xref: /freebsd/contrib/nvi/vi/v_txt.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*-
2  * Copyright (c) 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/stat.h>
15 
16 #include <bitstring.h>
17 #include <ctype.h>
18 #include <errno.h>
19 #include <limits.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 
25 #include "../common/common.h"
26 #include "vi.h"
27 
28 static int	 txt_abbrev(SCR *, TEXT *, CHAR_T *, int, int *, int *);
29 static void	 txt_ai_resolve(SCR *, TEXT *, int *);
30 static TEXT	*txt_backup(SCR *, TEXTH *, TEXT *, u_int32_t *);
31 static int	 txt_dent(SCR *, TEXT *, int, int);
32 static int	 txt_emark(SCR *, TEXT *, size_t);
33 static void	 txt_err(SCR *, TEXTH *);
34 static int	 txt_fc(SCR *, TEXT *, int *);
35 static int	 txt_fc_col(SCR *, int, ARGS **);
36 static int	 txt_hex(SCR *, TEXT *);
37 static int	 txt_insch(SCR *, TEXT *, CHAR_T *, u_int);
38 static int	 txt_isrch(SCR *, VICMD *, TEXT *, u_int8_t *);
39 static int	 txt_map_end(SCR *);
40 static int	 txt_map_init(SCR *);
41 static int	 txt_margin(SCR *, TEXT *, TEXT *, int *, u_int32_t);
42 static void	 txt_nomorech(SCR *);
43 static void	 txt_Rresolve(SCR *, TEXTH *, TEXT *, const size_t);
44 static int	 txt_resolve(SCR *, TEXTH *, u_int32_t);
45 static int	 txt_showmatch(SCR *, TEXT *);
46 static void	 txt_unmap(SCR *, TEXT *, u_int32_t *);
47 
48 /* Cursor character (space is hard to track on the screen). */
49 #if defined(DEBUG) && 0
50 #undef	CH_CURSOR
51 #define	CH_CURSOR	'+'
52 #endif
53 
54 /*
55  * v_tcmd --
56  *	Fill a buffer from the terminal for vi.
57  *
58  * PUBLIC: int v_tcmd(SCR *, VICMD *, ARG_CHAR_T, u_int);
59  */
60 int
61 v_tcmd(SCR *sp, VICMD *vp, ARG_CHAR_T prompt, u_int flags)
62 {
63 	/* Normally, we end up where we started. */
64 	vp->m_final.lno = sp->lno;
65 	vp->m_final.cno = sp->cno;
66 
67 	/* Initialize the map. */
68 	if (txt_map_init(sp))
69 		return (1);
70 
71 	/* Move to the last line. */
72 	sp->lno = TMAP[0].lno;
73 	sp->cno = 0;
74 
75 	/* Don't update the modeline for now. */
76 	F_SET(sp, SC_TINPUT_INFO);
77 
78 	/* Set the input flags. */
79 	LF_SET(TXT_APPENDEOL |
80 	    TXT_CR | TXT_ESCAPE | TXT_INFOLINE | TXT_MAPINPUT);
81 	if (O_ISSET(sp, O_ALTWERASE))
82 		LF_SET(TXT_ALTWERASE);
83 	if (O_ISSET(sp, O_TTYWERASE))
84 		LF_SET(TXT_TTYWERASE);
85 
86 	/* Do the input thing. */
87 	if (v_txt(sp, vp, NULL, NULL, 0, prompt, 0, 1, flags))
88 		return (1);
89 
90 	/* Reenable the modeline updates. */
91 	F_CLR(sp, SC_TINPUT_INFO);
92 
93 	/* Clean up the map. */
94 	if (txt_map_end(sp))
95 		return (1);
96 
97 	if (IS_ONELINE(sp))
98 		F_SET(sp, SC_SCR_REDRAW);	/* XXX */
99 
100 	/* Set the cursor to the resulting position. */
101 	sp->lno = vp->m_final.lno;
102 	sp->cno = vp->m_final.cno;
103 
104 	return (0);
105 }
106 
107 /*
108  * txt_map_init
109  *	Initialize the screen map for colon command-line input.
110  */
111 static int
112 txt_map_init(SCR *sp)
113 {
114 	SMAP *esmp;
115 	VI_PRIVATE *vip;
116 
117 	vip = VIP(sp);
118 	if (!IS_ONELINE(sp)) {
119 		/*
120 		 * Fake like the user is doing input on the last line of the
121 		 * screen.  This makes all of the scrolling work correctly,
122 		 * and allows us the use of the vi text editing routines, not
123 		 * to mention practically infinite length ex commands.
124 		 *
125 		 * Save the current location.
126 		 */
127 		vip->sv_tm_lno = TMAP->lno;
128 		vip->sv_tm_soff = TMAP->soff;
129 		vip->sv_tm_coff = TMAP->coff;
130 		vip->sv_t_maxrows = sp->t_maxrows;
131 		vip->sv_t_minrows = sp->t_minrows;
132 		vip->sv_t_rows = sp->t_rows;
133 
134 		/*
135 		 * If it's a small screen, TMAP may be small for the screen.
136 		 * Fix it, filling in fake lines as we go.
137 		 */
138 		if (IS_SMALL(sp))
139 			for (esmp =
140 			    HMAP + (sp->t_maxrows - 1); TMAP < esmp; ++TMAP) {
141 				TMAP[1].lno = TMAP[0].lno + 1;
142 				TMAP[1].coff = HMAP->coff;
143 				TMAP[1].soff = 1;
144 			}
145 
146 		/* Build the fake entry. */
147 		TMAP[1].lno = TMAP[0].lno + 1;
148 		TMAP[1].soff = 1;
149 		TMAP[1].coff = 0;
150 		SMAP_FLUSH(&TMAP[1]);
151 		++TMAP;
152 
153 		/* Reset the screen information. */
154 		sp->t_rows = sp->t_minrows = ++sp->t_maxrows;
155 	}
156 	return (0);
157 }
158 
159 /*
160  * txt_map_end
161  *	Reset the screen map for colon command-line input.
162  */
163 static int
164 txt_map_end(SCR *sp)
165 {
166 	VI_PRIVATE *vip;
167 	size_t cnt;
168 
169 	vip = VIP(sp);
170 	if (!IS_ONELINE(sp)) {
171 		/* Restore the screen information. */
172 		sp->t_rows = vip->sv_t_rows;
173 		sp->t_minrows = vip->sv_t_minrows;
174 		sp->t_maxrows = vip->sv_t_maxrows;
175 
176 		/*
177 		 * If it's a small screen, TMAP may be wrong.  Clear any
178 		 * lines that might have been overwritten.
179 		 */
180 		if (IS_SMALL(sp)) {
181 			for (cnt = sp->t_rows; cnt <= sp->t_maxrows; ++cnt) {
182 				(void)sp->gp->scr_move(sp, cnt, 0);
183 				(void)sp->gp->scr_clrtoeol(sp);
184 			}
185 			TMAP = HMAP + (sp->t_rows - 1);
186 		} else
187 			--TMAP;
188 
189 		/*
190 		 * The map may be wrong if the user entered more than one
191 		 * (logical) line.  Fix it.  If the user entered a whole
192 		 * screen, this will be slow, but we probably don't care.
193 		 */
194 		if (!O_ISSET(sp, O_LEFTRIGHT))
195 			while (vip->sv_tm_lno != TMAP->lno ||
196 			    vip->sv_tm_soff != TMAP->soff)
197 				if (vs_sm_1down(sp))
198 					return (1);
199 	}
200 
201 	/*
202 	 * Invalidate the cursor and the line size cache, the line never
203 	 * really existed.  This fixes bugs where the user searches for
204 	 * the last line on the screen + 1 and the refresh routine thinks
205 	 * that's where we just were.
206 	 */
207 	VI_SCR_CFLUSH(vip);
208 	F_SET(vip, VIP_CUR_INVALID);
209 
210 	return (0);
211 }
212 
213 /*
214  * If doing input mapping on the colon command line, may need to unmap
215  * based on the command.
216  */
217 #define	UNMAP_TST							\
218 	FL_ISSET(ec_flags, EC_MAPINPUT) && LF_ISSET(TXT_INFOLINE)
219 
220 /*
221  * Internally, we maintain tp->lno and tp->cno, externally, everyone uses
222  * sp->lno and sp->cno.  Make them consistent as necessary.
223  */
224 #define	UPDATE_POSITION(sp, tp) do {					\
225 	(sp)->lno = (tp)->lno;						\
226 	(sp)->cno = (tp)->cno;						\
227 } while (0)
228 
229 /*
230  * v_txt --
231  *	Vi text input.
232  *
233  * PUBLIC: int v_txt(SCR *, VICMD *, MARK *,
234  * PUBLIC:    const CHAR_T *, size_t, ARG_CHAR_T, recno_t, u_long, u_int32_t);
235  */
236 int
237 v_txt(
238 	SCR *sp,
239 	VICMD *vp,
240 	MARK *tm,		/* To MARK. */
241 	const CHAR_T *lp,	/* Input line. */
242 	size_t len,		/* Input line length. */
243 	ARG_CHAR_T prompt,	/* Prompt to display. */
244 	recno_t ai_line,	/* Line number to use for autoindent count. */
245 	u_long rcount,		/* Replay count. */
246 	u_int32_t flags)	/* TXT_* flags. */
247 {
248 	EVENT ev, *evp = NULL;	/* Current event. */
249 	EVENT fc;		/* File name completion event. */
250 	GS *gp;
251 	TEXT *ntp, *tp;		/* Input text structures. */
252 	TEXT ait;		/* Autoindent text structure. */
253 	TEXT wmt = {{ 0 }};	/* Wrapmargin text structure. */
254 	TEXTH *tiqh;
255 	VI_PRIVATE *vip;
256 	abb_t abb;		/* State of abbreviation checks. */
257 	carat_t carat;		/* State of the "[^0]^D" sequences. */
258 	quote_t quote;		/* State of quotation. */
259 	size_t owrite, insert;	/* Temporary copies of TEXT fields. */
260 	size_t margin;		/* Wrapmargin value. */
261 	size_t rcol;		/* 0-N: insert offset in the replay buffer. */
262 	size_t tcol;		/* Temporary column. */
263 	u_int32_t ec_flags;	/* Input mapping flags. */
264 #define	IS_RESTART	0x01	/* Reset the incremental search. */
265 #define	IS_RUNNING	0x02	/* Incremental search turned on. */
266 	u_int8_t is_flags;
267 	int abcnt, ab_turnoff;	/* Abbreviation character count, switch. */
268 	int filec_redraw;	/* Redraw after the file completion routine. */
269 	int hexcnt;		/* Hex character count. */
270 	int showmatch;		/* Showmatch set on this character. */
271 	int wm_set, wm_skip;	/* Wrapmargin happened, blank skip flags. */
272 	int max, tmp;
273 	int nochange;
274 	CHAR_T *p;
275 
276 	gp = sp->gp;
277 	vip = VIP(sp);
278 
279 	/*
280 	 * Set the input flag, so tabs get displayed correctly
281 	 * and everyone knows that the text buffer is in use.
282 	 */
283 	F_SET(sp, SC_TINPUT);
284 
285 	/*
286 	 * Get one TEXT structure with some initial buffer space, reusing
287 	 * the last one if it's big enough.  (All TEXT bookkeeping fields
288 	 * default to 0 -- text_init() handles this.)  If changing a line,
289 	 * copy it into the TEXT buffer.
290 	 */
291 	tiqh = sp->tiq;
292 	if (!TAILQ_EMPTY(tiqh)) {
293 		tp = TAILQ_FIRST(tiqh);
294 		if (TAILQ_NEXT(tp, q) != NULL ||
295 		    tp->lb_len < (len + 32) * sizeof(CHAR_T)) {
296 			text_lfree(tiqh);
297 			goto newtp;
298 		}
299 		tp->ai = tp->insert = tp->offset = tp->owrite = 0;
300 		if (lp != NULL) {
301 			tp->len = len;
302 			BINC_RETW(sp, tp->lb, tp->lb_len, len);
303 			MEMMOVE(tp->lb, lp, len);
304 		} else
305 			tp->len = 0;
306 	} else {
307 newtp:		if ((tp = text_init(sp, lp, len, len + 32)) == NULL)
308 			return (1);
309 		TAILQ_INSERT_HEAD(tiqh, tp, q);
310 	}
311 
312 	/* Set default termination condition. */
313 	tp->term = TERM_OK;
314 
315 	/* Set the starting line, column. */
316 	tp->lno = sp->lno;
317 	tp->cno = sp->cno;
318 
319 	/*
320 	 * Set the insert and overwrite counts.  If overwriting characters,
321 	 * do insertion afterward.  If not overwriting characters, assume
322 	 * doing insertion.  If change is to a mark, emphasize it with an
323 	 * CH_ENDMARK character.
324 	 */
325 	if (len) {
326 		if (LF_ISSET(TXT_OVERWRITE)) {
327 			tp->owrite = (tm->cno - tp->cno) + 1;
328 			tp->insert = (len - tm->cno) - 1;
329 		} else
330 			tp->insert = len - tp->cno;
331 
332 		if (LF_ISSET(TXT_EMARK) && txt_emark(sp, tp, tm->cno))
333 			return (1);
334 	}
335 
336 	/*
337 	 * Many of the special cases in text input are to handle autoindent
338 	 * support.  Somebody decided that it would be a good idea if "^^D"
339 	 * and "0^D" deleted all of the autoindented characters.  In an editor
340 	 * that takes single character input from the user, this beggars the
341 	 * imagination.  Note also, "^^D" resets the next lines' autoindent,
342 	 * but "0^D" doesn't.
343 	 *
344 	 * We assume that autoindent only happens on empty lines, so insert
345 	 * and overwrite will be zero.  If doing autoindent, figure out how
346 	 * much indentation we need and fill it in.  Update input column and
347 	 * screen cursor as necessary.
348 	 */
349 	if (LF_ISSET(TXT_AUTOINDENT) && ai_line != OOBLNO) {
350 		if (v_txt_auto(sp, ai_line, NULL, 0, tp))
351 			return (1);
352 		tp->cno = tp->ai;
353 	} else {
354 		/*
355 		 * The cc and S commands have a special feature -- leading
356 		 * <blank> characters are handled as autoindent characters.
357 		 * Beauty!
