xref: /openbsd-src/usr.bin/cvs/rcs.c (revision 11efff7f3ac2b3cfeff0c0cddc14294d9b3aca4f)
1 /*	$OpenBSD: rcs.c,v 1.19 2004/12/18 17:20:40 jfb Exp $	*/
2 /*
3  * Copyright (c) 2004 Jean-Francois Brousseau <jfb@openbsd.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/queue.h>
29 #include <sys/stat.h>
30 
31 #include <errno.h>
32 #include <stdio.h>
33 #include <ctype.h>
34 #include <stdlib.h>
35 #include <string.h>
36 
37 #include "rcs.h"
38 #include "log.h"
39 
40 #define RCS_BUFSIZE     16384
41 #define RCS_BUFEXTSIZE   8192
42 
43 
44 /* RCS token types */
45 #define RCS_TOK_ERR     -1
46 #define RCS_TOK_EOF      0
47 #define RCS_TOK_NUM      1
48 #define RCS_TOK_ID       2
49 #define RCS_TOK_STRING   3
50 #define RCS_TOK_SCOLON   4
51 #define RCS_TOK_COLON    5
52 
53 
54 #define RCS_TOK_HEAD     8
55 #define RCS_TOK_BRANCH   9
56 #define RCS_TOK_ACCESS   10
57 #define RCS_TOK_SYMBOLS  11
58 #define RCS_TOK_LOCKS    12
59 #define RCS_TOK_COMMENT  13
60 #define RCS_TOK_EXPAND   14
61 #define RCS_TOK_DATE     15
62 #define RCS_TOK_AUTHOR   16
63 #define RCS_TOK_STATE    17
64 #define RCS_TOK_NEXT     18
65 #define RCS_TOK_BRANCHES 19
66 #define RCS_TOK_DESC     20
67 #define RCS_TOK_LOG      21
68 #define RCS_TOK_TEXT     22
69 #define RCS_TOK_STRICT   23
70 
71 #define RCS_ISKEY(t)    (((t) >= RCS_TOK_HEAD) && ((t) <= RCS_TOK_BRANCHES))
72 
73 
74 #define RCS_NOSCOL   0x01   /* no terminating semi-colon */
75 #define RCS_VOPT     0x02   /* value is optional */
76 
77 
78 /* opaque parse data */
79 struct rcs_pdata {
80 	u_int  rp_lines;
81 
82 	char  *rp_buf;
83 	size_t rp_blen;
84 	char  *rp_bufend;
85 
86 	/* pushback token buffer */
87 	char   rp_ptok[128];
88 	int    rp_pttype;       /* token type, RCS_TOK_ERR if no token */
89 
90 	FILE  *rp_file;
91 };
92 
93 
94 struct rcs_line {
95 	char *rl_line;
96 	int   rl_lineno;
97 	TAILQ_ENTRY(rcs_line) rl_list;
98 };
99 TAILQ_HEAD(rcs_tqh, rcs_line);
100 
101 struct rcs_foo {
102 	int       rl_nblines;
103 	char     *rl_data;
104 	struct rcs_tqh rl_lines;
105 };
106 
107 static int  rcs_parse_admin     (RCSFILE *);
108 static int  rcs_parse_delta     (RCSFILE *);
109 static int  rcs_parse_deltatext (RCSFILE *);
110 
111 static int      rcs_parse_access    (RCSFILE *);
112 static int      rcs_parse_symbols   (RCSFILE *);
113 static int      rcs_parse_locks     (RCSFILE *);
114 static int      rcs_parse_branches  (RCSFILE *, struct rcs_delta *);
115 static void     rcs_freedelta       (struct rcs_delta *);
116 static void     rcs_freepdata       (struct rcs_pdata *);
117 static int      rcs_gettok          (RCSFILE *);
118 static int      rcs_pushtok         (RCSFILE *, const char *, int);
119 static int      rcs_growbuf         (RCSFILE *);
120 static int      rcs_patch_lines     (struct rcs_foo *, struct rcs_foo *);
121 
122 static struct rcs_delta*  rcs_findrev    (RCSFILE *, RCSNUM *);
123 static struct rcs_foo*    rcs_splitlines (const char *);
124 static void               rcs_freefoo    (struct rcs_foo *);
125 
126 #define RCS_TOKSTR(rfp)   ((struct rcs_pdata *)rfp->rf_pdata)->rp_buf
127 #define RCS_TOKLEN(rfp)   ((struct rcs_pdata *)rfp->rf_pdata)->rp_blen
128 
129 
130 static struct rcs_key {
131 	char  rk_str[16];
132 	int   rk_id;
133 	int   rk_val;
134 	int   rk_flags;
135 } rcs_keys[] = {
136 	{ "access",   RCS_TOK_ACCESS,   RCS_TOK_ID,     RCS_VOPT     },
137 	{ "author",   RCS_TOK_AUTHOR,   RCS_TOK_STRING, 0            },
138 	{ "branch",   RCS_TOK_BRANCH,   RCS_TOK_NUM,    RCS_VOPT     },
139 	{ "branches", RCS_TOK_BRANCHES, RCS_TOK_NUM,    RCS_VOPT     },
140 	{ "comment",  RCS_TOK_COMMENT,  RCS_TOK_STRING, RCS_VOPT     },
141 	{ "date",     RCS_TOK_DATE,     RCS_TOK_NUM,    0            },
142 	{ "desc",     RCS_TOK_DESC,     RCS_TOK_STRING, RCS_NOSCOL   },
143 	{ "expand",   RCS_TOK_EXPAND,   RCS_TOK_STRING, RCS_VOPT     },
144 	{ "head",     RCS_TOK_HEAD,     RCS_TOK_NUM,    RCS_VOPT     },
145 	{ "locks",    RCS_TOK_LOCKS,    RCS_TOK_ID,     0            },
146 	{ "log",      RCS_TOK_LOG,      RCS_TOK_STRING, RCS_NOSCOL   },
147 	{ "next",     RCS_TOK_NEXT,     RCS_TOK_NUM,    RCS_VOPT     },
148 	{ "state",    RCS_TOK_STATE,    RCS_TOK_STRING, RCS_VOPT     },
149 	{ "strict",   RCS_TOK_STRICT,   0,              0,           },
150 	{ "symbols",  RCS_TOK_SYMBOLS,  0,              0            },
151 	{ "text",     RCS_TOK_TEXT,     RCS_TOK_STRING, RCS_NOSCOL   },
152 };
153 
154 #define RCS_NKEYS   (sizeof(rcs_keys)/sizeof(rcs_keys[0]))
155 
156 
157 /*
158  * rcs_open()
159  *
160  * Open a file containing RCS-formatted information.  The file's path is
161  * given in <path>, and the opening mode is given in <mode>, which is either
162  * RCS_MODE_READ, RCS_MODE_WRITE, or RCS_MODE_RDWR.  If the mode requests write
163  * access and the file does not exist, it will be created.
164  * The file isn't actually parsed by rcs_open(); parsing is delayed until the
165  * first operation that requires information from the file.
166  * Returns a handle to the opened file on success, or NULL on failure.
