 					if (wx < curscr->maxx) {
1246 						domvcur(win,
1247 						    _cursesi_screen->ly, wx,
1248 						    (int)(win->maxy - 1),
1249 						    (int)(win->maxx - 1));
1250 					}
1251 					_cursesi_screen->ly = win->maxy - 1;
1252 					_cursesi_screen->lx = win->maxx - 1;
1253 					return (OK);
1254 				}
1255 			}
1256 			if (wx < win->maxx || wy < win->maxy - 1 ||
1257 			    !(win->flags & __SCROLLWIN))
1258 			{
1259 				if (!_cursesi_screen->curwin) {
1260 					csp->attr = nsp->attr;
1261 					csp->ch = nsp->ch;
1262 #ifdef HAVE_WCHAR
1263 					if (_cursesi_copy_nsp(nsp->nsp,
1264 							      csp) == ERR)
1265 						return ERR;
1266 #endif /* HAVE_WCHAR */
1267 					csp++;
1268 				}
1269 #ifndef HAVE_WCHAR
1270 				__cputchar((int)nsp->ch);
1271 #ifdef DEBUG
1272 				__CTRACE(__CTRACE_REFRESH,
1273 				    "makech: putchar(%c)\n", nsp->ch & 0177);
1274 #endif
1275 #else
1276 				if (WCOL(*nsp) > 0) {
1277 					__cputwchar((int)nsp->ch);
1278 #ifdef DEBUG
1279 					__CTRACE(__CTRACE_REFRESH,
1280 					    "makech:(%d,%d) putwchar(%x)\n",
1281 					    wy, wx - 1, nsp->ch);
1282 					__cursesi_putnsp(nsp->nsp, wy, wx);
1283 #endif /* DEBUG */
1284 				}
1285 #endif /* HAVE_WCHAR */
1286 			}
1287 			if (underline_char && ((nsp->attr & __STANDOUT) ||
1288 			    (nsp->attr & __UNDERSCORE))) {
1289 				__cputchar('\b');
1290 				tputs(underline_char, 0, __cputchar);
1291 			}
1292 			nsp++;
1293 #ifdef DEBUG
1294 			__CTRACE(__CTRACE_REFRESH,
1295 			    "makech: 2: wx = %d, lx = %d\n",
1296 			    wx, _cursesi_screen->lx);
1297 #endif
1298 		}
1299 		if (_cursesi_screen->lx == wx)	/* If no change. */
1300 			break;
1301 		_cursesi_screen->lx = wx;
1302 		if (_cursesi_screen->lx >= COLS && auto_right_margin)
1303 			_cursesi_screen->lx = COLS - 1;
1304 		else
1305 			if (wx >= win->maxx) {
1306 				domvcur(win,
1307 					_cursesi_screen->ly,
1308 					_cursesi_screen->lx,
1309 					_cursesi_screen->ly,
1310 					(int)(win->maxx - 1));
1311 				_cursesi_screen->lx = win->maxx - 1;
1312 			}
1313 #ifdef DEBUG
1314 		__CTRACE(__CTRACE_REFRESH, "makech: 3: wx = %d, lx = %d\n",
1315 		    wx, _cursesi_screen->lx);
1316 #endif
1317 	}
1318 #ifdef DEBUG
1319 #if HAVE_WCHAR
1320 	{
1321 		int x;
1322 		__LDATA *lp, *vlp;
1323 
1324 		__CTRACE(__CTRACE_REFRESH,
1325 		    "makech-after: curscr(%p)-__virtscr(%p)\n",
1326 		    curscr, __virtscr );
1327 		for (x = 0; x < curscr->maxx; x++) {
1328 			lp = &curscr->alines[wy]->line[x];
1329 			vlp = &__virtscr->alines[wy]->line[x];
1330 			__CTRACE(__CTRACE_REFRESH,
1331 			    "[%d,%d](%x,%x,%x,%x,%p)-"
1332 			    "(%x,%x,%x,%x,%p)\n",
1333 			    wy, x, lp->ch, lp->attr,
1334 			    win->bch, win->battr, lp->nsp,
1335 			    vlp->ch, vlp->attr,
1336 			    win->bch, win->battr, vlp->nsp);
1337 		}
1338 	}
1339 #endif /* HAVE_WCHAR */
1340 #endif /* DEBUG */
1341 
1342 	return OK;
1343 }
1344 
1345 /*
1346  * domvcur --
1347  *	Do a mvcur, leaving attributes if necessary.