358 		 */
359 		if (LF_ISSET(TXT_AICHARS)) {
360 			tp->offset = 0;
361 			tp->ai = tp->cno;
362 		} else
363 			tp->offset = tp->cno;
364 	}
365 
366 	/* If getting a command buffer from the user, there may be a prompt. */
367 	if (LF_ISSET(TXT_PROMPT)) {
368 		tp->lb[tp->cno++] = prompt;
369 		++tp->len;
370 		++tp->offset;
371 	}
372 
373 	/*
374 	 * If appending after the end-of-line, add a space into the buffer
375 	 * and move the cursor right.  This space is inserted, i.e. pushed
376 	 * along, and then deleted when the line is resolved.  Assumes that
377 	 * the cursor is already positioned at the end of the line.  This
378 	 * avoids the nastiness of having the cursor reside on a magical
379 	 * column, i.e. a column that doesn't really exist.  The only down
380 	 * side is that we may wrap lines or scroll the screen before it's
381 	 * strictly necessary.  Not a big deal.
382 	 */
383 	if (LF_ISSET(TXT_APPENDEOL)) {
384 		tp->lb[tp->cno] = CH_CURSOR;
385 		++tp->len;
386 		++tp->insert;
387 		(void)vs_change(sp, tp->lno, LINE_RESET);
388 	}
389 
390 	/*
391 	 * Historic practice is that the wrapmargin value was a distance
392 	 * from the RIGHT-HAND margin, not the left.  It's more useful to
393 	 * us as a distance from the left-hand margin, i.e. the same as
394 	 * the wraplen value.  The wrapmargin option is historic practice.
395 	 * Nvi added the wraplen option so that it would be possible to
396 	 * edit files with consistent margins without knowing the number of
397 	 * columns in the window.
398 	 *
399 	 * XXX
400 	 * Setting margin causes a significant performance hit.  Normally
401 	 * we don't update the screen if there are keys waiting, but we
402 	 * have to if margin is set, otherwise the screen routines don't
403 	 * know where the cursor is.
404 	 *
405 	 * !!!
406 	 * Abbreviated keys were affected by the wrapmargin option in the
407 	 * historic 4BSD vi.  Mapped keys were usually, but sometimes not.
408 	 * See the comment in vi/v_text():set_txt_std for more information.
409 	 *
410 	 * !!!
411 	 * One more special case.  If an inserted <blank> character causes
412 	 * wrapmargin to split the line, the next user entered character is
413 	 * discarded if it's a <space> character.
414 	 */
415 	wm_set = wm_skip = 0;
416 	if (LF_ISSET(TXT_WRAPMARGIN))
417 		if ((margin = O_VAL(sp, O_WRAPMARGIN)) != 0)
418 			margin = sp->cols - margin;
419 		else
420 			margin = O_VAL(sp, O_WRAPLEN);
421 	else
422 		margin = 0;
423 
424 	/* Initialize abbreviation checks. */
425 	abcnt = ab_turnoff = 0;
426 	abb = F_ISSET(gp, G_ABBREV) &&
427 	    LF_ISSET(TXT_MAPINPUT) ? AB_INWORD : AB_NOTSET;
428 
429 	/*
430 	 * Set up the dot command.  Dot commands are done by saving the actual
431 	 * characters and then reevaluating them so that things like wrapmargin
432 	 * can change between the insert and the replay.
433 	 *
434 	 * !!!
435 	 * Historically, vi did not remap or reabbreviate replayed input.  (It
436 	 * did beep at you if you changed an abbreviation and then replayed the
437 	 * input.  We're not that compatible.)  We don't have to do anything to
438 	 * avoid remapping, as we're not getting characters from the terminal
439 	 * routines.  Turn the abbreviation check off.
440 	 *
441 	 * XXX
442 	 * It would be nice if we could swallow backspaces and such, but it's
443 	 * not all that easy to do.  What we can do is turn off the common
444 	 * error messages during the replay.  Otherwise, when the user enters
445 	 * an illegal command, e.g., "Ia<erase><erase><erase><erase>b<escape>",
446 	 * and then does a '.', they get a list of error messages after command
447 	 * completion.
448 	 */
449 	rcol = 0;
450 	if (LF_ISSET(TXT_REPLAY)) {
451 		abb = AB_NOTSET;
452 		LF_CLR(TXT_RECORD);
453 	}
454 
455 	/* Other text input mode setup. */
456 	quote = Q_NOTSET;
457 	carat = C_NOTSET;
458 	nochange = 0;
459 	FL_INIT(is_flags,
460 	    LF_ISSET(TXT_SEARCHINCR) ? IS_RESTART | IS_RUNNING : 0);
461 	filec_redraw = hexcnt = showmatch = 0;
462 
463 	/* Initialize input flags. */
464 	ec_flags = LF_ISSET(TXT_MAPINPUT) ? EC_MAPINPUT : 0;
465 
466 	/* Refresh the screen. */
467 	UPDATE_POSITION(sp, tp);
468 	if (vs_refresh(sp, 1))
469 		return (1);
470 
471 	/* If it's dot, just do it now. */
472 	if (F_ISSET(vp, VC_ISDOT))
473 		goto replay;
474 
475 	/* Get an event. */
476 	evp = &ev;
477 next:	if (v_event_get(sp, evp, 0, ec_flags))
478 		return (1);
479 
480 	/*
481 	 * If file completion overwrote part of the screen and nothing else has
482 	 * been displayed, clean up.  We don't do this as part of the normal
483 	 * message resolution because we know the user is on the colon command
484 	 * line and there's no reason to enter explicit characters to continue.
485 	 */
486 	if (filec_redraw && !F_ISSET(sp, SC_SCR_EXWROTE)) {
487 		filec_redraw = 0;
488 
489 		fc.e_event = E_REPAINT;
490 		fc.e_flno = vip->totalcount >=
491 		    sp->rows ? 1 : sp->rows - vip->totalcount;
492 		fc.e_tlno = sp->rows;
493 		vip->linecount = vip->lcontinue = vip->totalcount = 0;
494 		(void)vs_repaint(sp, &fc);
495 		(void)vs_refresh(sp, 1);
496 	}
497 
498 	/* Deal with all non-character events. */
499 	switch (evp->e_event) {
500 	case E_CHARACTER:
501 		break;
502 	case E_ERR:
503 	case E_EOF:
504 		F_SET(sp, SC_EXIT_FORCE);
505 		return (1);
506 	case E_INTERRUPT:
507 		/*
508 		 * !!!
509 		 * Historically, <interrupt> exited the user from text input
510 		 * mode or cancelled a colon command, and returned to command
511 		 * mode.  It also beeped the terminal, but that seems a bit
512 		 * excessive.
513 		 */
514 		goto k_escape;
515 	case E_REPAINT:
516 		if (vs_repaint(sp, &ev))
517 			return (1);
518 		goto next;
519 	case E_WRESIZE:
520 		/* <resize> interrupts the input mode. */
521 		v_emsg(sp, NULL, VIM_WRESIZE);
522 		goto k_escape;
523 	default:
524 		v_event_err(sp, evp);
525 		goto k_escape;
526 	}
527 
528 	/*
529 	 * !!!
530 	 * If the first character of the input is a nul, replay the previous
531 	 * input.  (Historically, it's okay to replay non-existent input.)
532 	 * This was not documented as far as I know, and is a great test of vi
533 	 * clones.
534 	 */
535 	if (LF_ISSET(TXT_RECORD) && rcol == 0 && evp->e_c == '\0') {
536 		if (vip->rep == NULL)
537 			goto done;
538 
539 		abb = AB_NOTSET;
540 		LF_CLR(TXT_RECORD);
541 		LF_SET(TXT_REPLAY);
542 		goto replay;
543 	}
544 
545 	/*
546 	 * File name completion and colon command-line editing.   We don't
547 	 * have enough meta characters, so we expect people to overload
548 	 * them.  If the two characters are the same, then we do file name
549 	 * completion if the cursor is past the first column, and do colon
550 	 * command-line editing if it's not.
551 	 */
552 	if (quote == Q_NOTSET) {
553 		int L__cedit, L__filec;
554 
555 		L__cedit = L__filec = 0;
556 		if (LF_ISSET(TXT_CEDIT) && O_STR(sp, O_CEDIT) != NULL &&
557 		    O_STR(sp, O_CEDIT)[0] == evp->e_c)
558 			L__cedit = 1;
559 		if (LF_ISSET(TXT_FILEC) && O_STR(sp, O_FILEC) != NULL &&
560 		    O_STR(sp, O_FILEC)[0] == evp->e_c)
561 			L__filec = 1;
562 		if (L__cedit == 1 && (L__filec == 0 || tp->cno == tp->offset)) {
563 			tp->term = TERM_CEDIT;
564 			goto k_escape;
565 		}
566 		if (L__filec == 1) {
567 			if (txt_fc(sp, tp, &filec_redraw))
568 				goto err;
569 			goto resolve;
570 		}
571 	}
572 
573 	/* Abbreviation overflow check.  See comment in txt_abbrev(). */
574 #define	MAX_ABBREVIATION_EXPANSION	256
575 	if (F_ISSET(&evp->e_ch, CH_ABBREVIATED)) {
576 		if (++abcnt > MAX_ABBREVIATION_EXPANSION) {
577 			if (v_event_flush(sp, CH_ABBREVIATED))
578 				msgq(sp, M_ERR,
579 "191|Abbreviation exceeded expansion limit: characters discarded");
580 			abcnt = 0;
581 			if (LF_ISSET(TXT_REPLAY))
582 				goto done;
583 			goto resolve;
584 		}
585 	} else
586 		abcnt = 0;
587 
588 	/* Check to see if the character fits into the replay buffers. */
589 	if (LF_ISSET(TXT_RECORD)) {
590 		BINC_GOTO(sp, EVENT, vip->rep,
591 		    vip->rep_len, (rcol + 1) * sizeof(EVENT));
592 		vip->rep[rcol++] = *evp;
593 	}
594 
595 replay:	if (LF_ISSET(TXT_REPLAY)) {
596 		if (rcol == vip->rep_cnt)
597 			goto k_escape;
598 		evp = vip->rep + rcol++;
599 	}
600 
601 	/* Wrapmargin check for leading space. */
602 	if (wm_skip) {
603 		wm_skip = 0;
604 		if (evp->e_c == ' ')
605 			goto resolve;
606 	}
607 
608 	/* If quoted by someone else, simply insert the character. */
609 	if (F_ISSET(&evp->e_ch, CH_QUOTED))
610 		goto insq_ch;
611 
612 	/*
613 	 * !!!
614 	 * If this character was quoted by a K_VLNEXT, replace the placeholder
615 	 * (a carat) with the new character.  We've already adjusted the cursor
616 	 * because it has to appear on top of the placeholder character.
617 	 * Historic practice.
618 	 *
619 	 * Skip tests for abbreviations; ":ab xa XA" followed by "ixa^V<space>"
620 	 * doesn't perform an abbreviation.  Special case, ^V^J (not ^V^M) is
621 	 * the same as ^J, historically.
622 	 */
623 	if (quote == Q_VTHIS) {
624 		FL_CLR(ec_flags, EC_QUOTED);
625 		if (LF_ISSET(TXT_MAPINPUT))
626 			FL_SET(ec_flags, EC_MAPINPUT);
627 
628 		if (evp->e_value != K_NL) {
629 			quote = Q_NOTSET;
630 			goto insl_ch;
631 		}
632 		quote = Q_NOTSET;
633 	}
634 
635 	/*
636 	 * !!!
637 	 * Translate "<CH_HEX>[isxdigit()]*" to a character with a hex value:
638 	 * this test delimits the value by any non-hex character.  Offset by
639 	 * one, we use 0 to mean that we've found <CH_HEX>.
640 	 */
641 	if (hexcnt > 1 && !ISXDIGIT(evp->e_c)) {
642 		hexcnt = 0;
643 		if (txt_hex(sp, tp))
644 			goto err;
645 	}
646 
647 	switch (evp->e_value) {
648 	case K_CR:				/* Carriage return. */
649 	case K_NL:				/* New line. */
650 		/* Return in script windows and the command line. */
651 k_cr:		if (LF_ISSET(TXT_CR)) {
652 			/*
653 			 * If this was a map, we may have not displayed
654 			 * the line.  Display it, just in case.
655 			 *
656 			 * If a script window and not the colon line,
657 			 * push a <cr> so it gets executed.
658 			 */
659 			if (LF_ISSET(TXT_INFOLINE)) {
660 				if (vs_change(sp, tp->lno, LINE_RESET))
661 					goto err;
662 			} else if (F_ISSET(sp, SC_SCRIPT))
663 				(void)v_event_push(sp, NULL, L("\r"), 1, CH_NOMAP);
664 
665 			/* Set term condition: if empty. */
666 			if (tp->cno <= tp->offset)
667 				tp->term = TERM_CR;
668 			/*
669 			 * Set term condition: if searching incrementally and
670 			 * the user entered a pattern, return a completed
671 			 * search, regardless if the entire pattern was found.
672 			 */
673 			if (FL_ISSET(is_flags, IS_RUNNING) &&
674 			    tp->cno >= tp->offset + 1)
675 				tp->term = TERM_SEARCH;
676 
677 			goto k_escape;
678 		}
679 
680 #define	LINE_RESOLVE do {						\
681 		/*							\
682 		 * Handle abbreviations.  If there was one, discard the	\
683 		 * replay characters.					\
684 		 */							\
685 		if (abb == AB_INWORD &&					\
686 		    !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {	\
687 			if (txt_abbrev(sp, tp, &evp->e_c,		\
688 			    LF_ISSET(TXT_INFOLINE), &tmp,		\
689 			    &ab_turnoff))				\
690 				goto err;				\
691 			if (tmp) {					\
692 				if (LF_ISSET(TXT_RECORD))		\
693 					rcol -= tmp + 1;		\
694 				goto resolve;				\
695 			}						\
696 		}							\
697 		if (abb != AB_NOTSET)					\
698 			abb = AB_NOTWORD;				\
699 		if (UNMAP_TST)						\
700 			txt_unmap(sp, tp, &ec_flags);			\
701 		/*							\
702 		 * Delete any appended cursor.  It's possible to get in	\
703 		 * situations where TXT_APPENDEOL is set but tp->insert	\
704 		 * is 0 when using the R command and all the characters	\
705 		 * are tp->owrite characters.				\
706 		 */							\
707 		if (LF_ISSET(TXT_APPENDEOL) && tp->insert > 0) {	\
708 			--tp->len;					\
709 			--tp->insert;					\
710 		}							\
711 } while (0)
712 		LINE_RESOLVE;
713 
714 		/*
715 		 * Save the current line information for restoration in
716 		 * txt_backup(), and set the line final length.