167  */
168 RCSFILE*
169 rcs_open(const char *path, u_int mode)
170 {
171 	RCSFILE *rfp;
172 	struct stat st;
173 
174 	if ((stat(path, &st) == -1) && (errno == ENOENT) &&
175 	   !(mode & RCS_MODE_WRITE)) {
176 		cvs_log(LP_ERRNO, "cannot open RCS file `%s'", path);
177 		return (NULL);
178 	}
179 
180 	rfp = (RCSFILE *)malloc(sizeof(*rfp));
181 	if (rfp == NULL) {
182 		cvs_log(LP_ERRNO, "failed to allocate RCS file structure");
183 		return (NULL);
184 	}
185 	memset(rfp, 0, sizeof(*rfp));
186 
187 	rfp->rf_head = rcsnum_alloc();
188 	if (rfp->rf_head == NULL) {
189 		free(rfp);
190 		return (NULL);
191 	}
192 
193 	rfp->rf_branch = rcsnum_alloc();
194 	if (rfp->rf_branch == NULL) {
195 		rcs_close(rfp);
196 		return (NULL);
197 	}
198 
199 	rfp->rf_path = strdup(path);
200 	if (rfp->rf_path == NULL) {
201 		cvs_log(LP_ERRNO, "failed to duplicate RCS file path");
202 		rcs_close(rfp);
203 		return (NULL);
204 	}
205 
206 	rcsnum_aton(RCS_HEAD_INIT, NULL, rfp->rf_head);
207 
208 	rfp->rf_ref = 1;
209 	rfp->rf_flags |= RCS_RF_SLOCK;
210 	rfp->rf_mode = mode;
211 
212 	TAILQ_INIT(&(rfp->rf_delta));
213 	TAILQ_INIT(&(rfp->rf_symbols));
214 	TAILQ_INIT(&(rfp->rf_locks));
215 
216 	if (rcs_parse(rfp) < 0) {
217 		rcs_close(rfp);
218 		return (NULL);
219 	}
220 
221 	return (rfp);
222 }
223 
224 
225 /*
226  * rcs_close()
227  *
228  * Close an RCS file handle.
229  */
230 void
231 rcs_close(RCSFILE *rfp)
232 {
233 	struct rcs_delta *rdp;
234 	struct rcs_lock *rlp;
235 	struct rcs_sym *rsp;
236 
237 	if (rfp->rf_ref > 1) {
238 		rfp->rf_ref--;
239 		return;
240 	}
241 
242 	while (!TAILQ_EMPTY(&(rfp->rf_delta))) {
243 		rdp = TAILQ_FIRST(&(rfp->rf_delta));
244 		TAILQ_REMOVE(&(rfp->rf_delta), rdp, rd_list);
245 		rcs_freedelta(rdp);
246 	}
247 
248 	while (!TAILQ_EMPTY(&(rfp->rf_symbols))) {
249 		rsp = TAILQ_FIRST(&(rfp->rf_symbols));
250 		TAILQ_REMOVE(&(rfp->rf_symbols), rsp, rs_list);
251 		rcsnum_free(rsp->rs_num);
252 		free(rsp->rs_name);
253 		free(rsp);
254 	}
255 
256 	while (!TAILQ_EMPTY(&(rfp->rf_locks))) {
257 		rlp = TAILQ_FIRST(&(rfp->rf_locks));
258 		TAILQ_REMOVE(&(rfp->rf_locks), rlp, rl_list);
259 		rcsnum_free(rlp->rl_num);
260 		free(rlp);
261 	}
262 
263 	if (rfp->rf_head != NULL)
264 		rcsnum_free(rfp->rf_head);
265 	if (rfp->rf_branch != NULL)
266 		rcsnum_free(rfp->rf_branch);
267 
268 	if (rfp->rf_path != NULL)
269 		free(rfp->rf_path);
270 	if (rfp->rf_comment != NULL)
271 		free(rfp->rf_comment);
272 	if (rfp->rf_expand != NULL)
273 		free(rfp->rf_expand);
274 	if (rfp->rf_desc != NULL)
275 		free(rfp->rf_desc);
276 	free(rfp);
277 }
278 
279 
280 /*
281  * rcs_write()
282  *
283  * Write the contents of the RCS file handle <rfp> to disk in the file whose
284  * path is in <rf_path>.
285  * Returns 0 on success, or -1 on failure.
286  */
287 int
288 rcs_write(RCSFILE *rfp)
289 {
290 	FILE *fp;
291 	char buf[1024], numbuf[64], *cp;
292 	size_t rlen, len;
293 	struct rcs_sym *symp;
294 	struct rcs_delta *rdp;
295 
296 	if (rfp->rf_flags & RCS_RF_SYNCED)
297 		return (0);
298 
299 	fp = fopen(rfp->rf_path, "w");
300 	if (fp == NULL) {
301 		cvs_log(LP_ERRNO, "failed to open RCS output file `%s'",
302 		    rfp->rf_path);
303 		return (-1);
304 	}
305 
306 	rcsnum_tostr(rfp->rf_head, numbuf, sizeof(numbuf));
307 	fprintf(fp, "head\t%s;\n", numbuf);
308 	fprintf(fp, "access;\n");
309 
310 	fprintf(fp, "symbols\n");
311 	TAILQ_FOREACH(symp, &(rfp->rf_symbols), rs_list) {
312 		rcsnum_tostr(symp->rs_num, numbuf, sizeof(numbuf));
313 		snprintf(buf, sizeof(buf), "%s:%s", symp->rs_name, numbuf);
314 		fprintf(fp, "\t%s", buf);
315 		if (symp != TAILQ_LAST(&(rfp->rf_symbols), rcs_slist))
316 			fputc('\n', fp);
317 	}
318 	fprintf(fp, ";\n");
319 
320 	fprintf(fp, "locks;");
321 
322 	if (rfp->rf_flags & RCS_RF_SLOCK)
323 		fprintf(fp, " strict;");
324 	fputc('\n', fp);
325 
326 	if (rfp->rf_comment != NULL)
327 		fprintf(fp, "comment\t@%s@;\n", rfp->rf_comment);
328 
329 	if (rfp->rf_expand != NULL)
330 		fprintf(fp, "expand @ %s @;\n", rfp->rf_expand);
331 
332 	fprintf(fp, "\n\n");
333 
334 	TAILQ_FOREACH(rdp, &(rfp->rf_delta), rd_list) {
335 		fprintf(fp, "%s\n", rcsnum_tostr(rdp->rd_num, numbuf,
336 		    sizeof(numbuf)));
337 		fprintf(fp, "date\t%d.%02d.%02d.%02d.%02d.%02d;",
338 		    rdp->rd_date.tm_year, rdp->rd_date.tm_mon + 1,
339 		    rdp->rd_date.tm_mday, rdp->rd_date.tm_hour,
340 		    rdp->rd_date.tm_min, rdp->rd_date.tm_sec);
341 		fprintf(fp, "\tauthor %s;\tstate %s;\n",
342 		    rdp->rd_author, rdp->rd_state);
343 		fprintf(fp, "branches;\n");
344 		fprintf(fp, "next\t%s;\n\n", rcsnum_tostr(rdp->rd_next,
345 		    numbuf, sizeof(numbuf)));
346 	}
347 
348 	fprintf(fp, "\ndesc\n@%s@\n\n", rfp->rf_desc);
349 
350 	/* deltatexts */
351 	TAILQ_FOREACH(rdp, &(rfp->rf_delta), rd_list) {
352 		fprintf(fp, "\n%s\n", rcsnum_tostr(rdp->rd_num, numbuf,
353 		    sizeof(numbuf)));
354 		fprintf(fp, "log\n@%s@\ntext\n@", rdp->rd_log);
355 
356 		cp = rdp->rd_text;
357 		do {
358 			len = sizeof(buf);
359 			rlen = rcs_stresc(1, cp, buf, &len);
360 			fprintf(fp, "%s", buf);
361 			cp += rlen;
362 		} while (len != 0);
363 		fprintf(fp, "@\n\n");
364 	}
365 	fclose(fp);
366 
367 	rfp->rf_flags |= RCS_RF_SYNCED;
368 
369 	return (0);
370 }
371 
372 
373 /*
374  * rcs_addsym()
375  *
376  * Add a symbol to the list of symbols for the RCS file <rfp>.  The new symbol
377  * is named <sym> and is bound to the RCS revision <snum>.