1348  */
1349 static void
1350 domvcur(const WINDOW *win, int oy, int ox, int ny, int nx)
1351 {
1352 
1353 #ifdef DEBUG
1354 	__CTRACE(__CTRACE_REFRESH, "domvcur: (%x,%d)=>(%d,%d)\n",
1355 	    oy, ox, ny, nx );
1356 #endif /* DEBUG */
1357 
1358 	__unsetattr(1);
1359 
1360 	/* Don't move the cursor unless we need to. */
1361 	if (oy == ny && ox == nx) {
1362 		/* Check EOL. */
1363 		if (!(win->alines[oy]->flags & __ISPASTEOL))
1364 			return;
1365 	}
1366 
1367 	/* Clear EOL flags. */
1368 	win->alines[oy]->flags &= ~__ISPASTEOL;
1369 	win->alines[ny]->flags &= ~__ISPASTEOL;
1370 
1371 	__mvcur(oy, ox, ny, nx, 1);
1372 }
1373 
1374 /*
1375  * Quickch() attempts to detect a pattern in the change of the window
1376  * in order to optimize the change, e.g., scroll n lines as opposed to
1377  * repainting the screen line by line.
1378  */
1379 
1380 static __LDATA buf[128];
1381 static  unsigned int last_hash;
1382 static  size_t last_hash_len;
1383 #define BLANKSIZE (sizeof(buf) / sizeof(buf[0]))
1384 
1385 static void
1386 quickch(void)
1387 {
1388 #define THRESH		(int) __virtscr->maxy / 4
1389 
1390 	__LINE *clp, *tmp1, *tmp2;
1391 	int	bsize, curs, curw, starts, startw, i, j;
1392 	int	n, target, cur_period, bot, top, sc_region;
1393 	unsigned int	blank_hash;
1394 	attr_t	bcolor;
1395 
1396 #ifdef __GNUC__
1397 	curs = curw = starts = startw = 0;	/* XXX gcc -Wuninitialized */
1398 #endif
1399 	/*
1400 	 * Find how many lines from the top of the screen are unchanged.
1401 	 */
1402 	for (top = 0; top < __virtscr->maxy; top++) {
1403 #ifndef HAVE_WCHAR
1404 		if (__virtscr->alines[top]->flags & __ISDIRTY &&
1405 		    (__virtscr->alines[top]->hash != curscr->alines[top]->hash ||
1406 		    memcmp(__virtscr->alines[top]->line,
1407 		    curscr->alines[top]->line,
1408 		    (size_t) __virtscr->maxx * __LDATASIZE)
1409 		    != 0))
1410 			break;
1411 #else
1412 		if (__virtscr->alines[top]->flags & __ISDIRTY &&
1413 		    (__virtscr->alines[top]->hash != curscr->alines[top]->hash ||
1414 		    !linecmp(__virtscr->alines[top]->line,
1415 		    curscr->alines[top]->line,
1416 	(size_t) __virtscr->maxx )))
1417 			break;
1418 #endif /* HAVE_WCHAR */
1419 		else
1420 			__virtscr->alines[top]->flags &= ~__ISDIRTY;
1421 	}
1422 	/*
1423 	 * Find how many lines from bottom of screen are unchanged.
1424 	 */
1425 	for (bot = __virtscr->maxy - 1; bot >= 0; bot--) {
1426 #ifndef HAVE_WCHAR
1427 		if (__virtscr->alines[bot]->flags & __ISDIRTY &&
1428 		    (__virtscr->alines[bot]->hash != curscr->alines[bot]->hash ||
1429 		    memcmp(__virtscr->alines[bot]->line,
1430 		    curscr->alines[bot]->line,
1431 		    (size_t) __virtscr->maxx * __LDATASIZE)
1432 		    != 0))
1433 			break;
1434 #else
1435 		if (__virtscr->alines[bot]->flags & __ISDIRTY &&
1436 		    (__virtscr->alines[bot]->hash != curscr->alines[bot]->hash ||
1437 		    !linecmp(__virtscr->alines[bot]->line,
1438 		    curscr->alines[bot]->line,
1439 		    (size_t) __virtscr->maxx )))
1440 			break;
1441 #endif /* HAVE_WCHAR */
1442 		else
1443 			__virtscr->alines[bot]->flags &= ~__ISDIRTY;
1444 	}
1445 
1446 	/*
1447 	 * Work round an xterm bug where inserting lines causes all the
1448 	 * inserted lines to be covered with the background colour we
1449 	 * set on the first line (even if we unset it for subsequent
1450 	 * lines).