717 		 */
718 		tp->sv_len = tp->len;
719 		tp->sv_cno = tp->cno;
720 		tp->len = tp->cno;
721 
722 		/* Update the old line. */
723 		if (vs_change(sp, tp->lno, LINE_RESET))
724 			goto err;
725 
726 		/*
727 		 * Historic practice, when the autoindent edit option was set,
728 		 * was to delete <blank> characters following the inserted
729 		 * newline.  This affected the 'R', 'c', and 's' commands; 'c'
730 		 * and 's' retained the insert characters only, 'R' moved the
731 		 * overwrite and insert characters into the next TEXT structure.
732 		 * We keep track of the number of characters erased for the 'R'
733 		 * command so that the final resolution of the line is correct.
734 		 */
735 		tp->R_erase = 0;
736 		owrite = tp->owrite;
737 		insert = tp->insert;
738 		if (LF_ISSET(TXT_REPLACE) && owrite != 0) {
739 			for (p = tp->lb + tp->cno; owrite > 0 && isblank(*p);
740 			    ++p, --owrite, ++tp->R_erase);
741 			if (owrite == 0)
742 				for (; insert > 0 && isblank(*p);
743 				    ++p, ++tp->R_erase, --insert);
744 		} else {
745 			p = tp->lb + tp->cno + owrite;
746 			if (O_ISSET(sp, O_AUTOINDENT))
747 				for (; insert > 0 &&
748 				    isblank(*p); ++p, --insert);
749 			owrite = 0;
750 		}
751 
752 		/*
753 		 * !!!
754 		 * Create a new line and insert the new TEXT into the queue.
755 		 * DON'T insert until the old line has been updated, or the
756 		 * inserted line count in line.c:db_get() will be wrong.
757 		 */
758 		if ((ntp = text_init(sp, p,
759 		    insert + owrite, insert + owrite + 32)) == NULL)
760 			goto err;
761 		TAILQ_INSERT_TAIL(sp->tiq, ntp, q);
762 
763 		/* Set up bookkeeping for the new line. */
764 		ntp->insert = insert;
765 		ntp->owrite = owrite;
766 		ntp->lno = tp->lno + 1;
767 
768 		/*
769 		 * Reset the autoindent line value.  0^D keeps the autoindent
770 		 * line from changing, ^D changes the level, even if there were
771 		 * no characters in the old line.  Note, if using the current
772 		 * tp structure, use the cursor as the length, the autoindent
773 		 * characters may have been erased.
774 		 */
775 		if (LF_ISSET(TXT_AUTOINDENT)) {
776 			if (nochange) {
777 				nochange = 0;
778 				if (v_txt_auto(sp, OOBLNO, &ait, ait.ai, ntp))
779 					goto err;
780 				FREE_SPACEW(sp, ait.lb, ait.lb_len);
781 			} else
782 				if (v_txt_auto(sp, OOBLNO, tp, tp->cno, ntp))
783 					goto err;
784 			carat = C_NOTSET;
785 		}
786 
787 		/* Reset the cursor. */
788 		ntp->cno = ntp->ai;
789 
790 		/*
791 		 * If we're here because wrapmargin was set and we've broken a
792 		 * line, there may be additional information (i.e. the start of
793 		 * a line) in the wmt structure.
794 		 */
795 		if (wm_set) {
796 			if (wmt.offset != 0 ||
797 			    wmt.owrite != 0 || wmt.insert != 0) {
798 #define	WMTSPACE	wmt.offset + wmt.owrite + wmt.insert
799 				BINC_GOTOW(sp, ntp->lb,
800 				    ntp->lb_len, ntp->len + WMTSPACE + 32);
801 				MEMMOVE(ntp->lb + ntp->cno, wmt.lb, WMTSPACE);
802 				ntp->len += WMTSPACE;
803 				ntp->cno += wmt.offset;
804 				ntp->owrite = wmt.owrite;
805 				ntp->insert = wmt.insert;
806 			}
807 			wm_set = 0;
808 		}
809 
810 		/* New lines are TXT_APPENDEOL. */
811 		if (ntp->owrite == 0 && ntp->insert == 0) {
812 			BINC_GOTOW(sp, ntp->lb, ntp->lb_len, ntp->len + 1);
813 			LF_SET(TXT_APPENDEOL);
814 			ntp->lb[ntp->cno] = CH_CURSOR;
815 			++ntp->insert;
816 			++ntp->len;
817 		}
818 
819 		/* Swap old and new TEXT's, and update the new line. */
820 		tp = ntp;
821 		if (vs_change(sp, tp->lno, LINE_INSERT))
822 			goto err;
823 
824 		goto resolve;
825 	case K_ESCAPE:				/* Escape. */
826 		if (!LF_ISSET(TXT_ESCAPE))
827 			goto ins_ch;
828 
829 		/* If we have a count, start replaying the input. */
830 		if (rcount > 1) {
831 			--rcount;
832 
833 			vip->rep_cnt = rcol;
834 			rcol = 0;
835 			abb = AB_NOTSET;
836 			LF_CLR(TXT_RECORD);
837 			LF_SET(TXT_REPLAY);
838 
839 			/*
840 			 * Some commands (e.g. 'o') need a <newline> for each
841 			 * repetition.
842 			 */
843 			if (LF_ISSET(TXT_ADDNEWLINE))
844 				goto k_cr;
845 
846 			/*
847 			 * The R command turns into the 'a' command after the
848 			 * first repetition.
849 			 */
850 			if (LF_ISSET(TXT_REPLACE)) {
851 				tp->insert = tp->owrite;
852 				tp->owrite = 0;
853 				LF_CLR(TXT_REPLACE);
854 			}
855 			goto replay;
856 		}
857 
858 		/* Set term condition: if empty. */
859 		if (tp->cno <= tp->offset)
860 			tp->term = TERM_ESC;
861 		/*
862 		 * Set term condition: if searching incrementally and the user
863 		 * entered a pattern, return a completed search, regardless if
864 		 * the entire pattern was found.
865 		 */
866 		if (FL_ISSET(is_flags, IS_RUNNING) && tp->cno >= tp->offset + 1)
867 			tp->term = TERM_SEARCH;
868 
869 k_escape:	LINE_RESOLVE;
870 
871 		/*
872 		 * Clean up for the 'R' command, restoring overwrite
873 		 * characters, and making them into insert characters.
874 		 */
875 		if (LF_ISSET(TXT_REPLACE))
876 			txt_Rresolve(sp, sp->tiq, tp, len);
877 
878 		/*
879 		 * If there are any overwrite characters, copy down
880 		 * any insert characters, and decrement the length.
881 		 */
882 		if (tp->owrite) {
883 			if (tp->insert)
884 				MEMMOVE(tp->lb + tp->cno,
885 				    tp->lb + tp->cno + tp->owrite, tp->insert);
886 			tp->len -= tp->owrite;
887 		}
888 
889 		/*
890 		 * Optionally resolve the lines into the file.  If not
891 		 * resolving the lines into the file, end the line with
892 		 * a nul.  If the line is empty, then set the length to
893 		 * 0, the termination condition has already been set.
894 		 *
895 		 * XXX
896 		 * This is wrong, should pass back a length.
897 		 */
898 		if (LF_ISSET(TXT_RESOLVE)) {
899 			if (txt_resolve(sp, sp->tiq, flags))
900 				goto err;
901 		} else {
902 			BINC_GOTOW(sp, tp->lb, tp->lb_len, tp->len + 1);
903 			tp->lb[tp->len] = '\0';
904 		}
905 
906 		/*
907 		 * Set the return cursor position to rest on the last
908 		 * inserted character.
909 		 */
910 		if (tp->cno != 0)
911 			--tp->cno;
912 
913 		/* Update the last line. */
914 		if (vs_change(sp, tp->lno, LINE_RESET))
915 			return (1);
916 		goto done;
917 	case K_CARAT:			/* Delete autoindent chars. */
918 		if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
919 			carat = C_CARATSET;
920 		goto ins_ch;
921 	case K_ZERO:			/* Delete autoindent chars. */
922 		if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
923 			carat = C_ZEROSET;
924 		goto ins_ch;
925 	case K_CNTRLD:			/* Delete autoindent char. */
926 		/*
927 		 * If in the first column or no characters to erase, ignore
928 		 * the ^D (this matches historic practice).  If not doing
929 		 * autoindent or already inserted non-ai characters, it's a
930 		 * literal.  The latter test is done in the switch, as the
931 		 * CARAT forms are N + 1, not N.
932 		 */
933 		if (!LF_ISSET(TXT_AUTOINDENT))
934 			goto ins_ch;
935 		if (tp->cno == 0)
936 			goto resolve;
937 
938 		switch (carat) {
939 		case C_CARATSET:	/* ^^D */
940 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
941 				goto ins_ch;
942 
943 			/* Save the ai string for later. */
944 			ait.lb = NULL;
945 			ait.lb_len = 0;
946 			BINC_GOTOW(sp, ait.lb, ait.lb_len, tp->ai);
947 			MEMMOVE(ait.lb, tp->lb, tp->ai);
948 			ait.ai = ait.len = tp->ai;
949 
950 			carat = C_NOTSET;
951 			nochange = 1;
952 			goto leftmargin;
953 		case C_ZEROSET:		/* 0^D */
954 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
955 				goto ins_ch;
956 
957 			carat = C_NOTSET;
958 leftmargin:		tp->lb[tp->cno - 1] = ' ';
959 			tp->owrite += tp->cno - tp->offset;
960 			tp->ai = 0;
961 			tp->cno = tp->offset;
962 			break;
963 		case C_NOTSET:		/* ^D */
964 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset)
965 				goto ins_ch;
966 
967 			(void)txt_dent(sp, tp, O_SHIFTWIDTH, 0);
968 			break;
969 		default:
970 			abort();
971 		}
972 		break;
973 	case K_VERASE:			/* Erase the last character. */
974 		/* If can erase over the prompt, return. */
975 		if (tp->cno <= tp->offset && LF_ISSET(TXT_BS)) {
976 			tp->term = TERM_BS;
977 			goto done;
978 		}
979 
980 		/*
981 		 * If at the beginning of the line, try and drop back to a
982 		 * previously inserted line.
983 		 */
984 		if (tp->cno == 0) {
985 			if ((ntp =
986 			    txt_backup(sp, sp->tiq, tp, &flags)) == NULL)
987 				goto err;
988 			tp = ntp;
989 			break;
990 		}
991 
992 		/* If nothing to erase, bell the user. */
993 		if (tp->cno <= tp->offset) {
994 			if (!LF_ISSET(TXT_REPLAY))
995 				txt_nomorech(sp);
996 			break;
997 		}
998 
999 		/* Drop back one character. */
1000 		--tp->cno;
1001 
1002 		/*
1003 		 * Historically, vi didn't replace the erased characters with
1004 		 * <blank>s, presumably because it's easier to fix a minor
1005 		 * typing mistake and continue on if the previous letters are
1006 		 * already there.  This is a problem for incremental searching,
1007 		 * because the user can no longer tell where they are in the
1008 		 * colon command line because the cursor is at the last search
1009 		 * point in the screen.  So, if incrementally searching, erase
1010 		 * the erased characters from the screen.
1011 		 */
1012 		if (FL_ISSET(is_flags, IS_RUNNING))
1013 			tp->lb[tp->cno] = ' ';
1014 
1015 		/*
1016 		 * Increment overwrite, decrement ai if deleted.
1017 		 *
1018 		 * !!!
1019 		 * Historic vi did not permit users to use erase characters
1020 		 * to delete autoindent characters.  We do.  Eat hot death,
1021 		 * POSIX.
1022 		 */
1023 		++tp->owrite;
1024 		if (tp->cno < tp->ai)
1025 			--tp->ai;
1026 
1027 		/* Reset if we deleted an incremental search character. */
1028 		if (FL_ISSET(is_flags, IS_RUNNING))
1029 			FL_SET(is_flags, IS_RESTART);
1030 		break;
1031 	case K_VWERASE:			/* Skip back one word. */
1032 		/*
1033 		 * If at the beginning of the line, try and drop back to a
1034 		 * previously inserted line.
1035 		 */
1036 		if (tp->cno == 0) {
1037 			if ((ntp =
1038 			    txt_backup(sp, sp->tiq, tp, &flags)) == NULL)
1039 				goto err;
1040 			tp = ntp;
1041 		}
1042 
1043 		/*
1044 		 * If at offset, nothing to erase so bell the user.
1045 		 */
1046 		if (tp->cno <= tp->offset) {
1047 			if (!LF_ISSET(TXT_REPLAY))
1048 				txt_nomorech(sp);
1049 			break;
1050 		}
1051 
1052 		/*
1053 		 * The first werase goes back to any autoindent column and the
1054 		 * second werase goes back to the offset.
1055 		 *
1056 		 * !!!
1057 		 * Historic vi did not permit users to use erase characters to
1058 		 * delete autoindent characters.
1059 		 */
1060 		if (tp->ai && tp->cno > tp->ai)
1061 			max = tp->ai;
1062 		else {
1063 			tp->ai = 0;
1064 			max = tp->offset;
1065 		}
1066 
1067 		/* Skip over trailing space characters. */
1068 		while (tp->cno > max && ISBLANK(tp->lb[tp->cno - 1])) {
1069 			--tp->cno;
1070 			++tp->owrite;
1071 		}
1072 		if (tp->cno == max)
1073 			break;
1074 		/*
1075 		 * There are three types of word erase found on UNIX systems.
1076 		 * They can be identified by how the string /a/b/c is treated
1077 		 * -- as 1, 3, or 6 words.  Historic vi had two classes of
1078 		 * characters, and strings were delimited by them and
1079 		 * <blank>'s, so, 6 words.  The historic tty interface used
1080 		 * <blank>'s to delimit strings, so, 1 word.  The algorithm
1081 		 * offered in the 4.4BSD tty interface (as stty altwerase)
1082 		 * treats it as 3 words -- there are two classes of
1083 		 * characters, and strings are delimited by them and
1084 		 * <blank>'s.  The difference is that the type of the first
1085 		 * erased character erased is ignored, which is exactly right
1086 		 * when erasing pathname components.  The edit options
1087 		 * TXT_ALTWERASE and TXT_TTYWERASE specify the 4.4BSD tty
1088 		 * interface and the historic tty driver behavior,
1089 		 * respectively, and the default is the same as the historic
1090 		 * vi behavior.