378  * Returns 0 on success, or -1 on failure.
379  */
380 int
381 rcs_addsym(RCSFILE *rfp, const char *sym, RCSNUM *snum)
382 {
383 	struct rcs_sym *symp;
384 
385 	/* first look for duplication */
386 	TAILQ_FOREACH(symp, &(rfp->rf_symbols), rs_list) {
387 		if (strcmp(symp->rs_name, sym) == 0) {
388 			cvs_log(LP_ERR, "attempt to add duplicate symbol `%s'",
389 			    sym);
390 			return (-1);
391 		}
392 	}
393 
394 	symp = (struct rcs_sym *)malloc(sizeof(*symp));
395 	if (symp == NULL) {
396 		cvs_log(LP_ERRNO, "failed to allocate RCS symbol");
397 		return (-1);
398 	}
399 
400 	symp->rs_name = strdup(sym);
401 	if (symp->rs_name == NULL) {
402 		cvs_log(LP_ERRNO, "failed to duplicate symbol");
403 		free(symp);
404 		return (-1);
405 	}
406 
407 	symp->rs_num = rcsnum_alloc();
408 	if (symp->rs_num == NULL) {
409 		free(symp->rs_name);
410 		free(symp);
411 		return (-1);
412 	}
413 	rcsnum_cpy(snum, symp->rs_num, 0);
414 
415 	TAILQ_INSERT_HEAD(&(rfp->rf_symbols), symp, rs_list);
416 
417 	/* not synced anymore */
418 	rfp->rf_flags &= ~RCS_RF_SYNCED;
419 
420 	return (0);
421 }
422 
423 
424 /*
425  * rcs_patch()
426  *
427  * Apply an RCS-format patch pointed to by <patch> to the file contents
428  * found in <data>.
429  * Returns 0 on success, or -1 on failure.
430  */
431 
432 BUF*
433 rcs_patch(const char *data, const char *patch)
434 {
435 	struct rcs_foo *dlines, *plines;
436 	struct rcs_line *lp;
437 	size_t len;
438 	int lineno;
439 	BUF *res;
440 
441 	len = strlen(data);
442 	res = cvs_buf_alloc(len, BUF_AUTOEXT);
443 	if (res == NULL)
444 		return (NULL);
445 
446 	dlines = rcs_splitlines(data);
447 	if (dlines == NULL) {
448 		cvs_buf_free(res);
449 		return (NULL);
450 	}
451 
452 	plines = rcs_splitlines(patch);
453 	if (plines == NULL) {
454 		cvs_buf_free(res);
455 		rcs_freefoo(dlines);
456 		return (NULL);
457 	}
458 
459 	if (rcs_patch_lines(dlines, plines) < 0) {
460 		cvs_buf_free(res);
461 		rcs_freefoo(plines);
462 		rcs_freefoo(dlines);
463 		return (NULL);
464 	}
465 
466 	lineno = 0;
467 	TAILQ_FOREACH(lp, &dlines->rl_lines, rl_list) {
468 		if (lineno != 0)
469 			cvs_buf_fappend(res, "%s\n", lp->rl_line);
470 		lineno++;
471 	}
472 
473 	rcs_freefoo(dlines);
474 	rcs_freefoo(plines);
475 	return (res);
476 }
477 
478 static int
479 rcs_patch_lines(struct rcs_foo *dlines, struct rcs_foo *plines)
480 {
481 	char op, *ep;
482 	struct rcs_line *lp, *dlp, *ndlp;
483 	int i, lineno, nbln;
484 
485 	dlp = TAILQ_FIRST(&(dlines->rl_lines));
486 	lp = TAILQ_FIRST(&(plines->rl_lines));
487 
488 	/* skip first bogus line */
489 	for (lp = TAILQ_NEXT(lp, rl_list); lp != NULL;
490 	    lp = TAILQ_NEXT(lp, rl_list)) {
491 		op = *(lp->rl_line);
492 		lineno = (int)strtol((lp->rl_line + 1), &ep, 10);
493 		if ((lineno > dlines->rl_nblines) || (lineno <= 0) ||
494 		    (*ep != ' ')) {
495 			cvs_log(LP_ERR,
496 			    "invalid line specification in RCS patch");
497 			return (NULL);
498 		}
499 		ep++;
500 		nbln = (int)strtol(ep, &ep, 10);
501 		if ((nbln <= 0) || (*ep != '\0')) {
502 			cvs_log(LP_ERR,
503 			    "invalid line number specification in RCS patch");
504 			return (NULL);
505 		}
506 
507 		/* find the appropriate line */
508 		for (;;) {
509 			if (dlp == NULL)
510 				break;
511 			if (dlp->rl_lineno == lineno)
512 				break;
513 			if (dlp->rl_lineno > lineno) {
514 				dlp = TAILQ_PREV(dlp, rcs_tqh, rl_list);
515 			} else if (dlp->rl_lineno < lineno) {
516 				ndlp = TAILQ_NEXT(dlp, rl_list);
517 				if (ndlp->rl_lineno > lineno)
518 					break;
519 				dlp = ndlp;
520 			}
521 		}
522 		if (dlp == NULL) {
523 			cvs_log(LP_ERR,
524 			    "can't find referenced line in RCS patch");
525 			return (NULL);
526 		}
527 
528 		if (op == 'd') {
529 			for (i = 0; (i < nbln) && (dlp != NULL); i++) {
530 				ndlp = TAILQ_NEXT(dlp, rl_list);
531 				TAILQ_REMOVE(&(dlines->rl_lines), dlp, rl_list);
532 				dlp = ndlp;
533 			}
534 		} else if (op == 'a') {
535 			for (i = 0; i < nbln; i++) {
536 				ndlp = lp;
537 				lp = TAILQ_NEXT(lp, rl_list);
538 				if (lp == NULL) {
539 					cvs_log(LP_ERR, "truncated RCS patch");
540 					return (-1);
541 				}
542 				TAILQ_REMOVE(&(plines->rl_lines), lp, rl_list);
543 				TAILQ_INSERT_AFTER(&(dlines->rl_lines), dlp,
544 				    lp, rl_list);
545 				dlp = lp;
546 
547 				/* we don't want lookup to block on those */
548 				lp->rl_lineno = lineno;
549 
550 				lp = ndlp;
551 			}
552 		} else {
553 			cvs_log(LP_ERR, "unknown RCS patch operation `%c'", op);
554 			return (-1);
555 		}
556 
557 		/* last line of the patch, done */
558 		if (lp->rl_lineno == plines->rl_nblines)
559 			break;
560 	}
561 
562 	/* once we're done patching, rebuild the line numbers */
563 	lineno = 0;
564 	TAILQ_FOREACH(lp, &(dlines->rl_lines), rl_list)
565 		lp->rl_lineno = lineno++;
566 	dlines->rl_nblines = lineno - 1;
567 
568 	return (0);
569 }
570 
571 
572 /*
573  * rcs_getrev()
574  *
575  * Get the whole contents of revision <rev> from the RCSFILE <rfp>.  The
576  * returned buffer is dynamically allocated and should be released using
577  * cvs_buf_free() once the caller is done using it.