1451 	 */
1452 	bcolor = __virtscr->alines[min(top,
1453 	    __virtscr->maxy - 1)]->line[0].attr & __COLOR;
1454 	for (i = top + 1, j = 0; i < bot; i++) {
1455 		if ((__virtscr->alines[i]->line[0].attr & __COLOR) != bcolor) {
1456 			bcolor = __virtscr->alines[i]->line[__virtscr->maxx].
1457 			    attr & __COLOR;
1458 			j = i - top;
1459 		} else
1460 			break;
1461 	}
1462 	top += j;
1463 
1464 #ifdef NO_JERKINESS
1465 	/*
1466 	 * If we have a bottom unchanged region return.  Scrolling the
1467 	 * bottom region up and then back down causes a screen jitter.
1468 	 * This will increase the number of characters sent to the screen
1469 	 * but it looks better.
1470 	 */
1471 	if (bot < __virtscr->maxy - 1)
1472 		return;
1473 #endif				/* NO_JERKINESS */
1474 
1475 	/*
1476 	 * Search for the largest block of text not changed.
1477 	 * Invariants of the loop:
1478 	 * - Startw is the index of the beginning of the examined block in
1479 	 *   __virtscr.
1480 	 * - Starts is the index of the beginning of the examined block in
1481 	 *   curscr.
1482 	 * - Curw is the index of one past the end of the exmined block in
1483 	 *   __virtscr.
1484 	 * - Curs is the index of one past the end of the exmined block in
1485 	 *   curscr.
1486 	 * - bsize is the current size of the examined block.
1487 	*/
1488 
1489 	for (bsize = bot - top; bsize >= THRESH; bsize--) {
1490 		for (startw = top; startw <= bot - bsize; startw++)
1491 			for (starts = top; starts <= bot - bsize; starts++) {
1492 				for (curw = startw, curs = starts;
1493 				    curs < starts + bsize; curw++, curs++)
1494 					if (__virtscr->alines[curw]->hash !=
1495 					    curscr->alines[curs]->hash)
1496 						break;
1497 				if (curs != starts + bsize)
1498 					continue;
1499 				for (curw = startw, curs = starts;
1500 					curs < starts + bsize; curw++, curs++)
1501 #ifndef HAVE_WCHAR
1502 					if (memcmp(__virtscr->alines[curw]->line,
1503 					    curscr->alines[curs]->line,
1504 					    (size_t) __virtscr->maxx *
1505 					    __LDATASIZE) != 0)
1506 						break;
1507 #else
1508 					if (!linecmp(__virtscr->alines[curw]->line,
1509 					    curscr->alines[curs]->line,
1510 					    (size_t) __virtscr->maxx))
1511 						break;
1512 #endif /* HAVE_WCHAR */
1513 				if (curs == starts + bsize)
1514 					goto done;
1515 			}
1516 	}
1517 done:
1518 
1519 	/* Did not find anything */
1520 	if (bsize < THRESH)
1521 		return;
1522 
1523 #ifdef DEBUG
1524 	__CTRACE(__CTRACE_REFRESH, "quickch:bsize=%d, starts=%d, startw=%d, "
1525 	    "curw=%d, curs=%d, top=%d, bot=%d\n",
1526 	    bsize, starts, startw, curw, curs, top, bot);
1527 #endif
1528 
1529 	/*
1530 	 * Make sure that there is no overlap between the bottom and top
1531 	 * regions and the middle scrolled block.