1091 		 *
1092 		 * Overwrite erased characters if doing incremental search;
1093 		 * see comment above.
1094 		 */
1095 		if (LF_ISSET(TXT_TTYWERASE))
1096 			while (tp->cno > max) {
1097 				if (ISBLANK(tp->lb[tp->cno - 1]))
1098 					break;
1099 				--tp->cno;
1100 				++tp->owrite;
1101 				if (FL_ISSET(is_flags, IS_RUNNING))
1102 					tp->lb[tp->cno] = ' ';
1103 			}
1104 		else {
1105 			if (LF_ISSET(TXT_ALTWERASE)) {
1106 				--tp->cno;
1107 				++tp->owrite;
1108 				if (FL_ISSET(is_flags, IS_RUNNING))
1109 					tp->lb[tp->cno] = ' ';
1110 			}
1111 			if (tp->cno > max)
1112 				tmp = inword(tp->lb[tp->cno - 1]);
1113 			while (tp->cno > max) {
1114 				if (tmp != inword(tp->lb[tp->cno - 1])
1115 				    || ISBLANK(tp->lb[tp->cno - 1]))
1116 					break;
1117 				--tp->cno;
1118 				++tp->owrite;
1119 				if (FL_ISSET(is_flags, IS_RUNNING))
1120 					tp->lb[tp->cno] = ' ';
1121 			}
1122 		}
1123 
1124 		/* Reset if we deleted an incremental search character. */
1125 		if (FL_ISSET(is_flags, IS_RUNNING))
1126 			FL_SET(is_flags, IS_RESTART);
1127 		break;
1128 	case K_VKILL:			/* Restart this line. */
1129 		/*
1130 		 * !!!
1131 		 * If at the beginning of the line, try and drop back to a
1132 		 * previously inserted line.  Historic vi did not permit
1133 		 * users to go back to previous lines.
1134 		 */
1135 		if (tp->cno == 0) {
1136 			if ((ntp =
1137 			    txt_backup(sp, sp->tiq, tp, &flags)) == NULL)
1138 				goto err;
1139 			tp = ntp;
1140 		}
1141 
1142 		/* If at offset, nothing to erase so bell the user. */
1143 		if (tp->cno <= tp->offset) {
1144 			if (!LF_ISSET(TXT_REPLAY))
1145 				txt_nomorech(sp);
1146 			break;
1147 		}
1148 
1149 		/*
1150 		 * First kill goes back to any autoindent and second kill goes
1151 		 * back to the offset.
1152 		 *
1153 		 * !!!
1154 		 * Historic vi did not permit users to use erase characters to
1155 		 * delete autoindent characters.
1156 		 */
1157 		if (tp->ai && tp->cno > tp->ai)
1158 			max = tp->ai;
1159 		else {
1160 			tp->ai = 0;
1161 			max = tp->offset;
1162 		}
1163 		tp->owrite += tp->cno - max;
1164 
1165 		/*
1166 		 * Overwrite erased characters if doing incremental search;
1167 		 * see comment above.
1168 		 */
1169 		if (FL_ISSET(is_flags, IS_RUNNING))
1170 			do {
1171 				tp->lb[--tp->cno] = ' ';
1172 			} while (tp->cno > max);
1173 		else
1174 			tp->cno = max;
1175 
1176 		/* Reset if we deleted an incremental search character. */
1177 		if (FL_ISSET(is_flags, IS_RUNNING))
1178 			FL_SET(is_flags, IS_RESTART);
1179 		break;
1180 	case K_CNTRLT:			/* Add autoindent characters. */
1181 		if (!LF_ISSET(TXT_CNTRLT))
1182 			goto ins_ch;
1183 		if (txt_dent(sp, tp, O_SHIFTWIDTH, 1))
1184 			goto err;
1185 		goto ebuf_chk;
1186 	case K_VLNEXT:			/* Quote next character. */
1187 		evp->e_c = '^';
1188 		quote = Q_VNEXT;
1189 		/*
1190 		 * Turn on the quote flag so that the underlying routines
1191 		 * quote the next character where it's possible. Turn off
1192 		 * the input mapbiting flag so that we don't remap the next
1193 		 * character.
1194 		 */
1195 		FL_SET(ec_flags, EC_QUOTED);
1196 		FL_CLR(ec_flags, EC_MAPINPUT);
1197 
1198 		/*
1199 		 * !!!
1200 		 * Skip the tests for abbreviations, so ":ab xa XA",
1201 		 * "ixa^V<space>" doesn't perform the abbreviation.
1202 		 */
1203 		goto insl_ch;
1204 	case K_HEXCHAR:
1205 		hexcnt = 1;
1206 		goto insq_ch;
1207 	case K_TAB:
1208 		if (sp->showmode != SM_COMMAND && quote != Q_VTHIS &&
1209 		    O_ISSET(sp, O_EXPANDTAB)) {
1210 			if (txt_dent(sp, tp, O_TABSTOP, 1))
1211 				goto err;
1212 			goto ebuf_chk;
1213 		}
1214 		goto insq_ch;
1215 	default:			/* Insert the character. */
1216 		if (LF_ISSET(TXT_SHOWMATCH)) {
1217 			CHAR_T *match_chars, *cp;
1218 
1219 			match_chars = VIP(sp)->mcs;
1220 			cp = STRCHR(match_chars, evp->e_c);
1221 			if (cp != NULL && (cp - match_chars) & 1)
1222 				showmatch = 1;
1223 		}
1224 ins_ch:		/*
1225 		 * Historically, vi eliminated nul's out of hand.  If the
1226 		 * beautify option was set, it also deleted any unknown
1227 		 * ASCII value less than space (040) and the del character
1228 		 * (0177), except for tabs.  Unknown is a key word here.
1229 		 * Most vi documentation claims that it deleted everything
1230 		 * but <tab>, <nl> and <ff>, as that's what the original
1231 		 * 4BSD documentation said.  This is obviously wrong,
1232 		 * however, as <esc> would be included in that list.  What
1233 		 * we do is eliminate any unquoted, iscntrl() character that
1234 		 * wasn't a replay and wasn't handled specially, except
1235 		 * <tab> or <ff>.
1236 		 */
1237 		if (LF_ISSET(TXT_BEAUTIFY) && ISCNTRL(evp->e_c) &&
1238 		    evp->e_value != K_FORMFEED && evp->e_value != K_TAB) {
1239 			msgq(sp, M_BERR,
1240 			    "192|Illegal character; quote to enter");
1241 			if (LF_ISSET(TXT_REPLAY))
1242 				goto done;
1243 			break;
1244 		}
1245 
1246 insq_ch:	/*
1247 		 * If entering a non-word character after a word, check for
1248 		 * abbreviations.  If there was one, discard replay characters.
1249 		 * If entering a blank character, check for unmap commands,
1250 		 * as well.
1251 		 */
1252 		if (!inword(evp->e_c)) {
1253 			if (abb == AB_INWORD &&
1254 			    !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {
1255 				if (txt_abbrev(sp, tp, &evp->e_c,
1256 				    LF_ISSET(TXT_INFOLINE), &tmp, &ab_turnoff))
1257 					goto err;
1258 				if (tmp) {
1259 					if (LF_ISSET(TXT_RECORD))
1260 						rcol -= tmp + 1;
1261 					goto resolve;
1262 				}
1263 			}
1264 			if (isblank(evp->e_c) && UNMAP_TST)
1265 				txt_unmap(sp, tp, &ec_flags);
1266 		}
1267 		if (abb != AB_NOTSET)
1268 			abb = inword(evp->e_c) ? AB_INWORD : AB_NOTWORD;
1269 
1270 insl_ch:	if (txt_insch(sp, tp, &evp->e_c, flags))
1271 			goto err;
1272 
1273 		/*
1274 		 * If we're using K_VLNEXT to quote the next character, then
1275 		 * we want the cursor to position itself on the ^ placeholder
1276 		 * we're displaying, to match historic practice.
1277 		 */
1278 		if (quote == Q_VNEXT) {
1279 			--tp->cno;
1280 			++tp->owrite;
1281 		}
1282 
1283 		/*
1284 		 * !!!
1285 		 * Translate "<CH_HEX>[isxdigit()]*" to a character with
1286 		 * a hex value: this test delimits the value by the max
1287 		 * number of hex bytes.  Offset by one, we use 0 to mean
1288 		 * that we've found <CH_HEX>.
1289 		 */
1290 		if (hexcnt != 0 && hexcnt++ == 3) {
1291 			hexcnt = 0;
1292 			if (txt_hex(sp, tp))
1293 				goto err;
1294 		}
1295 
1296 		/*
1297 		 * Check to see if we've crossed the margin.
1298 		 *
1299 		 * !!!
1300 		 * In the historic vi, the wrapmargin value was figured out
1301 		 * using the display widths of the characters, i.e. <tab>
1302 		 * characters were counted as two characters if the list edit
1303 		 * option is set, but as the tabstop edit option number of
1304 		 * characters otherwise.  That's what the vs_column() function
1305 		 * gives us, so we use it.
1306 		 */
1307 		if (margin != 0) {
1308 			if (vs_column(sp, &tcol))
1309 				goto err;
1310 			if (tcol >= margin) {
1311 				if (txt_margin(sp, tp, &wmt, &tmp, flags))
1312 					goto err;
1313 				if (tmp) {
1314 					if (isblank(evp->e_c))
1315 						wm_skip = 1;
1316 					wm_set = 1;
1317 					goto k_cr;
1318 				}
1319 			}
1320 		}
1321 
1322 		/*
1323 		 * If we've reached the end of the buffer, then we need to
1324 		 * switch into insert mode.  This happens when there's a
1325 		 * change to a mark and the user puts in more characters than
1326 		 * the length of the motion.
1327 		 */
1328 ebuf_chk:	if (tp->cno >= tp->len) {
1329 			BINC_GOTOW(sp, tp->lb, tp->lb_len, tp->len + 1);
1330 			LF_SET(TXT_APPENDEOL);
1331 
1332 			tp->lb[tp->cno] = CH_CURSOR;
1333 			++tp->insert;
1334 			++tp->len;
1335 		}
1336 
1337 		/* Step the quote state forward. */
1338 		if (quote == Q_VNEXT)
1339 			quote = Q_VTHIS;
1340 		break;
1341 	}
1342 
1343 #ifdef DEBUG
1344 	if (tp->cno + tp->insert + tp->owrite != tp->len) {
1345 		msgq(sp, M_ERR,
1346 		    "len %zu != cno: %zu ai: %zu insert %zu overwrite %zu",
1347 		    tp->len, tp->cno, tp->ai, tp->insert, tp->owrite);
1348 		if (LF_ISSET(TXT_REPLAY))
1349 			goto done;
1350 		tp->len = tp->cno + tp->insert + tp->owrite;
1351 	}
1352 #endif
1353 
1354 resolve:/*
1355 	 * 1: If we don't need to know where the cursor really is and we're
1356 	 *    replaying text, keep going.
1357 	 */
1358 	if (margin == 0 && LF_ISSET(TXT_REPLAY))
1359 		goto replay;
1360 
1361 	/*
1362 	 * 2: Reset the line.  Don't bother unless we're about to wait on
1363 	 *    a character or we need to know where the cursor really is.
1364 	 *    We have to do this before showing matching characters so the
1365 	 *    user can see what they're matching.
1366 	 */
1367 	if ((margin != 0 || !KEYS_WAITING(sp)) &&
1368 	    vs_change(sp, tp->lno, LINE_RESET))
1369 		return (1);
1370 
1371 	/*
1372 	 * 3: If there aren't keys waiting, display the matching character.
1373 	 *    We have to do this before resolving any messages, otherwise
1374 	 *    the error message from a missing match won't appear correctly.
1375 	 */
1376 	if (showmatch) {
1377 		if (!KEYS_WAITING(sp) && txt_showmatch(sp, tp))
1378 			return (1);
1379 		showmatch = 0;
1380 	}
1381 
1382 	/*
1383 	 * 4: If there have been messages and we're not editing on the colon
1384 	 *    command line or doing file name completion, resolve them.
1385 	 */
1386 	if ((vip->totalcount != 0 || F_ISSET(gp, G_BELLSCHED)) &&
1387 	    !F_ISSET(sp, SC_TINPUT_INFO) && !filec_redraw &&
1388 	    vs_resolve(sp, NULL, 0))
1389 		return (1);
1390 
1391 	/*
1392 	 * 5: Refresh the screen if we're about to wait on a character or we
1393 	 *    need to know where the cursor really is.
1394 	 */
1395 	if (margin != 0 || !KEYS_WAITING(sp)) {
1396 		UPDATE_POSITION(sp, tp);
1397 		if (vs_refresh(sp, margin != 0))
1398 			return (1);
1399 	}
1400 
1401 	/* 6: Proceed with the incremental search. */
1402 	if (FL_ISSET(is_flags, IS_RUNNING) && txt_isrch(sp, vp, tp, &is_flags))
1403 		return (1);
1404 
1405 	/* 7: Next character... */
1406 	if (LF_ISSET(TXT_REPLAY))
1407 		goto replay;
1408 	goto next;
1409 
1410 done:	/* Leave input mode. */
1411 	F_CLR(sp, SC_TINPUT);
1412 
1413 	/* If recording for playback, save it. */
1414 	if (LF_ISSET(TXT_RECORD))
1415 		vip->rep_cnt = rcol;
1416 
1417 	/*
1418 	 * If not working on the colon command line, set the final cursor
1419 	 * position.
1420 	 */
1421 	if (!F_ISSET(sp, SC_TINPUT_INFO)) {
1422 		vp->m_final.lno = tp->lno;
1423 		vp->m_final.cno = tp->cno;
1424 	}
1425 	return (0);
1426 
1427 err:
1428 alloc_err:
1429 	F_CLR(sp, SC_TINPUT);
1430 	txt_err(sp, sp->tiq);
1431 	return (1);
1432 }
1433 
1434 /*
1435  * txt_abbrev --
1436  *	Handle abbreviations.