578  */
579 
580 BUF*
581 rcs_getrev(RCSFILE *rfp, RCSNUM *rev)
582 {
583 	int res;
584 	size_t len;
585 	void *bp;
586 	RCSNUM *crev;
587 	BUF *rbuf;
588 	struct rcs_delta *rdp = NULL;
589 
590 	res = rcsnum_cmp(rfp->rf_head, rev, 0);
591 	if (res == 1) {
592 		cvs_log(LP_ERR, "sorry, can't travel in the future yet");
593 		return (NULL);
594 	} else {
595 		rdp = rcs_findrev(rfp, rfp->rf_head);
596 		if (rdp == NULL) {
597 			cvs_log(LP_ERR, "failed to get RCS HEAD revision");
598 			return (NULL);
599 		}
600 
601 		len = strlen(rdp->rd_text);
602 		rbuf = cvs_buf_alloc(len, BUF_AUTOEXT);
603 		if (rbuf == NULL)
604 			return (NULL);
605 		cvs_buf_append(rbuf, rdp->rd_text, len);
606 
607 		if (res != 0) {
608 			/* Apply patches backwards to get the right version.
609 			 * This will need some rework to support sub branches.
610 			 */
611 			crev = rcsnum_alloc();
612 			if (crev == NULL) {
613 				cvs_buf_free(rbuf);
614 				return (NULL);
615 			}
616 			rcsnum_cpy(rfp->rf_head, crev, 0);
617 			do {
618 				crev->rn_id[crev->rn_len - 1]--;
619 				rdp = rcs_findrev(rfp, crev);
620 				if (rdp == NULL) {
621 					rcsnum_free(crev);
622 					cvs_buf_free(rbuf);
623 					return (NULL);
624 				}
625 
626 				cvs_buf_putc(rbuf, '\0');
627 				bp = cvs_buf_release(rbuf);
628 				rbuf = rcs_patch((char *)bp, rdp->rd_text);
629 				if (rbuf == NULL)
630 					break;
631 			} while (rcsnum_cmp(crev, rev, 0) != 0);
632 
633 			rcsnum_free(crev);
634 		}
635 	}
636 
637 	return (rbuf);
638 }
639 
640 
641 /*
642  * rcs_gethead()
643  *
644  * Get the head revision for the RCS file <rf>.
645  */
646 BUF*
647 rcs_gethead(RCSFILE *rf)
648 {
649 	return rcs_getrev(rf, rf->rf_head);
650 }
651 
652 
653 /*
654  * rcs_getrevbydate()
655  *
656  * Get an RCS revision by a specific date.
657  */
658 
659 RCSNUM*
660 rcs_getrevbydate(RCSFILE *rfp, struct tm *date)
661 {
662 	return (NULL);
663 }
664 
665 
666 /*
667  * rcs_findrev()
668  *
669  * Find a specific revision's delta entry in the tree of the RCS file <rfp>.
670  * The revision number is given in <rev>.
671  * Returns a pointer to the delta on success, or NULL on failure.
672  */
673 
674 static struct rcs_delta*
675 rcs_findrev(RCSFILE *rfp, RCSNUM *rev)
676 {
677 	u_int cmplen;
678 	struct rcs_delta *rdp;
679 	struct rcs_dlist *hp;
680 	int found;
681 
682 	cmplen = 2;
683 	hp = &(rfp->rf_delta);
684 
685 	do {
686 		found = 0;
687 		TAILQ_FOREACH(rdp, hp, rd_list) {
688 			if (rcsnum_cmp(rdp->rd_num, rev, cmplen) == 0) {
689 				if (cmplen == rev->rn_len)
690 					return (rdp);
691 
692 				hp = &(rdp->rd_snodes);
693 				cmplen += 2;
694 				found = 1;
695 				break;
696 			}
697 		}
698 	} while (found && cmplen < rev->rn_len);
699 
700 	return (NULL);
701 }
702 
703 
704 /*
705  * rcs_parse()
706  *
707  * Parse the contents of file <path>, which are in the RCS format.
708  * Returns 0 on success, or -1 on failure.
709  */
710 
711 int
712 rcs_parse(RCSFILE *rfp)
713 {
714 	int ret;
715 	struct rcs_pdata *pdp;
716 
717 	if (rfp->rf_flags & RCS_RF_PARSED)
718 		return (0);
719 
720 	pdp = (struct rcs_pdata *)malloc(sizeof(*pdp));
721 	if (pdp == NULL) {
722 		cvs_log(LP_ERRNO, "failed to allocate RCS parser data");
723 		return (-1);
724 	}
725 	memset(pdp, 0, sizeof(*pdp));
726 
727 	pdp->rp_lines = 0;
728 	pdp->rp_pttype = RCS_TOK_ERR;
729 
730 	pdp->rp_file = fopen(rfp->rf_path, "r");
731 	if (pdp->rp_file == NULL) {
732 		cvs_log(LP_ERRNO, "failed to open RCS file `%s'", rfp->rf_path);
733 		rcs_freepdata(pdp);
734 		return (-1);
735 	}
736 
737 	pdp->rp_buf = (char *)malloc(RCS_BUFSIZE);
738 	if (pdp->rp_buf == NULL) {
739 		cvs_log(LP_ERRNO, "failed to allocate RCS parser buffer");
740 		rcs_freepdata(pdp);
741 		return (-1);
742 	}
743 	pdp->rp_blen = RCS_BUFSIZE;
744 	pdp->rp_bufend = pdp->rp_buf + pdp->rp_blen - 1;
745 
746 	/* ditch the strict lock */
747 	rfp->rf_flags &= ~RCS_RF_SLOCK;
748 	rfp->rf_pdata = pdp;
749 
750 	if (rcs_parse_admin(rfp) < 0) {
751 		rcs_freepdata(pdp);
752 		return (-1);
753 	}
754 
755 	for (;;) {
756 		ret = rcs_parse_delta(rfp);
757 		if (ret == 0)
758 			break;
759 		else if (ret == -1) {
760 			rcs_freepdata(pdp);
761 			return (-1);
762 		}
763 	}
764 
765 	ret = rcs_gettok(rfp);
766 	if (ret != RCS_TOK_DESC) {
767 		cvs_log(LP_ERR, "token `%s' found where RCS desc expected",
768 		    RCS_TOKSTR(rfp));
769 		rcs_freepdata(pdp);
770 		return (-1);
771 	}
772 
773 	ret = rcs_gettok(rfp);
774 	if (ret != RCS_TOK_STRING) {
775 		cvs_log(LP_ERR, "token `%s' found where RCS desc expected",
776 		    RCS_TOKSTR(rfp));
777 		rcs_freepdata(pdp);
778 		return (-1);
779 	}
780 
781 	rfp->rf_desc = strdup(RCS_TOKSTR(rfp));
782 	if (rfp->rf_desc == NULL) {
783 		cvs_log(LP_ERRNO, "failed to duplicate rcs token");
784 		rcs_freepdata(pdp);
785 		return (-1);
786 	}
787 
788 	for (;;) {
789 		ret = rcs_parse_deltatext(rfp);
790 		if (ret == 0)
791 			break;
792 		else if (ret == -1) {
793 			rcs_freepdata(pdp);
794 			return (-1);
795 		}
796 	}
797 
798 	cvs_log(LP_DEBUG, "RCS file `%s' parsed OK (%u lines)", rfp->rf_path,
799 	    pdp->rp_lines);
800 
801 	rcs_freepdata(pdp);
802 
803 	rfp->rf_pdata = NULL;
804 	rfp->rf_flags |= RCS_RF_PARSED|RCS_RF_SYNCED;
805 
806 	return (0);
807 }
808 
809 
810 /*
811  * rcs_parse_admin()
812  *
813  * Parse the administrative portion of an RCS file.