1532 	 */
1533 	if (bot < curs)
1534 		bot = curs - 1;
1535 	if (top > starts)
1536 		top = starts;
1537 
1538 	n = startw - starts;
1539 
1540 #ifdef DEBUG
1541 	__CTRACE(__CTRACE_REFRESH, "#####################################\n");
1542 	for (i = 0; i < curscr->maxy; i++) {
1543 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1544 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n", curscr->alines[i]->hash);
1545 		for (j = 0; j < curscr->maxx; j++)
1546 			__CTRACE(__CTRACE_REFRESH, "%c",
1547 			    curscr->alines[i]->line[j].ch);
1548 		__CTRACE(__CTRACE_REFRESH, "\n");
1549 		__CTRACE(__CTRACE_REFRESH, " attr:");
1550 		for (j = 0; j < curscr->maxx; j++)
1551 			__CTRACE(__CTRACE_REFRESH, " %x",
1552 			    curscr->alines[i]->line[j].attr);
1553 		__CTRACE(__CTRACE_REFRESH, "\n");
1554 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1555 		__CTRACE(__CTRACE_REFRESH, " 0x%x \n",
1556 		    __virtscr->alines[i]->hash);
1557 		__CTRACE(__CTRACE_REFRESH, " 0x%x ",
1558 		    __virtscr->alines[i]->flags);
1559 		for (j = 0; j < __virtscr->maxx; j++)
1560 			__CTRACE(__CTRACE_REFRESH, "%c",
1561 			    __virtscr->alines[i]->line[j].ch);
1562 		__CTRACE(__CTRACE_REFRESH, "\n");
1563 		__CTRACE(__CTRACE_REFRESH, " attr:");
1564 		for (j = 0; j < __virtscr->maxx; j++)
1565 			__CTRACE(__CTRACE_REFRESH, " %x",
1566 			    __virtscr->alines[i]->line[j].attr);
1567 		__CTRACE(__CTRACE_REFRESH, "\n");
1568 	}
1569 #endif
1570 
1571 #ifndef HAVE_WCHAR
1572 	if (buf[0].ch != ' ') {
1573 		for (i = 0; i < BLANKSIZE; i++) {
1574 			buf[i].ch = ' ';
1575 			buf[i].attr = 0;
1576 		}
1577 	}
1578 #else
1579 	if (buf[0].ch != (wchar_t)btowc((int)curscr->bch )) {
1580 		for (i = 0; i < BLANKSIZE; i++) {
1581 			buf[i].ch = (wchar_t)btowc((int)curscr->bch);
1582 			if (_cursesi_copy_nsp(curscr->bnsp, &buf[i]) == ERR)
1583 				return;
1584 			buf[i].attr = 0;
1585 			SET_WCOL(buf[i], 1);
1586 		}
1587 	}
1588 #endif /* HAVE_WCHAR */
1589 
1590 	if (__virtscr->maxx != last_hash_len) {
1591 		blank_hash = 0;
1592 		for (i = __virtscr->maxx; i > BLANKSIZE; i -= BLANKSIZE) {
1593 			blank_hash = __hash_more(buf, sizeof(buf), blank_hash);
1594 		}
1595 		blank_hash = __hash_more((char *)(void *)buf,
1596 		    i * sizeof(buf[0]), blank_hash);
1597 		/* cache result in static data - screen width doesn't change often */
1598 		last_hash_len = __virtscr->maxx;
1599 		last_hash = blank_hash;
1600 	} else
1601 		blank_hash = last_hash;
1602 
1603 	/*
1604 	 * Perform the rotation to maintain the consistency of curscr.
1605 	 * This is hairy since we are doing an *in place* rotation.
1606 	 * Invariants of the loop:
1607 	 * - I is the index of the current line.
1608 	 * - Target is the index of the target of line i.
1609 	 * - Tmp1 points to current line (i).
1610 	 * - Tmp2 and points to target line (target);
1611 	 * - Cur_period is the index of the end of the current period.
1612 	 *   (see below).
1613 	 *
1614 	 * There are 2 major issues here that make this rotation non-trivial:
1615 	 * 1.  Scrolling in a scrolling region bounded by the top
1616 	 *     and bottom regions determined (whose size is sc_region).
1617 	 * 2.  As a result of the use of the mod function, there may be a
1618 	 *     period introduced, i.e., 2 maps to 4, 4 to 6, n-2 to 0, and
1619 	 *     0 to 2, which then causes all odd lines not to be rotated.
1620 	 *     To remedy this, an index of the end ( = beginning) of the
1621 	 *     current 'period' is kept, cur_period, and when it is reached,
1622 	 *     the next period is started from cur_period + 1 which is
1623 	 *     guaranteed not to have been reached since that would mean that
1624 	 *     all records would have been reached. (think about it...).