1437  */
1438 static int
1439 txt_abbrev(SCR *sp, TEXT *tp, CHAR_T *pushcp, int isinfoline, int *didsubp, int *turnoffp)
1440 {
1441 	VI_PRIVATE *vip;
1442 	CHAR_T ch, *p;
1443 	SEQ *qp;
1444 	size_t len, off;
1445 
1446 	/* Check to make sure we're not at the start of an append. */
1447 	*didsubp = 0;
1448 	if (tp->cno == tp->offset)
1449 		return (0);
1450 
1451 	vip = VIP(sp);
1452 
1453 	/*
1454 	 * Find the start of the "word".
1455 	 *
1456 	 * !!!
1457 	 * We match historic practice, which, as far as I can tell, had an
1458 	 * off-by-one error.  The way this worked was that when the inserted
1459 	 * text switched from a "word" character to a non-word character,
1460 	 * vi would check for possible abbreviations.  It would then take the
1461 	 * type (i.e. word/non-word) of the character entered TWO characters
1462 	 * ago, and move backward in the text until reaching a character that
1463 	 * was not that type, or the beginning of the insert, the line, or
1464 	 * the file.  For example, in the string "abc<space>", when the <space>
1465 	 * character triggered the abbreviation check, the type of the 'b'
1466 	 * character was used for moving through the string.  Maybe there's a
1467 	 * reason for not using the first (i.e. 'c') character, but I can't
1468 	 * think of one.
1469 	 *
1470 	 * Terminate at the beginning of the insert or the character after the
1471 	 * offset character -- both can be tested for using tp->offset.
1472 	 */
1473 	off = tp->cno - 1;			/* Previous character. */
1474 	p = tp->lb + off;
1475 	len = 1;				/* One character test. */
1476 	if (off == tp->offset || isblank(p[-1]))
1477 		goto search;
1478 	if (inword(p[-1]))			/* Move backward to change. */
1479 		for (;;) {
1480 			--off; --p; ++len;
1481 			if (off == tp->offset || !inword(p[-1]))
1482 				break;
1483 		}
1484 	else
1485 		for (;;) {
1486 			--off; --p; ++len;
1487 			if (off == tp->offset ||
1488 			    inword(p[-1]) || isblank(p[-1]))
1489 				break;
1490 		}
1491 
1492 	/*
1493 	 * !!!
1494 	 * Historic vi exploded abbreviations on the command line.  This has
1495 	 * obvious problems in that unabbreviating the string can be extremely
1496 	 * tricky, particularly if the string has, say, an embedded escape
1497 	 * character.  Personally, I think it's a stunningly bad idea.  Other
1498 	 * examples of problems this caused in historic vi are:
1499 	 *	:ab foo bar
1500 	 *	:ab foo baz
1501 	 * results in "bar" being abbreviated to "baz", which wasn't what the
1502 	 * user had in mind at all.  Also, the commands:
1503 	 *	:ab foo bar
1504 	 *	:unab foo<space>
1505 	 * resulted in an error message that "bar" wasn't mapped.  Finally,
1506 	 * since the string was already exploded by the time the unabbreviate
1507 	 * command got it, all it knew was that an abbreviation had occurred.
1508 	 * Cleverly, it checked the replacement string for its unabbreviation
1509 	 * match, which meant that the commands:
1510 	 *	:ab foo1 bar
1511 	 *	:ab foo2 bar
1512 	 *	:unab foo2
1513 	 * unabbreviate "foo1", and the commands:
1514 	 *	:ab foo bar
1515 	 *	:ab bar baz
1516 	 * unabbreviate "foo"!
1517 	 *
1518 	 * Anyway, people neglected to first ask my opinion before they wrote
1519 	 * macros that depend on this stuff, so, we make this work as follows.
1520 	 * When checking for an abbreviation on the command line, if we get a
1521 	 * string which is <blank> terminated and which starts at the beginning
1522 	 * of the line, we check to see it is the abbreviate or unabbreviate
1523 	 * commands.  If it is, turn abbreviations off and return as if no
1524 	 * abbreviation was found.  Note also, minor trickiness, so that if
1525 	 * the user erases the line and starts another command, we turn the
1526 	 * abbreviations back on.
1527 	 *
1528 	 * This makes the layering look like a Nachos Supreme.
1529 	 */
1530 search:	if (isinfoline) {
1531 		if (off == tp->ai || off == tp->offset)
1532 			if (ex_is_abbrev(p, len)) {
1533 				*turnoffp = 1;
1534 				return (0);
1535 			} else
1536 				*turnoffp = 0;
1537 		else
1538 			if (*turnoffp)
1539 				return (0);
1540 	}
1541 
1542 	/* Check for any abbreviations. */
1543 	if ((qp = seq_find(sp, NULL, NULL, p, len, SEQ_ABBREV, NULL)) == NULL)
1544 		return (0);
1545 
1546 	/*
1547 	 * Push the abbreviation onto the tty stack.  Historically, characters
1548 	 * resulting from an abbreviation expansion were themselves subject to
1549 	 * map expansions, O_SHOWMATCH matching etc.  This means the expanded
1550 	 * characters will be re-tested for abbreviations.  It's difficult to
1551 	 * know what historic practice in this case was, since abbreviations
1552 	 * were applied to :colon command lines, so entering abbreviations that
1553 	 * looped was tricky, although possible.  In addition, obvious loops
1554 	 * didn't work as expected.  (The command ':ab a b|ab b c|ab c a' will
1555 	 * silently only implement and/or display the last abbreviation.)
1556 	 *
1557 	 * This implementation doesn't recover well from such abbreviations.
1558 	 * The main input loop counts abbreviated characters, and, when it
1559 	 * reaches a limit, discards any abbreviated characters on the queue.
1560 	 * It's difficult to back up to the original position, as the replay
1561 	 * queue would have to be adjusted, and the line state when an initial
1562 	 * abbreviated character was received would have to be saved.
1563 	 */
1564 	ch = *pushcp;
1565 	if (v_event_push(sp, NULL, &ch, 1, CH_ABBREVIATED))
1566 		return (1);
1567 	if (v_event_push(sp, NULL, qp->output, qp->olen, CH_ABBREVIATED))
1568 		return (1);
1569 
1570 	/*
1571 	 * If the size of the abbreviation is larger than or equal to the size
1572 	 * of the original text, move to the start of the replaced characters,
1573 	 * and add their length to the overwrite count.
1574 	 *
1575 	 * If the abbreviation is smaller than the original text, we have to
1576 	 * delete the additional overwrite characters and copy down any insert
1577 	 * characters.
1578 	 */
1579 	tp->cno -= len;
1580 	if (qp->olen >= len)
1581 		tp->owrite += len;
1582 	else {
1583 		if (tp->insert)
1584 			MEMMOVE(tp->lb + tp->cno + qp->olen,
1585 			    tp->lb + tp->cno + tp->owrite + len, tp->insert);
1586 		tp->owrite += qp->olen;
1587 		tp->len -= len - qp->olen;
1588 	}
1589 
1590 	/*
1591 	 * We return the length of the abbreviated characters.  This is so
1592 	 * the calling routine can replace the replay characters with the
1593 	 * abbreviation.  This means that subsequent '.' commands will produce
1594 	 * the same text, regardless of intervening :[un]abbreviate commands.
1595 	 * This is historic practice.
1596 	 */
1597 	*didsubp = len;
1598 	return (0);
1599 }
1600 
1601 /*
1602  * txt_unmap --
1603  *	Handle the unmap command.
1604  */
1605 static void
1606 txt_unmap(SCR *sp, TEXT *tp, u_int32_t *ec_flagsp)
1607 {
1608 	size_t len, off;
1609 	CHAR_T *p;
1610 
1611 	/* Find the beginning of this "word". */
1612 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off) {
1613 		if (isblank(*p)) {
1614 			++p;
1615 			break;
1616 		}
1617 		++len;
1618 		if (off == tp->ai || off == tp->offset)
1619 			break;
1620 	}
1621 
1622 	/*
1623 	 * !!!
1624 	 * Historic vi exploded input mappings on the command line.  See the
1625 	 * txt_abbrev() routine for an explanation of the problems inherent
1626 	 * in this.
1627 	 *
1628 	 * We make this work as follows.  If we get a string which is <blank>
1629 	 * terminated and which starts at the beginning of the line, we check
1630 	 * to see it is the unmap command.  If it is, we return that the input
1631 	 * mapping should be turned off.  Note also, minor trickiness, so that
1632 	 * if the user erases the line and starts another command, we go ahead
1633 	 * an turn mapping back on.
1634 	 */
1635 	if ((off == tp->ai || off == tp->offset) && ex_is_unmap(p, len))
1636 		FL_CLR(*ec_flagsp, EC_MAPINPUT);
1637 	else
1638 		FL_SET(*ec_flagsp, EC_MAPINPUT);
1639 }
1640 
1641 /*
1642  * txt_ai_resolve --
1643  *	When a line is resolved by <esc>, review autoindent characters.
1644  */
1645 static void
1646 txt_ai_resolve(SCR *sp, TEXT *tp, int *changedp)
1647 {
1648 	u_long ts;
1649 	int del;
1650 	size_t cno, len, new, old, scno, spaces, tab_after_sp, tabs;
1651 	CHAR_T *p;
1652 
1653 	*changedp = 0;
1654 
1655 	/*
1656 	 * If the line is empty, has an offset, or no autoindent
1657 	 * characters, we're done.
1658 	 */
1659 	if (!tp->len || tp->offset || !tp->ai)
1660 		return;
1661 
1662 	/*
1663 	 * If the length is less than or equal to the autoindent
1664 	 * characters, delete them.
1665 	 */
1666 	if (tp->len <= tp->ai) {
1667 		tp->ai = tp->cno = tp->len = 0;
1668 		return;
1669 	}
1670 
1671 	/*
1672 	 * The autoindent characters plus any leading <blank> characters
1673 	 * in the line are resolved into the minimum number of characters.
1674 	 * Historic practice.
1675 	 */
1676 	ts = O_VAL(sp, O_TABSTOP);
1677 
1678 	/* Figure out the last <blank> screen column. */
1679 	for (p = tp->lb, scno = 0, len = tp->len,
1680 	    spaces = tab_after_sp = 0; len-- && isblank(*p); ++p)
1681 		if (*p == '\t') {
1682 			if (spaces)
1683 				tab_after_sp = 1;
1684 			scno += COL_OFF(scno, ts);
1685 		} else {
1686 			++spaces;
1687 			++scno;
1688 		}
1689 
1690 	/*
1691 	 * If there are no spaces, or no tabs after spaces and less than
1692 	 * ts spaces, it's already minimal.
1693 	 * Keep analysing if expandtab is set.
1694 	 */
1695 	if ((!spaces || (!tab_after_sp && spaces < ts)) &&
1696 	    !O_ISSET(sp, O_EXPANDTAB))
1697 		return;
1698 
1699 	/* Count up spaces/tabs needed to get to the target. */
1700 	cno = 0;
1701 	tabs = 0;
1702 	if (!O_ISSET(sp, O_EXPANDTAB)) {
1703 		for (; cno + COL_OFF(cno, ts) <= scno; ++tabs)
1704 			cno += COL_OFF(cno, ts);
1705 	}
1706 	spaces = scno - cno;
1707 
1708 	/*
1709 	 * Figure out how many characters we're dropping -- if we're not
1710 	 * dropping any, it's already minimal, we're done.
1711 	 */
1712 	old = p - tp->lb;
1713 	new = spaces + tabs;
1714 	if (old == new)
1715 		return;
1716 
1717 	/* Shift the rest of the characters down, adjust the counts. */
1718 	del = old - new;
1719 	MEMMOVE(p - del, p, tp->len - old);
1720 	tp->len -= del;
1721 	tp->cno -= del;
1722 
1723 	/* Fill in space/tab characters. */
1724 	for (p = tp->lb; tabs--;)
1725 		*p++ = '\t';
1726 	while (spaces--)
1727 		*p++ = ' ';
1728 	*changedp = 1;
1729 }
1730 
1731 /*
1732  * v_txt_auto --
1733  *	Handle autoindent.  If aitp isn't NULL, use it, otherwise,
1734  *	retrieve the line.
1735  *
1736  * PUBLIC: int v_txt_auto(SCR *, recno_t, TEXT *, size_t, TEXT *);
1737  */
1738 int
1739 v_txt_auto(SCR *sp, recno_t lno, TEXT *aitp, size_t len, TEXT *tp)
1740 {
1741 	size_t nlen;
1742 	CHAR_T *p, *t;
1743 
1744 	if (aitp == NULL) {
1745 		/*
1746 		 * If the ex append command is executed with an address of 0,
1747 		 * it's possible to get here with a line number of 0.  Return
1748 		 * an indent of 0.
1749 		 */
1750 		if (lno == 0) {
1751 			tp->ai = 0;
1752 			return (0);
1753 		}
1754 		if (db_get(sp, lno, DBG_FATAL, &t, &len))
1755 			return (1);
1756 	} else
1757 		t = aitp->lb;
1758 
1759 	/* Count whitespace characters. */
1760 	for (p = t; len > 0; ++p, --len)
1761 		if (!isblank(*p))
1762 			break;
1763 
1764 	/* Set count, check for no indentation. */
1765 	if ((nlen = (p - t)) == 0)
1766 		return (0);
1767 
1768 	/* Make sure the buffer's big enough. */
1769 	BINC_RETW(sp, tp->lb, tp->lb_len, tp->len + nlen);
1770 
1771 	/* Copy the buffer's current contents up. */
1772 	if (tp->len != 0)
1773 		MEMMOVE(tp->lb + nlen, tp->lb, tp->len);
1774 	tp->len += nlen;
1775 
1776 	/* Copy the indentation into the new buffer. */
1777 	MEMMOVE(tp->lb, t, nlen);
1778 
1779 	/* Set the autoindent count. */
1780 	tp->ai = nlen;
1781 	return (0);
1782 }
1783 
1784 /*
1785  * txt_backup --
1786  *	Back up to the previously edited line.