814  * Returns 0 on success, or -1 on failure.
815  */
816 
817 static int
818 rcs_parse_admin(RCSFILE *rfp)
819 {
820 	u_int i;
821 	int tok, ntok, hmask;
822 	struct rcs_key *rk;
823 
824 	/* hmask is a mask of the headers already encountered */
825 	hmask = 0;
826 	for (;;) {
827 		tok = rcs_gettok(rfp);
828 		if (tok == RCS_TOK_ERR) {
829 			cvs_log(LP_ERR, "parse error in RCS admin section");
830 			return (-1);
831 		} else if (tok == RCS_TOK_NUM) {
832 			/* assume this is the start of the first delta */
833 			rcs_pushtok(rfp, RCS_TOKSTR(rfp), tok);
834 			return (0);
835 		}
836 
837 		rk = NULL;
838 		for (i = 0; i < RCS_NKEYS; i++)
839 			if (rcs_keys[i].rk_id == tok)
840 				rk = &(rcs_keys[i]);
841 
842 		if (hmask & (1 << tok)) {
843 			cvs_log(LP_ERR, "duplicate RCS key");
844 			return (-1);
845 		}
846 		hmask |= (1 << tok);
847 
848 		switch (tok) {
849 		case RCS_TOK_HEAD:
850 		case RCS_TOK_BRANCH:
851 		case RCS_TOK_COMMENT:
852 		case RCS_TOK_EXPAND:
853 			ntok = rcs_gettok(rfp);
854 			if (ntok == RCS_TOK_SCOLON)
855 				break;
856 			if (ntok != rk->rk_val) {
857 				cvs_log(LP_ERR,
858 				    "invalid value type for RCS key `%s'",
859 				    rk->rk_str);
860 			}
861 
862 			if (tok == RCS_TOK_HEAD) {
863 				rcsnum_aton(RCS_TOKSTR(rfp), NULL,
864 				    rfp->rf_head);
865 			} else if (tok == RCS_TOK_BRANCH) {
866 				rcsnum_aton(RCS_TOKSTR(rfp), NULL,
867 				    rfp->rf_branch);
868 			} else if (tok == RCS_TOK_COMMENT) {
869 				rfp->rf_comment = strdup(RCS_TOKSTR(rfp));
870 				if (rfp->rf_comment == NULL) {
871 					cvs_log(LP_ERRNO,
872 					    "failed to duplicate rcs token");
873 					return (-1);
874 				}
875 			} else if (tok == RCS_TOK_EXPAND) {
876 				rfp->rf_expand = strdup(RCS_TOKSTR(rfp));
877 				if (rfp->rf_expand == NULL) {
878 					cvs_log(LP_ERRNO,
879 					    "failed to duplicate rcs token");
880 					return (-1);
881 				}
882 			}
883 
884 			/* now get the expected semi-colon */
885 			ntok = rcs_gettok(rfp);
886 			if (ntok != RCS_TOK_SCOLON) {
887 				cvs_log(LP_ERR,
888 				    "missing semi-colon after RCS `%s' key",
889 				    rk->rk_str);
890 				return (-1);
891 			}
892 			break;
893 		case RCS_TOK_ACCESS:
894 			rcs_parse_access(rfp);
895 			break;
896 		case RCS_TOK_SYMBOLS:
897 			rcs_parse_symbols(rfp);
898 			break;
899 		case RCS_TOK_LOCKS:
900 			rcs_parse_locks(rfp);
901 			break;
902 		default:
903 			cvs_log(LP_ERR,
904 			    "unexpected token `%s' in RCS admin section",
905 			    RCS_TOKSTR(rfp));
906 			return (-1);
907 		}
908 	}
909 
910 	return (0);
911 }
912 
913 
914 /*
915  * rcs_parse_delta()
916  *
917  * Parse an RCS delta section and allocate the structure to store that delta's
918  * information in the <rfp> delta list.
919  * Returns 1 if the section was parsed OK, 0 if it is the last delta, and
920  * -1 on error.
921  */
922 
923 static int
924 rcs_parse_delta(RCSFILE *rfp)
925 {
926 	int ret, tok, ntok, hmask;
927 	u_int i;
928 	char *tokstr;
929 	RCSNUM *datenum;
930 	struct rcs_delta *rdp;
931 	struct rcs_key *rk;
932 
933 	rdp = (struct rcs_delta *)malloc(sizeof(*rdp));
934 	if (rdp == NULL) {
935 		cvs_log(LP_ERRNO, "failed to allocate RCS delta structure");
936 		return (-1);
937 	}
938 	memset(rdp, 0, sizeof(*rdp));
939 
940 	rdp->rd_num = rcsnum_alloc();
941 	if (rdp->rd_num == NULL) {
942 		rcs_freedelta(rdp);
943 		return (-1);
944 	}
945 	rdp->rd_next = rcsnum_alloc();
946 	if (rdp->rd_next == NULL) {
947 		rcs_freedelta(rdp);
948 		return (-1);
949 	}
950 
951 	TAILQ_INIT(&(rdp->rd_branches));
952 
953 	tok = rcs_gettok(rfp);
954 	if (tok != RCS_TOK_NUM) {
955 		cvs_log(LP_ERR, "unexpected token `%s' at start of delta",
956 		    RCS_TOKSTR(rfp));
957 		rcs_freedelta(rdp);
958 		return (-1);
959 	}
960 	rcsnum_aton(RCS_TOKSTR(rfp), NULL, rdp->rd_num);
961 
962 	hmask = 0;
963 	ret = 0;
964 	tokstr = NULL;
965 
966 	for (;;) {
967 		tok = rcs_gettok(rfp);
968 		if (tok == RCS_TOK_ERR) {
969 			cvs_log(LP_ERR, "parse error in RCS delta section");
970 			rcs_freedelta(rdp);
971 			return (-1);
972 		} else if (tok == RCS_TOK_NUM || tok == RCS_TOK_DESC) {
973 			rcs_pushtok(rfp, RCS_TOKSTR(rfp), tok);
974 			ret = (tok == RCS_TOK_NUM ? 1 : 0);
975 			break;
976 		}
977 
978 		rk = NULL;
979 		for (i = 0; i < RCS_NKEYS; i++)
980 			if (rcs_keys[i].rk_id == tok)
981 				rk = &(rcs_keys[i]);
982 
983 		if (hmask & (1 << tok)) {
984 			cvs_log(LP_ERR, "duplicate RCS key");
985 			rcs_freedelta(rdp);
986 			return (-1);
987 		}
988 		hmask |= (1 << tok);
989 
990 		switch (tok) {
991 		case RCS_TOK_DATE:
992 		case RCS_TOK_AUTHOR:
993 		case RCS_TOK_STATE:
994 		case RCS_TOK_NEXT:
995 			ntok = rcs_gettok(rfp);
996 			if (ntok == RCS_TOK_SCOLON) {
997 				if (rk->rk_flags & RCS_VOPT)
998 					break;
999 				else {
1000 					cvs_log(LP_ERR, "missing mandatory "
1001 					    "value to RCS key `%s'",
1002 					    rk->rk_str);
1003 					rcs_freedelta(rdp);
1004 					return (-1);
1005 				}
1006 			}
1007 
1008 			if (ntok != rk->rk_val) {
1009 				cvs_log(LP_ERR,
1010 				    "invalid value type for RCS key `%s'",
1011 				    rk->rk_str);
1012 				rcs_freedelta(rdp);