1625 	 *
1626 	 * Lines in the rotation can have 3 attributes which are marked on the
1627 	 * line so that curscr is consistent with the visual screen.
1628 	 * 1.  Not dirty -- lines inside the scrolled block, top region or
1629 	 *                  bottom region.
1630 	 * 2.  Blank lines -- lines in the differential of the scrolling
1631 	 *		      region adjacent to top and bot regions
1632 	 *                    depending on scrolling direction.
1633 	 * 3.  Dirty line -- all other lines are marked dirty.
1634 	 */
1635 	sc_region = bot - top + 1;
1636 	i = top;
1637 	tmp1 = curscr->alines[top];
1638 	cur_period = top;
1639 	for (j = top; j <= bot; j++) {
1640 		target = (i - top + n + sc_region) % sc_region + top;
1641 		tmp2 = curscr->alines[target];
1642 		curscr->alines[target] = tmp1;
1643 		/* Mark block as clean and blank out scrolled lines. */
1644 		clp = curscr->alines[target];
1645 #ifdef DEBUG
1646 		__CTRACE(__CTRACE_REFRESH,
1647 		    "quickch: n=%d startw=%d curw=%d i = %d target=%d ",
1648 		    n, startw, curw, i, target);
1649 #endif
1650 		if ((target >= startw && target < curw) || target < top
1651 		    || target > bot)
1652 		{
1653 #ifdef DEBUG
1654 			__CTRACE(__CTRACE_REFRESH, " notdirty\n");
1655 #endif
1656 			__virtscr->alines[target]->flags &= ~__ISDIRTY;
1657 		} else
1658 			if ((n > 0 && target >= top && target < top + n) ||
1659 			    (n < 0 && target <= bot && target > bot + n))
1660 			{
1661 #ifndef HAVE_WCHAR
1662 				if (clp->hash != blank_hash ||
1663 				    memcmp(clp->line, clp->line + 1,
1664 				    (__virtscr->maxx - 1)
1665 				    * __LDATASIZE) ||
1666 				    memcmp(clp->line, buf, __LDATASIZE))
1667 				{
1668 #else
1669 				if (clp->hash != blank_hash
1670 				    || linecmp(clp->line, clp->line + 1,
1671 				    (unsigned int) (__virtscr->maxx - 1))
1672 				    || cellcmp(clp->line, buf))
1673 				{
1674 #endif /* HAVE_WCHAR */
1675 					for (i = __virtscr->maxx;
1676 					    i > BLANKSIZE;
1677 					    i -= BLANKSIZE) {
1678 						(void) memcpy(clp->line + i -
1679 						    BLANKSIZE, buf, sizeof(buf));
1680 					}
1681 					(void) memcpy(clp->line , buf, i *
1682 					    sizeof(buf[0]));
1683 #ifdef DEBUG
1684 					__CTRACE(__CTRACE_REFRESH,
1685 					    " blanked out: dirty\n");
1686 #endif
1687 					clp->hash = blank_hash;
1688 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1689 				} else {
1690 #ifdef DEBUG
1691 					__CTRACE(__CTRACE_REFRESH,
1692 					    " -- blank line already: dirty\n");
1693 #endif
1694 					__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1695 				}
1696 			} else {
1697 #ifdef DEBUG
1698 				__CTRACE(__CTRACE_REFRESH, " -- dirty\n");
1699 #endif
1700 				__touchline(__virtscr, target, 0, (int) __virtscr->maxx - 1);
1701 			}
1702 		if (target == cur_period) {
1703 			i = target + 1;
1704 			tmp1 = curscr->alines[i];
1705 			cur_period = i;
1706 		} else {
1707 			tmp1 = tmp2;
1708 			i = target;
1709 		}
1710 	}
1711 #ifdef DEBUG
1712 	__CTRACE(__CTRACE_REFRESH, "$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
1713 	for (i = 0; i < curscr->maxy; i++) {
1714 		__CTRACE(__CTRACE_REFRESH, "C: %d:", i);
1715 		for (j = 0; j < curscr->maxx; j++)
1716 			__CTRACE(__CTRACE_REFRESH, "%c",
1717 			    curscr->alines[i]->line[j].ch);
1718 		__CTRACE(__CTRACE_REFRESH, "\n");
1719 		__CTRACE(__CTRACE_REFRESH, "W: %d:", i);
1720 		for (j = 0; j < __virtscr->maxx; j++)
1721 			__CTRACE(__CTRACE_REFRESH, "%c",
1722 			    __virtscr->alines[i]->line[j].ch);
1723 		__CTRACE(__CTRACE_REFRESH, "\n");
1724 	}
1725 #endif
1726 	if (n != 0)
1727 		scrolln(starts, startw, curs, bot, top);
1728 }
1729 
1730 /*
1731  * scrolln --
1732  *	Scroll n lines, where n is starts - startw.