1787  */
1788 static TEXT *
1789 txt_backup(SCR *sp, TEXTH *tiqh, TEXT *tp, u_int32_t *flagsp)
1790 {
1791 	VI_PRIVATE *vip;
1792 	TEXT *ntp;
1793 
1794 	/* Get a handle on the previous TEXT structure. */
1795 	if ((ntp = TAILQ_PREV(tp, _texth, q)) == NULL) {
1796 		if (!FL_ISSET(*flagsp, TXT_REPLAY))
1797 			msgq(sp, M_BERR,
1798 			    "193|Already at the beginning of the insert");
1799 		return (tp);
1800 	}
1801 
1802 	/* Bookkeeping. */
1803 	ntp->len = ntp->sv_len;
1804 
1805 	/* Handle appending to the line. */
1806 	vip = VIP(sp);
1807 	if (ntp->owrite == 0 && ntp->insert == 0) {
1808 		ntp->lb[ntp->len] = CH_CURSOR;
1809 		++ntp->insert;
1810 		++ntp->len;
1811 		FL_SET(*flagsp, TXT_APPENDEOL);
1812 	} else
1813 		FL_CLR(*flagsp, TXT_APPENDEOL);
1814 
1815 	/* Release the current TEXT. */
1816 	TAILQ_REMOVE(tiqh, tp, q);
1817 	text_free(tp);
1818 
1819 	/* Update the old line on the screen. */
1820 	if (vs_change(sp, ntp->lno + 1, LINE_DELETE))
1821 		return (NULL);
1822 
1823 	/* Return the new/current TEXT. */
1824 	return (ntp);
1825 }
1826 
1827 /*
1828  * Text indentation is truly strange.  ^T and ^D do movements to the next or
1829  * previous shiftwidth value, i.e. for a 1-based numbering, with shiftwidth=3,
1830  * ^T moves a cursor on the 7th, 8th or 9th column to the 10th column, and ^D
1831  * moves it back.
1832  *
1833  * !!!
1834  * The ^T and ^D characters in historical vi had special meaning only when they
1835  * were the first characters entered after entering text input mode.  As normal
1836  * erase characters couldn't erase autoindent characters (^T in this case), it
1837  * meant that inserting text into previously existing text was strange -- ^T
1838  * only worked if it was the first keystroke(s), and then could only be erased
1839  * using ^D.  This implementation treats ^T specially anywhere it occurs in the
1840  * input, and permits the standard erase characters to erase the characters it
1841  * inserts.
1842  *
1843  * !!!
1844  * A fun test is to try:
1845  *	:se sw=4 ai list
1846  *	i<CR>^Tx<CR>^Tx<CR>^Tx<CR>^Dx<CR>^Dx<CR>^Dx<esc>
1847  * Historic vi loses some of the '$' marks on the line ends, but otherwise gets
1848  * it right.
1849  *
1850  * XXX
1851  * Technically, txt_dent should be part of the screen interface, as it requires
1852  * knowledge of character sizes, including <space>s, on the screen.  It's here
1853  * because it's a complicated little beast, and I didn't want to shove it down
1854  * into the screen.  It's probable that KEY_COL will call into the screen once
1855  * there are screens with different character representations.
1856  *
1857  * txt_dent --
1858  *	Handle ^T indents, ^D outdents.
1859  *
1860  * If anything changes here, check the ex version to see if it needs similar
1861  * changes.
1862  */
1863 static int
1864 txt_dent(SCR *sp, TEXT *tp, int swopt, int isindent)
1865 {
1866 	CHAR_T ch;
1867 	u_long sw, ts;
1868 	size_t cno, current, spaces, target, tabs;
1869 	int ai_reset;
1870 
1871 	ts = O_VAL(sp, O_TABSTOP);
1872 	sw = O_VAL(sp, swopt);
1873 
1874 	/*
1875 	 * Since we don't know what precedes the character(s) being inserted
1876 	 * (or deleted), the preceding whitespace characters must be resolved.
1877 	 * An example is a <tab>, which doesn't need a full shiftwidth number
1878 	 * of columns because it's preceded by <space>s.  This is easy to get
1879 	 * if the user sets shiftwidth to a value less than tabstop (or worse,
1880 	 * something for which tabstop isn't a multiple) and then uses ^T to
1881 	 * indent, and ^D to outdent.
1882 	 *
1883 	 * Figure out the current and target screen columns.  In the historic
1884 	 * vi, the autoindent column was NOT determined using display widths
1885 	 * of characters as was the wrapmargin column.  For that reason, we
1886 	 * can't use the vs_column() function, but have to calculate it here.
1887 	 * This is slow, but it's normally only on the first few characters of
1888 	 * a line.
1889 	 */
1890 	for (current = cno = 0; cno < tp->cno; ++cno)
1891 		current += tp->lb[cno] == '\t' ?
1892 		    COL_OFF(current, ts) : KEY_COL(sp, tp->lb[cno]);
1893 
1894 	target = current;
1895 	if (isindent)
1896 		target += COL_OFF(target, sw);
1897 	else {
1898 		--target;
1899 		target -= target % sw;
1900 	}
1901 
1902 	/*
1903 	 * The AI characters will be turned into overwrite characters if the
1904 	 * cursor immediately follows them.  We test both the cursor position
1905 	 * and the indent flag because there's no single test.  (^T can only
1906 	 * be detected by the cursor position, and while we know that the test
1907 	 * is always true for ^D, the cursor can be in more than one place, as
1908 	 * "0^D" and "^D" are different.)
1909 	 */
1910 	ai_reset = !isindent || tp->cno == tp->ai + tp->offset;
1911 
1912 	/*
1913 	 * Back up over any previous <blank> characters, changing them into
1914 	 * overwrite characters (including any ai characters).  Then figure
1915 	 * out the current screen column.
1916 	 */
1917 	for (; tp->cno > tp->offset &&
1918 	    (tp->lb[tp->cno - 1] == ' ' || tp->lb[tp->cno - 1] == '\t');
1919 	    --tp->cno, ++tp->owrite);
1920 	for (current = cno = 0; cno < tp->cno; ++cno)
1921 		current += tp->lb[cno] == '\t' ?
1922 		    COL_OFF(current, ts) : KEY_COL(sp, tp->lb[cno]);
1923 
1924 	/*
1925 	 * If we didn't move up to or past the target, it's because there
1926 	 * weren't enough characters to delete, e.g. the first character
1927 	 * of the line was a tp->offset character, and the user entered
1928 	 * ^D to move to the beginning of a line.  An example of this is:
1929 	 *
1930 	 *	:set ai sw=4<cr>i<space>a<esc>i^T^D
1931 	 *
1932 	 * Otherwise, count up the total spaces/tabs needed to get from the
1933 	 * beginning of the line (or the last non-<blank> character) to the
1934 	 * target.
1935 	 */
1936 	if (current >= target)
1937 		spaces = tabs = 0;
1938 	else {
1939 		cno = current;
1940 		tabs = 0;
1941 		if (!O_ISSET(sp, O_EXPANDTAB)) {
1942 			for (; cno + COL_OFF(cno, ts) <= target; ++tabs)
1943 				cno += COL_OFF(cno, ts);
1944 		}
1945 		spaces = target - cno;
1946 	}
1947 
1948 	/* If we overwrote ai characters, reset the ai count. */
1949 	if (ai_reset)
1950 		tp->ai = tabs + spaces;
1951 
1952 	/*
1953 	 * Call txt_insch() to insert each character, so that we get the
1954 	 * correct effect when we add a <tab> to replace N <spaces>.
1955 	 */
1956 	for (ch = '\t'; tabs > 0; --tabs)
1957 		(void)txt_insch(sp, tp, &ch, 0);
1958 	for (ch = ' '; spaces > 0; --spaces)
1959 		(void)txt_insch(sp, tp, &ch, 0);
1960 	return (0);
1961 }
1962 
1963 /*
1964  * txt_fc --
1965  *	File name and ex command completion.
1966  */
1967 static int
1968 txt_fc(SCR *sp, TEXT *tp, int *redrawp)
1969 {
1970 	struct stat sb;
1971 	ARGS **argv;
1972 	EXCMD cmd;
1973 	size_t indx, len, nlen, off;
1974 	int argc;
1975 	CHAR_T *p, *t, *bp;
1976 	char *np, *epd = NULL;
1977 	size_t nplen;
1978 	int fstwd = 1;
1979 
1980 	*redrawp = 0;
1981 	ex_cinit(sp, &cmd, 0, 0, OOBLNO, OOBLNO, 0);
1982 
1983 	/*
1984 	 * Find the beginning of this "word" -- if we're at the beginning
1985 	 * of the line, it's a special case.
1986 	 */
1987 	if (tp->cno == 1) {
1988 		len = 0;
1989 		p = tp->lb;
1990 	} else {
1991 		CHAR_T *ap;
1992 
1993 		for (len = 0,
1994 		    off = MAX(tp->ai, tp->offset), ap = tp->lb + off, p = ap;
1995 		    off < tp->cno; ++off, ++ap) {
1996 			if (IS_ESCAPE(sp, &cmd, *ap)) {
1997 				if (++off == tp->cno)
1998 					break;
1999 				++ap;
2000 				len += 2;
2001 			} else if (cmdskip(*ap)) {
2002 				p = ap + 1;
2003 				if (len > 0)
2004 					fstwd = 0;
2005 				len = 0;
2006 			} else
2007 				++len;
2008 		}
2009 	}
2010 
2011 	/*
2012 	 * If we are at the first word, do ex command completion instead of
2013 	 * file name completion.
2014 	 */
2015 	if (fstwd)
2016 		(void)argv_flt_ex(sp, &cmd, p, len);
2017 	else {
2018 		if ((bp = argv_uesc(sp, &cmd, p, len)) == NULL)
2019 			return (1);
2020 		if (argv_flt_path(sp, &cmd, bp, STRLEN(bp))) {
2021 			FREE_SPACEW(sp, bp, 0);
2022 			return (0);
2023 		}
2024 		FREE_SPACEW(sp, bp, 0);
2025 	}
2026 	argc = cmd.argc;
2027 	argv = cmd.argv;
2028 
2029 	switch (argc) {
2030 	case 0:				/* No matches. */
2031 		(void)sp->gp->scr_bell(sp);
2032 		return (0);
2033 	case 1:				/* One match. */
2034 		/* Always overwrite the old text. */
2035 		nlen = STRLEN(cmd.argv[0]->bp);
2036 		break;
2037 	default:			/* Multiple matches. */
2038 		*redrawp = 1;
2039 		if (txt_fc_col(sp, argc, argv))
2040 			return (1);
2041 
2042 		/* Find the length of the shortest match. */
2043 		for (nlen = cmd.argv[0]->len; --argc > 0;) {
2044 			if (cmd.argv[argc]->len < nlen)
2045 				nlen = cmd.argv[argc]->len;
2046 			for (indx = 0; indx < nlen &&
2047 			    cmd.argv[argc]->bp[indx] == cmd.argv[0]->bp[indx];
2048 			    ++indx);
2049 			nlen = indx;
2050 		}
2051 		break;
2052 	}
2053 
2054 	/* Escape the matched part of the path. */
2055 	if (fstwd)
2056 		bp = cmd.argv[0]->bp;
2057 	else {
2058 		if ((bp = argv_esc(sp, &cmd, cmd.argv[0]->bp, nlen)) == NULL)
2059 			return (1);
2060 		nlen = STRLEN(bp);
2061 	}
2062 
2063 	/* Overwrite the expanded text first. */
2064 	for (t = bp; len > 0 && nlen > 0; --len, --nlen)
2065 		*p++ = *t++;
2066 
2067 	/* If lost text, make the remaining old text overwrite characters. */
2068 	if (len) {
2069 		tp->cno -= len;
2070 		tp->owrite += len;
2071 	}
2072 
2073 	/* Overwrite any overwrite characters next. */
2074 	for (; nlen > 0 && tp->owrite > 0; --nlen, --tp->owrite, ++tp->cno)
2075 		*p++ = *t++;
2076 
2077 	/* Shift remaining text up, and move the cursor to the end. */
2078 	if (nlen) {
2079 		off = p - tp->lb;
2080 		BINC_RETW(sp, tp->lb, tp->lb_len, tp->len + nlen);
2081 		p = tp->lb + off;
2082 
2083 		tp->cno += nlen;
2084 		tp->len += nlen;
2085 
2086 		if (tp->insert != 0)
2087 			(void)MEMMOVE(p + nlen, p, tp->insert);
2088 		while (nlen--)
2089 			*p++ = *t++;
2090 	}
2091 
2092 	if (!fstwd)
2093 		FREE_SPACEW(sp, bp, 0);
2094 
2095 	/* If not a single match of path, we've done. */
2096 	if (argc != 1 || fstwd)
2097 		return (0);
2098 
2099 	/* If a single match and it's a directory, append a '/'. */
2100 	INT2CHAR(sp, cmd.argv[0]->bp, cmd.argv[0]->len + 1, np, nplen);
2101 	if ((epd = expanduser(np)) != NULL)
2102 		np = epd;
2103 	if (!stat(np, &sb) && S_ISDIR(sb.st_mode)) {
2104 		if (tp->owrite == 0) {
2105 			off = p - tp->lb;
2106 			BINC_RETW(sp, tp->lb, tp->lb_len, tp->len + 1);
2107 			p = tp->lb + off;
2108 			if (tp->insert != 0)
2109 				(void)MEMMOVE(p + 1, p, tp->insert);
2110 			++tp->len;
2111 		} else
2112 			--tp->owrite;
2113 
2114 		++tp->cno;
2115 		*p++ = '/';
2116 	}
2117 	free(epd);
2118 	return (0);
2119 }
2120 
2121 /*
2122  * txt_fc_col --
2123  *	Display file names for file name completion.
2124  */
2125 static int
2126 txt_fc_col(SCR *sp, int argc, ARGS **argv)
2127 {
2128 	ARGS **av;
2129 	CHAR_T *p;
2130 	GS *gp;
2131 	size_t base, cnt, col, colwidth, numrows, numcols, prefix, row;
2132 	int ac, nf, reset;
2133 	char *np, *pp;
2134 	size_t nlen;
2135 
2136 	gp = sp->gp;
2137 
2138 	/* Trim any directory prefix common to all of the files. */
2139 	INT2CHAR(sp, argv[0]->bp, argv[0]->len + 1, np, nlen);
2140 	if ((pp = strrchr(np, '/')) == NULL)
2141 		prefix = 0;
2142 	else {
2143 		prefix = (pp - np) + 1;
2144 		for (ac = argc - 1, av = argv + 1; ac > 0; --ac, ++av)
2145 			if (av[0]->len < prefix ||
2146 			    MEMCMP(av[0]->bp, argv[0]->bp,
2147 				   prefix)) {
2148 				prefix = 0;
2149 				break;
2150 			}
2151 	}
2152 
2153 	/*
2154 	 * Figure out the column width for the longest name.  Output is done on
2155 	 * 6 character "tab" boundaries for no particular reason.  (Since we
2156 	 * don't output tab characters, we ignore the terminal's tab settings.)