1013 				return (-1);
1014 			}
1015 
1016 			if (tokstr != NULL)
1017 				free(tokstr);
1018 			tokstr = strdup(RCS_TOKSTR(rfp));
1019 			if (tokstr == NULL) {
1020 				cvs_log(LP_ERRNO,
1021 				    "failed to duplicate rcs token");
1022 				rcs_freedelta(rdp);
1023 				return (-1);
1024 			}
1025 
1026 			/* now get the expected semi-colon */
1027 			ntok = rcs_gettok(rfp);
1028 			if (ntok != RCS_TOK_SCOLON) {
1029 				cvs_log(LP_ERR,
1030 				    "missing semi-colon after RCS `%s' key",
1031 				    rk->rk_str);
1032 				rcs_freedelta(rdp);
1033 				return (-1);
1034 			}
1035 
1036 			if (tok == RCS_TOK_DATE) {
1037 				datenum = rcsnum_alloc();
1038 				if (datenum == NULL) {
1039 					rcs_freedelta(rdp);
1040 					return (-1);
1041 				}
1042 				rcsnum_aton(tokstr, NULL, datenum);
1043 				if (datenum->rn_len != 6) {
1044 					cvs_log(LP_ERR,
1045 					    "RCS date specification has %s "
1046 					    "fields",
1047 					    (datenum->rn_len > 6) ? "too many" :
1048 					    "missing");
1049 					rcs_freedelta(rdp);
1050 				}
1051 				rdp->rd_date.tm_year = datenum->rn_id[0];
1052 				if (rdp->rd_date.tm_year >= 1900)
1053 					rdp->rd_date.tm_year -= 1900;
1054 				rdp->rd_date.tm_mon = datenum->rn_id[1] - 1;
1055 				rdp->rd_date.tm_mday = datenum->rn_id[2];
1056 				rdp->rd_date.tm_hour = datenum->rn_id[3];
1057 				rdp->rd_date.tm_min = datenum->rn_id[4];
1058 				rdp->rd_date.tm_sec = datenum->rn_id[5];
1059 				rcsnum_free(datenum);
1060 			} else if (tok == RCS_TOK_AUTHOR) {
1061 				rdp->rd_author = tokstr;
1062 				tokstr = NULL;
1063 			} else if (tok == RCS_TOK_STATE) {
1064 				rdp->rd_state = tokstr;
1065 				tokstr = NULL;
1066 			} else if (tok == RCS_TOK_NEXT) {
1067 				rcsnum_aton(tokstr, NULL, rdp->rd_next);
1068 			}
1069 			break;
1070 		case RCS_TOK_BRANCHES:
1071 			rcs_parse_branches(rfp, rdp);
1072 			break;
1073 		default:
1074 			cvs_log(LP_ERR,
1075 			    "unexpected token `%s' in RCS delta",
1076 			    RCS_TOKSTR(rfp));
1077 			rcs_freedelta(rdp);
1078 			return (-1);
1079 		}
1080 	}
1081 
1082 	if (tokstr != NULL)
1083 		free(tokstr);
1084 
1085 	TAILQ_INSERT_TAIL(&(rfp->rf_delta), rdp, rd_list);
1086 
1087 	return (ret);
1088 }
1089 
1090 
1091 /*
1092  * rcs_parse_deltatext()
1093  *
1094  * Parse an RCS delta text section and fill in the log and text field of the
1095  * appropriate delta section.
1096  * Returns 1 if the section was parsed OK, 0 if it is the last delta, and
1097  * -1 on error.
1098  */
1099 
1100 static int
1101 rcs_parse_deltatext(RCSFILE *rfp)
1102 {
1103 	int tok;
1104 	RCSNUM *tnum;
1105 	struct rcs_delta *rdp;
1106 
1107 	tok = rcs_gettok(rfp);
1108 	if (tok == RCS_TOK_EOF)
1109 		return (0);
1110 
1111 	if (tok != RCS_TOK_NUM) {
1112 		cvs_log(LP_ERR,
1113 		    "unexpected token `%s' at start of RCS delta text",
1114 		    RCS_TOKSTR(rfp));
1115 		return (-1);
1116 	}
1117 
1118 	tnum = rcsnum_alloc();
1119 	if (tnum == NULL)
1120 		return (-1);
1121 	rcsnum_aton(RCS_TOKSTR(rfp), NULL, tnum);
1122 
1123 	TAILQ_FOREACH(rdp, &(rfp->rf_delta), rd_list) {
1124 		if (rcsnum_cmp(tnum, rdp->rd_num, 0) == 0)
1125 			break;
1126 	}
1127 	rcsnum_free(tnum);
1128 
1129 	if (rdp == NULL) {
1130 		cvs_log(LP_ERR, "RCS delta text `%s' has no matching delta",
1131 		    RCS_TOKSTR(rfp));
1132 		return (-1);
1133 	}
1134 
1135 	tok = rcs_gettok(rfp);
1136 	if (tok != RCS_TOK_LOG) {
1137 		cvs_log(LP_ERR, "unexpected token `%s' where RCS log expected",
1138 		    RCS_TOKSTR(rfp));
1139 		return (-1);
1140 	}
1141 
1142 	tok = rcs_gettok(rfp);
1143 	if (tok != RCS_TOK_STRING) {
1144 		cvs_log(LP_ERR, "unexpected token `%s' where RCS log expected",
1145 		    RCS_TOKSTR(rfp));
1146 		return (-1);
1147 	}
1148 	rdp->rd_log = strdup(RCS_TOKSTR(rfp));
1149 	if (rdp->rd_log == NULL) {
1150 		cvs_log(LP_ERRNO, "failed to copy RCS deltatext log");
1151 		return (-1);
1152 	}
1153 
1154 	tok = rcs_gettok(rfp);
1155 	if (tok != RCS_TOK_TEXT) {
1156 		cvs_log(LP_ERR, "unexpected token `%s' where RCS text expected",
1157 		    RCS_TOKSTR(rfp));
1158 		return (-1);
1159 	}
1160 
1161 	tok = rcs_gettok(rfp);
1162 	if (tok != RCS_TOK_STRING) {
1163 		cvs_log(LP_ERR, "unexpected token `%s' where RCS text expected",
1164 		    RCS_TOKSTR(rfp));
1165 		return (-1);
1166 	}
1167 
1168 	rdp->rd_text = strdup(RCS_TOKSTR(rfp));
1169 	if (rdp->rd_text == NULL) {
1170 		cvs_log(LP_ERRNO, "failed to copy RCS delta text");
1171 		return (-1);
1172 	}
1173 
1174 	return (1);
1175 }
1176 
1177 
1178 /*
1179  * rcs_parse_access()
1180  *
1181  * Parse the access list given as value to the `access' keyword.
1182  * Returns 0 on success, or -1 on failure.
1183  */
1184 
1185 static int
1186 rcs_parse_access(RCSFILE *rfp)
1187 {
1188 	int type;
1189 
1190 	while ((type = rcs_gettok(rfp)) != RCS_TOK_SCOLON) {
1191 		if (type != RCS_TOK_ID) {
1192 			cvs_log(LP_ERR, "unexpected token `%s' in access list",
1193 			    RCS_TOKSTR(rfp));
1194 			return (-1);
1195 		}
1196 	}
1197 
1198 	return (0);
1199 }
1200 
1201 
1202 /*
1203  * rcs_parse_symbols()
1204  *
1205  * Parse the symbol list given as value to the `symbols' keyword.