1733  */
1734 static void /* ARGSUSED */
1735 scrolln(int starts, int startw, int curs, int bot, int top)
1736 {
1737 	int	i, oy, ox, n;
1738 
1739 	oy = curscr->cury;
1740 	ox = curscr->curx;
1741 	n = starts - startw;
1742 
1743 	/*
1744 	 * XXX
1745 	 * The initial tests that set __noqch don't let us reach here unless
1746 	 * we have either cs + ho + SF/sf/SR/sr, or AL + DL.  SF/sf and SR/sr
1747 	 * scrolling can only shift the entire scrolling region, not just a
1748 	 * part of it, which means that the quickch() routine is going to be
1749 	 * sadly disappointed in us if we don't have cs as well.
1750 	 *
1751 	 * If cs, ho and SF/sf are set, can use the scrolling region.  Because
1752 	 * the cursor position after cs is undefined, we need ho which gives us
1753 	 * the ability to move to somewhere without knowledge of the current
1754 	 * location of the cursor.  Still call __mvcur() anyway, to update its
1755 	 * idea of where the cursor is.
1756 	 *
1757 	 * When the scrolling region has been set, the cursor has to be at the
1758 	 * last line of the region to make the scroll happen.
1759 	 *
1760 	 * Doing SF/SR or AL/DL appears faster on the screen than either sf/sr
1761 	 * or AL/DL, and, some terminals have AL/DL, sf/sr, and cs, but not
1762 	 * SF/SR.  So, if we're scrolling almost all of the screen, try and use
1763 	 * AL/DL, otherwise use the scrolling region.  The "almost all" is a
1764 	 * shameless hack for vi.
1765 	 */
1766 	if (n > 0) {
1767 		if (change_scroll_region != NULL && cursor_home != NULL &&
1768 		    (parm_index != NULL ||
1769 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1770 		    top > 3 || bot + 3 < __virtscr->maxy) &&
1771 		    scroll_forward != NULL)))
1772 		{
1773 			tputs(tiparm(change_scroll_region, top, bot),
1774 			    0, __cputchar);
1775 			__mvcur(oy, ox, 0, 0, 1);
1776 			tputs(cursor_home, 0, __cputchar);
1777 			__mvcur(0, 0, bot, 0, 1);
1778 			if (parm_index != NULL)
1779 				tputs(tiparm(parm_index, n),
1780 				    0, __cputchar);
1781 			else
1782 				for (i = 0; i < n; i++)
1783 					tputs(scroll_forward, 0, __cputchar);
1784 			tputs(tiparm(change_scroll_region,
1785 			    0, (int)__virtscr->maxy - 1), 0, __cputchar);
1786 			__mvcur(bot, 0, 0, 0, 1);
1787 			tputs(cursor_home, 0, __cputchar);
1788 			__mvcur(0, 0, oy, ox, 1);
1789 			return;
1790 		}
1791 
1792 		/* Scroll up the block. */
1793 		if (parm_index != NULL && top == 0) {
1794 			__mvcur(oy, ox, bot, 0, 1);
1795 			tputs(tiparm(parm_index, n), 0, __cputchar);
1796 		} else
1797 			if (parm_delete_line != NULL) {
1798 				__mvcur(oy, ox, top, 0, 1);
1799 				tputs(tiparm(parm_delete_line, n),
1800 				    0, __cputchar);
1801 			} else
1802 				if (delete_line != NULL) {
1803 					__mvcur(oy, ox, top, 0, 1);
1804 					for (i = 0; i < n; i++)
1805 						tputs(delete_line, 0,
1806 						    __cputchar);
1807 				} else
1808 					if (scroll_forward != NULL && top == 0) {
1809 						__mvcur(oy, ox, bot, 0, 1);
1810 						for (i = 0; i < n; i++)
1811 							tputs(scroll_forward, 0,
1812 							    __cputchar);
1813 					} else
1814 						abort();
1815 
1816 		/* Push down the bottom region. */
1817 		__mvcur(top, 0, bot - n + 1, 0, 1);
1818 		if (parm_insert_line != NULL)
1819 			tputs(tiparm(parm_insert_line, n), 0, __cputchar);
1820 		else {
1821 			if (insert_line != NULL) {
1822 				for (i = 0; i < n; i++)
1823 					tputs(insert_line, 0, __cputchar);
1824 			} else
1825 				abort();
1826 		}
1827 		__mvcur(bot - n + 1, 0, oy, ox, 1);
1828 	} else {
1829 		/*
1830 		 * !!!