2157 	 * Ignore the user's tab setting because we have no idea how reasonable
2158 	 * it is.
2159 	 */
2160 	for (ac = argc, av = argv, colwidth = 0; ac > 0; --ac, ++av) {
2161 		for (col = 0, p = av[0]->bp + prefix; *p != '\0'; ++p)
2162 			col += KEY_COL(sp, *p);
2163 		if (col > colwidth)
2164 			colwidth = col;
2165 	}
2166 	colwidth += COL_OFF(colwidth, 6);
2167 
2168 	/*
2169 	 * Writing to the bottom line of the screen is always turned off when
2170 	 * SC_TINPUT_INFO is set.  Turn it back on, we know what we're doing.
2171 	 */
2172 	if (F_ISSET(sp, SC_TINPUT_INFO)) {
2173 		reset = 1;
2174 		F_CLR(sp, SC_TINPUT_INFO);
2175 	} else
2176 		reset = 0;
2177 
2178 #define	CHK_INTR							\
2179 	if (F_ISSET(gp, G_INTERRUPTED))					\
2180 		goto intr;
2181 
2182 	/* If the largest file name is too large, just print them. */
2183 	if (colwidth >= sp->cols) {
2184 		for (ac = argc, av = argv; ac > 0; --ac, ++av) {
2185 			INT2CHAR(sp, av[0]->bp+prefix, av[0]->len+1-prefix,
2186 				 np, nlen);
2187 			pp = msg_print(sp, np, &nf);
2188 			(void)ex_printf(sp, "%s\n", pp);
2189 			if (nf)
2190 				FREE_SPACE(sp, pp, 0);
2191 			if (F_ISSET(gp, G_INTERRUPTED))
2192 				break;
2193 		}
2194 		CHK_INTR;
2195 	} else {
2196 		/* Figure out the number of columns. */
2197 		numcols = (sp->cols - 1) / colwidth;
2198 		if (argc > numcols) {
2199 			numrows = argc / numcols;
2200 			if (argc % numcols)
2201 				++numrows;
2202 		} else
2203 			numrows = 1;
2204 
2205 		/* Display the files in sorted order. */
2206 		for (row = 0; row < numrows; ++row) {
2207 			for (base = row, col = 0; col < numcols; ++col) {
2208 				INT2CHAR(sp, argv[base]->bp+prefix,
2209 					argv[base]->len+1-prefix, np, nlen);
2210 				pp = msg_print(sp, np, &nf);
2211 				cnt = ex_printf(sp, "%s", pp);
2212 				if (nf)
2213 					FREE_SPACE(sp, pp, 0);
2214 				CHK_INTR;
2215 				if ((base += numrows) >= argc)
2216 					break;
2217 				(void)ex_printf(sp,
2218 				    "%*s", (int)(colwidth - cnt), "");
2219 				CHK_INTR;
2220 			}
2221 			(void)ex_puts(sp, "\n");
2222 			CHK_INTR;
2223 		}
2224 		(void)ex_puts(sp, "\n");
2225 		CHK_INTR;
2226 	}
2227 	(void)ex_fflush(sp);
2228 
2229 	if (0) {
2230 intr:		F_CLR(gp, G_INTERRUPTED);
2231 	}
2232 	if (reset)
2233 		F_SET(sp, SC_TINPUT_INFO);
2234 
2235 	return (0);
2236 }
2237 
2238 /*
2239  * txt_emark --
2240  *	Set the end mark on the line.
2241  */
2242 static int
2243 txt_emark(SCR *sp, TEXT *tp, size_t cno)
2244 {
2245 	CHAR_T ch;
2246 	u_char *kp;
2247 	size_t chlen, nlen, olen;
2248 	CHAR_T *p;
2249 
2250 	ch = CH_ENDMARK;
2251 
2252 	/*
2253 	 * The end mark may not be the same size as the current character.
2254 	 * Don't let the line shift.
2255 	 */
2256 	nlen = KEY_COL(sp, ch);
2257 	if (tp->lb[cno] == '\t')
2258 		(void)vs_columns(sp, tp->lb, tp->lno, &cno, &olen);
2259 	else
2260 		olen = KEY_COL(sp, tp->lb[cno]);
2261 
2262 	/*
2263 	 * If the line got longer, well, it's weird, but it's easy.  If
2264 	 * it's the same length, it's easy.  If it got shorter, we have
2265 	 * to fix it up.
2266 	 */
2267 	if (olen > nlen) {
2268 		BINC_RETW(sp, tp->lb, tp->lb_len, tp->len + olen);
2269 		chlen = olen - nlen;
2270 		if (tp->insert != 0)
2271 			MEMMOVE(tp->lb + cno + 1 + chlen,
2272 			    tp->lb + cno + 1, tp->insert);
2273 
2274 		tp->len += chlen;
2275 		tp->owrite += chlen;
2276 		p = tp->lb + cno;
2277 		if (tp->lb[cno] == '\t' ||
2278 		    KEY_NEEDSWIDE(sp, tp->lb[cno]))
2279 			for (cno += chlen; chlen--;)
2280 				*p++ = ' ';
2281 		else
2282 			for (kp = (u_char *)
2283 			    KEY_NAME(sp, tp->lb[cno]),
2284 			    cno += chlen; chlen--;)
2285 				*p++ = *kp++;
2286 	}
2287 	tp->lb[cno] = ch;
2288 	return (vs_change(sp, tp->lno, LINE_RESET));
2289 }
2290 
2291 /*
2292  * txt_err --
2293  *	Handle an error during input processing.
2294  */
2295 static void
2296 txt_err(SCR *sp, TEXTH *tiqh)
2297 {
2298 	recno_t lno;
2299 
2300 	/*
2301 	 * The problem with input processing is that the cursor is at an
2302 	 * indeterminate position since some input may have been lost due
2303 	 * to a malloc error.  So, try to go back to the place from which
2304 	 * the cursor started, knowing that it may no longer be available.
2305 	 *
2306 	 * We depend on at least one line number being set in the text
2307 	 * chain.
2308 	 */
2309 	for (lno = TAILQ_FIRST(tiqh)->lno;
2310 	    !db_exist(sp, lno) && lno > 0; --lno);
2311 
2312 	sp->lno = lno == 0 ? 1 : lno;
2313 	sp->cno = 0;
2314 
2315 	/* Redraw the screen, just in case. */
2316 	F_SET(sp, SC_SCR_REDRAW);
2317 }
2318 
2319 /*
2320  * txt_hex --
2321  *	Let the user insert any character value they want.
2322  *
2323  * !!!
2324  * This is an extension.  The pattern "^X[0-9a-fA-F]*" is a way
2325  * for the user to specify a character value which their keyboard
2326  * may not be able to enter.
2327  */
2328 static int
2329 txt_hex(SCR *sp, TEXT *tp)
2330 {
2331 	CHAR_T savec;
2332 	size_t len, off;
2333 	u_long value;
2334 	CHAR_T *p, *wp;
2335 
2336 	/*
2337 	 * Null-terminate the string.  Since nul isn't a legal hex value,
2338 	 * this should be okay, and lets us use a local routine, which
2339 	 * presumably understands the character set, to convert the value.
2340 	 */
2341 	savec = tp->lb[tp->cno];
2342 	tp->lb[tp->cno] = 0;
2343 
2344 	/* Find the previous CH_HEX character. */
2345 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off, ++len) {
2346 		if (*p == CH_HEX) {
2347 			wp = p + 1;
2348 			break;
2349 		}
2350 		/* Not on this line?  Shouldn't happen. */
2351 		if (off == tp->ai || off == tp->offset)
2352 			goto nothex;
2353 	}
2354 
2355 	/* If length of 0, then it wasn't a hex value. */
2356 	if (len == 0)
2357 		goto nothex;
2358 
2359 	/* Get the value. */
2360 	errno = 0;
2361 	value = STRTOL(wp, NULL, 16);
2362 	if (errno || value > UCHAR_MAX) {
2363 nothex:		tp->lb[tp->cno] = savec;
2364 		return (0);
2365 	}
2366 
2367 	/* Restore the original character. */
2368 	tp->lb[tp->cno] = savec;
2369 
2370 	/* Adjust the bookkeeping. */
2371 	tp->cno -= len;
2372 	tp->len -= len;
2373 	tp->lb[tp->cno - 1] = value;
2374 
2375 	/* Copy down any overwrite characters. */
2376 	if (tp->owrite)
2377 		MEMMOVE(tp->lb + tp->cno, tp->lb + tp->cno + len,
2378 		    tp->owrite);
2379 
2380 	/* Copy down any insert characters. */
2381 	if (tp->insert)
2382 		MEMMOVE(tp->lb + tp->cno + tp->owrite,
2383 		    tp->lb + tp->cno + tp->owrite + len,
2384 		    tp->insert);
2385 
2386 	return (0);
2387 }
2388 
2389 /*
2390  * txt_insch --
2391  *
2392  * !!!
2393  * Historic vi did a special screen optimization for tab characters.  As an
2394  * example, for the keystrokes "iabcd<esc>0C<tab>", the tab overwrote the
2395  * rest of the string when it was displayed.
2396  *
2397  * Because early versions of this implementation redisplayed the entire line
2398  * on each keystroke, the "bcd" was pushed to the right as it ignored that
2399  * the user had "promised" to change the rest of the characters.  However,
2400  * the historic vi implementation had an even worse bug: given the keystrokes
2401  * "iabcd<esc>0R<tab><esc>", the "bcd" disappears, and magically reappears
2402  * on the second <esc> key.
2403  *
2404  * POSIX 1003.2 requires (will require) that this be fixed, specifying that
2405  * vi overwrite characters the user has committed to changing, on the basis
2406  * of the screen space they require, but that it not overwrite other characters.
2407  */
2408 static int
2409 txt_insch(SCR *sp, TEXT *tp, CHAR_T *chp, u_int flags)
2410 {
2411 	u_char *kp;
2412 	CHAR_T savech;
2413 	size_t chlen, cno, copydown, olen, nlen;
2414 	CHAR_T *p;
2415 
2416 	/*
2417 	 * The 'R' command does one-for-one replacement, because there's
2418 	 * no way to know how many characters the user intends to replace.
2419 	 */
2420 	if (LF_ISSET(TXT_REPLACE)) {
2421 		if (tp->owrite) {
2422 			--tp->owrite;
2423 			tp->lb[tp->cno++] = *chp;
2424 			return (0);
2425 		}
2426 	} else if (tp->owrite) {		/* Overwrite a character. */
2427 		cno = tp->cno;
2428 
2429 		/*
2430 		 * If the old or new characters are tabs, then the length of the
2431 		 * display depends on the character position in the display.  We
2432 		 * don't even try to handle this here, just ask the screen.
2433 		 */
2434 		if (*chp == '\t') {
2435 			savech = tp->lb[cno];
2436 			tp->lb[cno] = '\t';
2437 			(void)vs_columns(sp, tp->lb, tp->lno, &cno, &nlen);
2438 			tp->lb[cno] = savech;
2439 		} else
2440 			nlen = KEY_COL(sp, *chp);
2441 
2442 		/*
2443 		 * Eat overwrite characters until we run out of them or we've
2444 		 * handled the length of the new character.  If we only eat
2445 		 * part of an overwrite character, break it into its component
2446 		 * elements and display the remaining components.
2447 		 */
2448 		for (copydown = 0; nlen != 0 && tp->owrite != 0;) {
2449 			--tp->owrite;
2450 
2451 			if (tp->lb[cno] == '\t')
2452 				(void)vs_columns(sp,
2453 				    tp->lb, tp->lno, &cno, &olen);
2454 			else
2455 				olen = KEY_COL(sp, tp->lb[cno]);
2456 
2457 			if (olen == nlen) {
2458 				nlen = 0;
2459 				break;
2460 			}
2461 			if (olen < nlen) {
2462 				++copydown;
2463 				nlen -= olen;
2464 			} else {
2465 				BINC_RETW(sp,
2466 				    tp->lb, tp->lb_len, tp->len + olen);
2467 				chlen = olen - nlen;
2468 				MEMMOVE(tp->lb + cno + 1 + chlen,
2469 				    tp->lb + cno + 1,
2470 				    tp->owrite + tp->insert);
2471 
2472 				tp->len += chlen;
2473 				tp->owrite += chlen;
2474 				if (tp->lb[cno] == '\t' ||
2475 				   KEY_NEEDSWIDE(sp, tp->lb[cno]))
2476 					for (p = tp->lb + cno + 1; chlen--;)
2477 						*p++ = ' ';
2478 				else
2479 					for (kp = (u_char *)
2480 					    KEY_NAME(sp, tp->lb[cno]) + nlen,
2481 					    p = tp->lb + cno + 1; chlen--;)
2482 						*p++ = *kp++;
2483 				nlen = 0;
2484 				break;
2485 			}
2486 		}
2487 
2488 		/*
2489 		 * If had to erase several characters, we adjust the total
2490 		 * count, and if there are any characters left, shift them
2491 		 * into position.
2492 		 */
2493 		if (copydown != 0 && (tp->len -= copydown) != 0)
2494 			MEMMOVE(tp->lb + cno, tp->lb + cno + copydown,
2495 			    tp->owrite + tp->insert + copydown);
2496 
2497 		/* If we had enough overwrite characters, we're done. */
2498 		if (nlen == 0) {
2499 			tp->lb[tp->cno++] = *chp;
2500 			return (0);
2501 		}
2502 	}
2503 
2504 	/* Check to see if the character fits into the input buffer. */
2505 	BINC_RETW(sp, tp->lb, tp->lb_len, tp->len + 1);
2506 
2507 	++tp->len;
2508 	if (tp->insert) {			/* Insert a character. */
2509 		if (tp->insert == 1)
2510 			tp->lb[tp->cno + 1] = tp->lb[tp->cno];
2511 		else
2512 			MEMMOVE(tp->lb + tp->cno + 1,
2513 			    tp->lb + tp->cno, tp->owrite + tp->insert);
2514 	}
2515 	tp->lb[tp->cno++] = *chp;
2516 	return (0);
2517 }
2518 
2519 /*
2520  * txt_isrch --
2521  *	Do an incremental search.