1206  * Returns 0 on success, or -1 on failure.
1207  */
1208 
1209 static int
1210 rcs_parse_symbols(RCSFILE *rfp)
1211 {
1212 	int type;
1213 	struct rcs_sym *symp;
1214 
1215 	for (;;) {
1216 		type = rcs_gettok(rfp);
1217 		if (type == RCS_TOK_SCOLON)
1218 			break;
1219 
1220 		if (type != RCS_TOK_STRING) {
1221 			cvs_log(LP_ERR, "unexpected token `%s' in symbol list",
1222 			    RCS_TOKSTR(rfp));
1223 			return (-1);
1224 		}
1225 
1226 		symp = (struct rcs_sym *)malloc(sizeof(*symp));
1227 		if (symp == NULL) {
1228 			cvs_log(LP_ERRNO, "failed to allocate RCS symbol");
1229 			return (-1);
1230 		}
1231 		symp->rs_name = strdup(RCS_TOKSTR(rfp));
1232 		if (symp->rs_name == NULL) {
1233 			cvs_log(LP_ERRNO, "failed to duplicate rcs token");
1234 			free(symp);
1235 			return (-1);
1236 		}
1237 
1238 		symp->rs_num = rcsnum_alloc();
1239 		if (symp->rs_num == NULL) {
1240 			cvs_log(LP_ERRNO, "failed to allocate rcsnum info");
1241 			free(symp);
1242 			return (-1);
1243 		}
1244 
1245 		type = rcs_gettok(rfp);
1246 		if (type != RCS_TOK_COLON) {
1247 			cvs_log(LP_ERR, "unexpected token `%s' in symbol list",
1248 			    RCS_TOKSTR(rfp));
1249 			rcsnum_free(symp->rs_num);
1250 			free(symp->rs_name);
1251 			free(symp);
1252 			return (-1);
1253 		}
1254 
1255 		type = rcs_gettok(rfp);
1256 		if (type != RCS_TOK_NUM) {
1257 			cvs_log(LP_ERR, "unexpected token `%s' in symbol list",
1258 			    RCS_TOKSTR(rfp));
1259 			rcsnum_free(symp->rs_num);
1260 			free(symp->rs_name);
1261 			free(symp);
1262 			return (-1);
1263 		}
1264 
1265 		if (rcsnum_aton(RCS_TOKSTR(rfp), NULL, symp->rs_num) < 0) {
1266 			cvs_log(LP_ERR, "failed to parse RCS NUM `%s'",
1267 			    RCS_TOKSTR(rfp));
1268 			rcsnum_free(symp->rs_num);
1269 			free(symp->rs_name);
1270 			free(symp);
1271 			return (-1);
1272 		}
1273 
1274 		TAILQ_INSERT_HEAD(&(rfp->rf_symbols), symp, rs_list);
1275 	}
1276 
1277 	return (0);
1278 }
1279 
1280 
1281 /*
1282  * rcs_parse_locks()
1283  *
1284  * Parse the lock list given as value to the `locks' keyword.
1285  * Returns 0 on success, or -1 on failure.
1286  */
1287 
1288 static int
1289 rcs_parse_locks(RCSFILE *rfp)
1290 {
1291 	int type;
1292 	struct rcs_lock *lkp;
1293 
1294 	for (;;) {
1295 		type = rcs_gettok(rfp);
1296 		if (type == RCS_TOK_SCOLON)
1297 			break;
1298 
1299 		if (type != RCS_TOK_ID) {
1300 			cvs_log(LP_ERR, "unexpected token `%s' in lock list",
1301 			    RCS_TOKSTR(rfp));
1302 			return (-1);
1303 		}
1304 
1305 		lkp = (struct rcs_lock *)malloc(sizeof(*lkp));
1306 		if (lkp == NULL) {
1307 			cvs_log(LP_ERRNO, "failed to allocate RCS lock");
1308 			return (-1);
1309 		}
1310 		lkp->rl_num = rcsnum_alloc();
1311 		if (lkp->rl_num == NULL) {
1312 			free(lkp);
1313 			return (-1);
1314 		}
1315 
1316 		type = rcs_gettok(rfp);
1317 		if (type != RCS_TOK_COLON) {
1318 			cvs_log(LP_ERR, "unexpected token `%s' in symbol list",
1319 			    RCS_TOKSTR(rfp));
1320 			free(lkp);
1321 			return (-1);
1322 		}
1323 
1324 		type = rcs_gettok(rfp);
1325 		if (type != RCS_TOK_NUM) {
1326 			cvs_log(LP_ERR, "unexpected token `%s' in symbol list",
1327 			    RCS_TOKSTR(rfp));
1328 			free(lkp);
1329 			return (-1);
1330 		}
1331 
1332 		if (rcsnum_aton(RCS_TOKSTR(rfp), NULL, lkp->rl_num) < 0) {
1333 			cvs_log(LP_ERR, "failed to parse RCS NUM `%s'",
1334 			    RCS_TOKSTR(rfp));
1335 			free(lkp);
1336 			return (-1);
1337 		}
1338 
1339 		TAILQ_INSERT_HEAD(&(rfp->rf_locks), lkp, rl_list);
1340 	}
1341 
1342 	/* check if we have a `strict' */
1343 	type = rcs_gettok(rfp);
1344 	if (type != RCS_TOK_STRICT) {
1345 		rcs_pushtok(rfp, RCS_TOKSTR(rfp), type);
1346 	} else {
1347 		rfp->rf_flags |= RCS_RF_SLOCK;
1348 
1349 		type = rcs_gettok(rfp);
1350 		if (type != RCS_TOK_SCOLON) {
1351 			cvs_log(LP_ERR,
1352 			    "missing semi-colon after `strict' keyword");
1353 			return (-1);
1354 		}
1355 	}
1356 
1357 	return (0);
1358 }
1359 
1360 /*
1361  * rcs_parse_branches()
1362  *
1363  * Parse the list of branches following a `branches' keyword in a delta.
1364  * Returns 0 on success, or -1 on failure.
1365  */
1366 
1367 static int
1368 rcs_parse_branches(RCSFILE *rfp, struct rcs_delta *rdp)
1369 {
1370 	int type;
1371 	struct rcs_branch *brp;
1372 
1373 	for (;;) {
1374 		type = rcs_gettok(rfp);
1375 		if (type == RCS_TOK_SCOLON)
1376 			break;
1377 
1378 		if (type != RCS_TOK_NUM) {
1379 			cvs_log(LP_ERR,
1380 			    "unexpected token `%s' in list of branches",
1381 			    RCS_TOKSTR(rfp));
1382 			return (-1);
1383 		}
1384 
1385 		brp = (struct rcs_branch *)malloc(sizeof(*brp));
1386 		if (brp == NULL) {
1387 			cvs_log(LP_ERRNO, "failed to allocate RCS branch");
1388 			return (-1);
1389 		}
1390 		brp->rb_num = rcsnum_alloc();
1391 		if (brp->rb_num == NULL) {
1392 			free(brp);
1393 			return (-1);
1394 		}
1395 
1396 		rcsnum_aton(RCS_TOKSTR(rfp), NULL, brp->rb_num);
1397 
1398 		TAILQ_INSERT_TAIL(&(rdp->rd_branches), brp, rb_list);
1399 	}
1400 
1401 	return (0);
1402 }
1403 
1404 
1405 /*
1406  * rcs_freedelta()
1407  *
1408  * Free the contents of a delta structure.