1831 		 * n < 0
1832 		 *
1833 		 * If cs, ho and SR/sr are set, can use the scrolling region.
1834 		 * See the above comments for details.
1835 		 */
1836 		if (change_scroll_region != NULL && cursor_home != NULL &&
1837 		    (parm_rindex != NULL ||
1838 		    ((parm_insert_line == NULL || parm_delete_line == NULL ||
1839 		    top > 3 ||
1840 		    bot + 3 < __virtscr->maxy) && scroll_reverse != NULL)))
1841 		{
1842 			tputs(tiparm(change_scroll_region, top, bot),
1843 			    0, __cputchar);
1844 			__mvcur(oy, ox, 0, 0, 1);
1845 			tputs(cursor_home, 0, __cputchar);
1846 			__mvcur(0, 0, top, 0, 1);
1847 
1848 			if (parm_rindex != NULL)
1849 				tputs(tiparm(parm_rindex, -n),
1850 				    0, __cputchar);
1851 			else
1852 				for (i = n; i < 0; i++)
1853 					tputs(scroll_reverse, 0, __cputchar);
1854 			tputs(tiparm(change_scroll_region,
1855 			    0, (int) __virtscr->maxy - 1), 0, __cputchar);
1856 			__mvcur(top, 0, 0, 0, 1);
1857 			tputs(cursor_home, 0, __cputchar);
1858 			__mvcur(0, 0, oy, ox, 1);
1859 			return;
1860 		}
1861 
1862 		/* Preserve the bottom lines. */
1863 		__mvcur(oy, ox, bot + n + 1, 0, 1);
1864 		if (parm_rindex != NULL && bot == __virtscr->maxy)
1865 			tputs(tiparm(parm_rindex, -n), 0, __cputchar);
1866 		else {
1867 			if (parm_delete_line != NULL)
1868 				tputs(tiparm(parm_delete_line, -n),
1869 				    0, __cputchar);
1870 			else {
1871 				if (delete_line != NULL)
1872 					for (i = n; i < 0; i++)
1873 						tputs(delete_line,
1874 						    0, __cputchar);
1875 				else {
1876 					if (scroll_reverse != NULL &&
1877 					    bot == __virtscr->maxy)
1878 						for (i = n; i < 0; i++)
1879 							tputs(scroll_reverse, 0,
1880 							    __cputchar);
1881 					else
1882 						abort();
1883 				}
1884 			}
1885 		}
1886 		/* Scroll the block down. */
1887 		__mvcur(bot + n + 1, 0, top, 0, 1);
1888 		if (parm_insert_line != NULL)
1889 			tputs(tiparm(parm_insert_line, -n), 0, __cputchar);
1890 		else
1891 			if (insert_line != NULL)
1892 				for (i = n; i < 0; i++)
1893 					tputs(insert_line, 0, __cputchar);
1894 			else
1895 				abort();
1896 		__mvcur(top, 0, oy, ox, 1);
1897 	}
1898 }
1899 
1900 /*
1901  * __unsetattr --
1902  *	Unset attributes on curscr.  Leave standout, attribute and colour
1903  *	modes if necessary (!ms).  Always leave altcharset (xterm at least
1904  *	ignores a cursor move if we don't).