2522  */
2523 static int
2524 txt_isrch(SCR *sp, VICMD *vp, TEXT *tp, u_int8_t *is_flagsp)
2525 {
2526 	MARK start;
2527 	recno_t lno;
2528 	u_int sf;
2529 
2530 	/* If it's a one-line screen, we don't do incrementals. */
2531 	if (IS_ONELINE(sp)) {
2532 		FL_CLR(*is_flagsp, IS_RUNNING);
2533 		return (0);
2534 	}
2535 
2536 	/*
2537 	 * If the user erases back to the beginning of the buffer, there's
2538 	 * nothing to search for.  Reset the cursor to the starting point.
2539 	 */
2540 	if (tp->cno <= 1) {
2541 		vp->m_final = vp->m_start;
2542 		return (0);
2543 	}
2544 
2545 	/*
2546 	 * If it's an RE quote character, and not quoted, ignore it until
2547 	 * we get another character.
2548 	 */
2549 	if (tp->lb[tp->cno - 1] == '\\' &&
2550 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
2551 		return (0);
2552 
2553 	/*
2554 	 * If it's a magic shell character, and not quoted, reset the cursor
2555 	 * to the starting point.
2556 	 */
2557 	if (IS_SHELLMETA(sp, tp->lb[tp->cno - 1]) &&
2558 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
2559 		vp->m_final = vp->m_start;
2560 
2561 	/*
2562 	 * If we see the search pattern termination character, then quit doing
2563 	 * an incremental search.  There may be more, e.g., ":/foo/;/bar/",
2564 	 * and we can't handle that incrementally.  Also, reset the cursor to
2565 	 * the original location, the ex search routines don't know anything
2566 	 * about incremental searches.
2567 	 */
2568 	if (tp->lb[0] == tp->lb[tp->cno - 1] &&
2569 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\')) {
2570 		vp->m_final = vp->m_start;
2571 		FL_CLR(*is_flagsp, IS_RUNNING);
2572 		return (0);
2573 	}
2574 
2575 	/*
2576 	 * Remember the input line and discard the special input map,
2577 	 * but don't overwrite the input line on the screen.
2578 	 */
2579 	lno = tp->lno;
2580 	F_SET(VIP(sp), VIP_S_MODELINE);
2581 	F_CLR(sp, SC_TINPUT | SC_TINPUT_INFO);
2582 	if (txt_map_end(sp))
2583 		return (1);
2584 
2585 	/*
2586 	 * Specify a starting point and search.  If we find a match, move to
2587 	 * it and refresh the screen.  If we didn't find the match, then we
2588 	 * beep the screen.  When searching from the original cursor position,
2589 	 * we have to move the cursor, otherwise, we don't want to move the
2590 	 * cursor in case the text at the current position continues to match.
2591 	 */
2592 	if (FL_ISSET(*is_flagsp, IS_RESTART)) {
2593 		start = vp->m_start;
2594 		sf = SEARCH_SET;
2595 	} else {
2596 		start = vp->m_final;
2597 		sf = SEARCH_INCR | SEARCH_SET;
2598 	}
2599 
2600 	if (tp->lb[0] == '/' ?
2601 	    !f_search(sp,
2602 	    &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf) :
2603 	    !b_search(sp,
2604 	    &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf)) {
2605 		sp->lno = vp->m_final.lno;
2606 		sp->cno = vp->m_final.cno;
2607 		FL_CLR(*is_flagsp, IS_RESTART);
2608 
2609 		if (!KEYS_WAITING(sp) && vs_refresh(sp, 0))
2610 			return (1);
2611 	} else
2612 		FL_SET(*is_flagsp, IS_RESTART);
2613 
2614 	/* Reinstantiate the special input map. */
2615 	if (txt_map_init(sp))
2616 		return (1);
2617 	F_CLR(VIP(sp), VIP_S_MODELINE);
2618 	F_SET(sp, SC_TINPUT | SC_TINPUT_INFO);
2619 
2620 	/* Reset the line number of the input line. */
2621 	tp->lno = TMAP[0].lno;
2622 
2623 	/*
2624 	 * If the colon command-line moved, i.e. the screen scrolled,
2625 	 * refresh the input line.
2626 	 *
2627 	 * XXX
2628 	 * We shouldn't be calling vs_line, here -- we need dirty bits
2629 	 * on entries in the SMAP array.
2630 	 */
2631 	if (lno != TMAP[0].lno) {
2632 		if (vs_line(sp, &TMAP[0], NULL, NULL))
2633 			return (1);
2634 		(void)sp->gp->scr_refresh(sp, 0);
2635 	}
2636 	return (0);
2637 }
2638 
2639 /*
2640  * txt_resolve --
2641  *	Resolve the input text chain into the file.
2642  */
2643 static int
2644 txt_resolve(SCR *sp, TEXTH *tiqh, u_int32_t flags)
2645 {
2646 	VI_PRIVATE *vip;
2647 	TEXT *tp;
2648 	recno_t lno;
2649 	int changed;
2650 
2651 	/*
2652 	 * The first line replaces a current line, and all subsequent lines
2653 	 * are appended into the file.  Resolve autoindented characters for
2654 	 * each line before committing it.  If the latter causes the line to
2655 	 * change, we have to redisplay it, otherwise the information cached
2656 	 * about the line will be wrong.
2657 	 */
2658 	vip = VIP(sp);
2659 	tp = TAILQ_FIRST(tiqh);
2660 
2661 	if (LF_ISSET(TXT_AUTOINDENT))
2662 		txt_ai_resolve(sp, tp, &changed);
2663 	else
2664 		changed = 0;
2665 	if (db_set(sp, tp->lno, tp->lb, tp->len) ||
2666 	    (changed && vs_change(sp, tp->lno, LINE_RESET)))
2667 		return (1);
2668 
2669 	for (lno = tp->lno; (tp = TAILQ_NEXT(tp, q)) != NULL; ++lno) {
2670 		if (LF_ISSET(TXT_AUTOINDENT))
2671 			txt_ai_resolve(sp, tp, &changed);
2672 		else
2673 			changed = 0;
2674 		if (db_append(sp, 0, lno, tp->lb, tp->len) ||
2675 		    (changed && vs_change(sp, tp->lno, LINE_RESET)))
2676 			return (1);
2677 	}
2678 
2679 	/*
2680 	 * Clear the input flag, the look-aside buffer is no longer valid.
2681 	 * Has to be done as part of text resolution, or upon return we'll
2682 	 * be looking at incorrect data.
2683 	 */
2684 	F_CLR(sp, SC_TINPUT);
2685 
2686 	return (0);
2687 }
2688 
2689 /*
2690  * txt_showmatch --
2691  *	Show a character match.
2692  *
2693  * !!!
2694  * Historic vi tried to display matches even in the :colon command line.
2695  * I think not.
2696  */
2697 static int
2698 txt_showmatch(SCR *sp, TEXT *tp)
2699 {
2700 	GS *gp;
2701 	VCS cs;
2702 	MARK m;
2703 	int cnt, endc, startc;
2704 
2705 	gp = sp->gp;
2706 
2707 	/*
2708 	 * Do a refresh first, in case we haven't done one in awhile,
2709 	 * so the user can see what we're complaining about.
2710 	 */
2711 	UPDATE_POSITION(sp, tp);
2712 	if (vs_refresh(sp, 1))
2713 		return (1);
2714 
2715 	/*
2716 	 * We don't display the match if it's not on the screen.  Find
2717 	 * out what the first character on the screen is.
2718 	 */
2719 	if (vs_sm_position(sp, &m, 0, P_TOP))
2720 		return (1);
2721 
2722 	/* Initialize the getc() interface. */
2723 	cs.cs_lno = tp->lno;
2724 	cs.cs_cno = tp->cno - 1;
2725 	if (cs_init(sp, &cs))
2726 		return (1);
2727 	startc = STRCHR(VIP(sp)->mcs, endc = cs.cs_ch)[-1];
2728 
2729 	/* Search for the match. */
2730 	for (cnt = 1;;) {
2731 		if (cs_prev(sp, &cs))
2732 			return (1);
2733 		if (cs.cs_flags != 0) {
2734 			if (cs.cs_flags == CS_EOF || cs.cs_flags == CS_SOF) {
2735 				msgq(sp, M_BERR,
2736 				    "Unmatched %s", KEY_NAME(sp, endc));
2737 				return (0);
2738 			}
2739 			continue;
2740 		}
2741 		if (cs.cs_ch == endc)
2742 			++cnt;
2743 		else if (cs.cs_ch == startc && --cnt == 0)
2744 			break;
2745 	}
2746 
2747 	/* If the match is on the screen, move to it. */
2748 	if (cs.cs_lno < m.lno || (cs.cs_lno == m.lno && cs.cs_cno < m.cno))
2749 		return (0);
2750 	sp->lno = cs.cs_lno;
2751 	sp->cno = cs.cs_cno;
2752 	if (vs_refresh(sp, 1))
2753 		return (1);
2754 
2755 	/* Wait for timeout or character arrival. */
2756 	return (v_event_get(sp,
2757 	    NULL, O_VAL(sp, O_MATCHTIME) * 100, EC_TIMEOUT));
2758 }
2759 
2760 /*
2761  * txt_margin --
2762  *	Handle margin wrap.
2763  */
2764 static int
2765 txt_margin(SCR *sp, TEXT *tp, TEXT *wmtp, int *didbreak, u_int32_t flags)
2766 {
2767 	VI_PRIVATE *vip;
2768 	size_t len, off;
2769 	CHAR_T *p, *wp;
2770 
2771 	/* Find the nearest previous blank. */
2772 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --off, --p, ++len) {
2773 		if (isblank(*p)) {
2774 			wp = p + 1;
2775 			break;
2776 		}
2777 
2778 		/*
2779 		 * If reach the start of the line, there's nowhere to break.
2780 		 *
2781 		 * !!!
2782 		 * Historic vi belled each time a character was entered after
2783 		 * crossing the margin until a space was entered which could
2784 		 * be used to break the line.  I don't as it tends to wake the
2785 		 * cats.
2786 		 */
2787 		if (off == tp->ai || off == tp->offset) {
2788 			*didbreak = 0;
2789 			return (0);
2790 		}
2791 	}
2792 
2793 	/*
2794 	 * Store saved information about the rest of the line in the
2795 	 * wrapmargin TEXT structure.
2796 	 *
2797 	 * !!!
2798 	 * The offset field holds the length of the current characters
2799 	 * that the user entered, but which are getting split to the new
2800 	 * line -- it's going to be used to set the cursor value when we
2801 	 * move to the new line.
2802 	 */
2803 	vip = VIP(sp);
2804 	wmtp->lb = p + 1;
2805 	wmtp->offset = len;
2806 	wmtp->insert = LF_ISSET(TXT_APPENDEOL) ?  tp->insert - 1 : tp->insert;
2807 	wmtp->owrite = tp->owrite;
2808 
2809 	/* Correct current bookkeeping information. */
2810 	tp->cno -= len;
2811 	if (LF_ISSET(TXT_APPENDEOL)) {
2812 		tp->len -= len + tp->owrite + (tp->insert - 1);
2813 		tp->insert = 1;
2814 	} else {
2815 		tp->len -= len + tp->owrite + tp->insert;
2816 		tp->insert = 0;
2817 	}
2818 	tp->owrite = 0;
2819 
2820 	/*
2821 	 * !!!
2822 	 * Delete any trailing whitespace from the current line.
2823 	 */
2824 	for (;; --p, --off) {
2825 		if (!isblank(*p))
2826 			break;
2827 		--tp->cno;
2828 		--tp->len;
2829 		if (off == tp->ai || off == tp->offset)
2830 			break;
2831 	}
2832 	*didbreak = 1;
2833 	return (0);
2834 }
2835 
2836 /*
2837  * txt_Rresolve --
2838  *	Resolve the input line for the 'R' command.
2839  */
2840 static void
2841 txt_Rresolve(SCR *sp, TEXTH *tiqh, TEXT *tp, const size_t orig_len)
2842 {
2843 	TEXT *ttp;
2844 	size_t input_len, retain;
2845 	CHAR_T *p;
2846 
2847 	/*
2848 	 * Check to make sure that the cursor hasn't moved beyond
2849 	 * the end of the line.
2850 	 */
2851 	if (tp->owrite == 0)
2852 		return;
2853 
2854 	/*
2855 	 * Calculate how many characters the user has entered,
2856 	 * plus the blanks erased by <carriage-return>/<newline>s.
2857 	 */
2858 	for (ttp = TAILQ_FIRST(tiqh), input_len = 0;;) {
2859 		input_len += ttp == tp ? tp->cno : ttp->len + ttp->R_erase;
2860 		if ((ttp = TAILQ_NEXT(ttp, q)) == NULL)
2861 			break;
2862 	}
2863 
2864 	/*
2865 	 * If the user has entered less characters than the original line
2866 	 * was long, restore any overwriteable characters to the original
2867 	 * characters.  These characters are entered as "insert characters",
2868 	 * because they're after the cursor and we don't want to lose them.
2869 	 * (This is okay because the R command has no insert characters.)
2870 	 * We set owrite to 0 so that the insert characters don't get copied
2871 	 * to somewhere else, which means that the line and the length have
2872 	 * to be adjusted here as well.
2873 	 *
2874 	 * We have to retrieve the original line because the original pinned
2875 	 * page has long since been discarded.  If it doesn't exist, that's
2876 	 * okay, the user just extended the file.
2877 	 */
2878 	if (input_len < orig_len) {
2879 		retain = MIN(tp->owrite, orig_len - input_len);
2880 		if (db_get(sp,
2881 		    TAILQ_FIRST(tiqh)->lno, DBG_FATAL | DBG_NOCACHE, &p, NULL))
2882 			return;
2883 		MEMCPY(tp->lb + tp->cno, p + input_len, retain);
2884 		tp->len -= tp->owrite - retain;
2885 		tp->owrite = 0;
2886 		tp->insert += retain;
2887 	}
2888 }
2889 
2890 /*
2891  * txt_nomorech --
2892  *	No more characters message.
2893  */
2894 static void
2895 txt_nomorech(SCR *sp)
2896 {
2897 	msgq(sp, M_BERR, "194|No more characters to erase");
2898 }
2899