1905  */
1906 void /* ARGSUSED */
1907 __unsetattr(int checkms)
1908 {
1909 	int	isms;
1910 
1911 	if (checkms) {
1912 		if (!move_standout_mode)
1913 			isms = 1;
1914 		else
1915 			isms = 0;
1916 	} else
1917 		isms = 1;
1918 #ifdef DEBUG
1919 	__CTRACE(__CTRACE_REFRESH,
1920 	    "__unsetattr: checkms = %d, ms = %s, wattr = %08x\n",
1921 	    checkms, move_standout_mode ? "TRUE" : "FALSE", curscr->wattr);
1922 #endif
1923 
1924 	/*
1925 	 * Don't leave the screen in standout mode (check against ms).  Check
1926 	 * to see if we also turn off underscore, attributes and colour.
1927 	 */
1928 	if (curscr->wattr & __STANDOUT && isms) {
1929 		tputs(exit_standout_mode, 0, __cputchar);
1930 		curscr->wattr &= __mask_se;
1931 	}
1932 	/*
1933 	 * Don't leave the screen in underscore mode (check against ms).
1934 	 * Check to see if we also turn off attributes.  Assume that we
1935 	 * also turn off colour.
1936 	 */
1937 	if (curscr->wattr & __UNDERSCORE && isms) {
1938 		tputs(exit_underline_mode, 0, __cputchar);
1939 		curscr->wattr &= __mask_ue;
1940 	}
1941 	/*
1942 	 * Don't leave the screen with attributes set (check against ms).
1943 	 * Assume that also turn off colour.
1944 	 */
1945 	if (curscr->wattr & __TERMATTR && isms) {
1946 		tputs(exit_attribute_mode, 0, __cputchar);
1947 		curscr->wattr &= __mask_me;
1948 	}
1949 	/* Don't leave the screen with altcharset set (don't check ms). */
1950 	if (curscr->wattr & __ALTCHARSET) {
1951 		tputs(exit_alt_charset_mode, 0, __cputchar);
1952 		curscr->wattr &= ~__ALTCHARSET;
1953 	}
1954 	/* Don't leave the screen with colour set (check against ms). */
1955 	if (__using_color && isms)
1956 		__unset_color(curscr);
1957 }
1958 
1959 #ifdef HAVE_WCHAR
1960 /* compare two cells on screen, must have the same forground/background,
1961  * and the same sequence of non-spacing characters */
1962 int
1963 cellcmp( __LDATA *x, __LDATA *y )
1964 {
1965 	nschar_t *xnp = x->nsp, *ynp = y->nsp;
1966 	int ret = ( x->ch == y->ch ) & ( x->attr == y->attr );
1967 
1968 	if (!ret)
1969 		return 0;
1970 	if (!xnp && !ynp)
1971 		return 1;
1972 	if ((xnp && !ynp) || (!xnp && ynp))
1973 		return 0;
1974 
1975 	while (xnp && ynp) {
1976 		if (xnp->ch != ynp->ch)
1977 			return 0;
1978 		xnp = xnp->next;
1979 		ynp = ynp->next;
1980 	}
1981 	return !xnp && !ynp;
1982 }
1983 
1984 /* compare two line segments */
1985 int
1986 linecmp( __LDATA *xl, __LDATA *yl, size_t len )
1987 {
1988 	int i = 0;
1989 	__LDATA *xp = xl, *yp = yl;
1990 
1991 	for (i = 0; i < len; i++, xp++, yp++) {
1992 		if (!cellcmp(xp, yp))
1993 			return 0;
1994 	}
1995 	return 1;
1996 }
1997 
1998 /*
1999  * Output the non-spacing characters associated with the given character
2000  * cell to the screen.
2001  */
2002 
2003 void
2004 __cursesi_putnsp(nschar_t *nsp, const int wy, const int wx)
2005 {
2006 	nschar_t *p;
2007 
2008 	/* this shuts up gcc warnings about wx and wy not being used */
2009 	if (wx > wy) {
2010 	}
2011 
2012 	p = nsp;
2013 	while (p != NULL) {
2014 		__cputwchar((int)p->ch);
2015 #ifdef DEBUG
2016 		__CTRACE(__CTRACE_REFRESH,
2017 		       "_cursesi_putnsp: (%d,%d) non-spacing putwchar(0x%x)\n",
2018 			 wy, wx - 1, p->ch);
2019 #endif
2020 		p = p->next;
2021 	}
2022 }
2023 
2024 #endif /* HAVE_WCHAR */
2025