1409  */
1410 
1411 static void
1412 rcs_freedelta(struct rcs_delta *rdp)
1413 {
1414 	struct rcs_branch *rb;
1415 	struct rcs_delta *crdp;
1416 
1417 	if (rdp->rd_num != NULL)
1418 		rcsnum_free(rdp->rd_num);
1419 	if (rdp->rd_next != NULL)
1420 		rcsnum_free(rdp->rd_next);
1421 
1422 	if (rdp->rd_author != NULL)
1423 		free(rdp->rd_author);
1424 	if (rdp->rd_state != NULL)
1425 		free(rdp->rd_state);
1426 	if (rdp->rd_log != NULL)
1427 		free(rdp->rd_log);
1428 	if (rdp->rd_text != NULL)
1429 		free(rdp->rd_text);
1430 
1431 	while ((rb = TAILQ_FIRST(&(rdp->rd_branches))) != NULL) {
1432 		TAILQ_REMOVE(&(rdp->rd_branches), rb, rb_list);
1433 		rcsnum_free(rb->rb_num);
1434 		free(rb);
1435 	}
1436 
1437 	while ((crdp = TAILQ_FIRST(&(rdp->rd_snodes))) != NULL) {
1438 		TAILQ_REMOVE(&(rdp->rd_snodes), crdp, rd_list);
1439 		rcs_freedelta(crdp);
1440 	}
1441 
1442 	free(rdp);
1443 }
1444 
1445 
1446 /*
1447  * rcs_freepdata()
1448  *
1449  * Free the contents of the parser data structure.
1450  */
1451 
1452 static void
1453 rcs_freepdata(struct rcs_pdata *pd)
1454 {
1455 	if (pd->rp_file != NULL)
1456 		(void)fclose(pd->rp_file);
1457 	if (pd->rp_buf != NULL)
1458 		free(pd->rp_buf);
1459 	free(pd);
1460 }
1461 
1462 
1463 /*
1464  * rcs_gettok()
1465  *
1466  * Get the next RCS token from the string <str>.
1467  */
1468 
1469 static int
1470 rcs_gettok(RCSFILE *rfp)
1471 {
1472 	u_int i;
1473 	int ch, last, type;
1474 	size_t len;
1475 	char *bp;
1476 	struct rcs_pdata *pdp = (struct rcs_pdata *)rfp->rf_pdata;
1477 
1478 	type = RCS_TOK_ERR;
1479 	bp = pdp->rp_buf;
1480 	*bp = '\0';
1481 
1482 	if (pdp->rp_pttype != RCS_TOK_ERR) {
1483 		type = pdp->rp_pttype;
1484 		strlcpy(pdp->rp_buf, pdp->rp_ptok, pdp->rp_blen);
1485 		pdp->rp_pttype = RCS_TOK_ERR;
1486 		return (type);
1487 	}
1488 
1489 	/* skip leading whitespace */
1490 	/* XXX we must skip backspace too for compatibility, should we? */
1491 	do {
1492 		ch = getc(pdp->rp_file);
1493 		if (ch == '\n')
1494 			pdp->rp_lines++;
1495 	} while (isspace(ch));
1496 
1497 	if (ch == EOF) {
1498 		type = RCS_TOK_EOF;
1499 	} else if (ch == ';') {
1500 		type = RCS_TOK_SCOLON;
1501 	} else if (ch == ':') {
1502 		type = RCS_TOK_COLON;
1503 	} else if (isalpha(ch)) {
1504 		type = RCS_TOK_STRING;
1505 		*(bp++) = ch;
1506 		for (;;) {
1507 			ch = getc(pdp->rp_file);
1508 			if (!isalnum(ch) && ch != '_' && ch != '-') {
1509 				ungetc(ch, pdp->rp_file);
1510 				break;
1511 			}
1512 			*(bp++) = ch;
1513 			if (bp == pdp->rp_bufend - 1) {
1514 				len = bp - pdp->rp_buf;
1515 				if (rcs_growbuf(rfp) < 0) {
1516 					type = RCS_TOK_ERR;
1517 					break;
1518 				}
1519 				bp = pdp->rp_buf + len;
1520 			}
1521 		}
1522 		*bp = '\0';
1523 
1524 		if (type != RCS_TOK_ERR) {
1525 			for (i = 0; i < RCS_NKEYS; i++) {
1526 				if (strcmp(rcs_keys[i].rk_str,
1527 				    pdp->rp_buf) == 0) {
1528 					type = rcs_keys[i].rk_id;
1529 					break;
1530 				}
1531 			}
1532 		}
1533 	} else if (ch == '@') {
1534 		/* we have a string */
1535 		type = RCS_TOK_STRING;
1536 		for (;;) {
1537 			ch = getc(pdp->rp_file);
1538 			if (ch == '@') {
1539 				ch = getc(pdp->rp_file);
1540 				if (ch != '@') {
1541 					ungetc(ch, pdp->rp_file);
1542 					break;
1543 				}
1544 			} else if (ch == '\n')
1545 				pdp->rp_lines++;
1546 
1547 			*(bp++) = ch;
1548 			if (bp == pdp->rp_bufend - 1) {
1549 				len = bp - pdp->rp_buf;
1550 				if (rcs_growbuf(rfp) < 0) {
1551 					type = RCS_TOK_ERR;
1552 					break;
1553 				}
1554 				bp = pdp->rp_buf + len;
1555 			}
1556 		}
1557 
1558 		*bp = '\0';
1559 	} else if (isdigit(ch)) {
1560 		*(bp++) = ch;
1561 		last = ch;
1562 		type = RCS_TOK_NUM;
1563 
1564 		for (;;) {
1565 			ch = getc(pdp->rp_file);
1566 			if (bp == pdp->rp_bufend)
1567 				break;
1568 			if (!isdigit(ch) && ch != '.') {
1569 				ungetc(ch, pdp->rp_file);
1570 				break;
1571 			}
1572 
1573 			if (last == '.' && ch == '.') {
1574 				type = RCS_TOK_ERR;
1575 				break;
1576 			}
1577 			last = ch;
1578 			*(bp++) = ch;
1579 		}
1580 		*bp = '\0';
1581 	}
1582 
1583 	return (type);
1584 }
1585 
1586 
1587 /*
1588  * rcs_pushtok()
1589  *
1590  * Push a token back in the parser's token buffer.
1591  */
1592 
1593 static int
1594 rcs_pushtok(RCSFILE *rfp, const char *tok, int type)
1595 {
1596 	struct rcs_pdata *pdp = (struct rcs_pdata *)rfp->rf_pdata;
1597 
1598 	if (pdp->rp_pttype != RCS_TOK_ERR)
1599 		return (-1);
1600 
1601 	pdp->rp_pttype = type;
1602 	strlcpy(pdp->rp_ptok, tok, sizeof(pdp->rp_ptok));
1603 	return (0);
1604 }
1605 
1606 
1607 /*
1608  * rcs_stresc()
1609  *
1610  * Performs either escaping or unescaping of the string stored in <str>.
1611  * The operation is to escape special RCS characters if the <esc> argument
1612  * is 1, or unescape otherwise.  The result is stored in the <buf> destination
1613  * buffer, and <blen> must originally point to the size of <buf>.
1614  * Returns the number of bytes which have been read from the source <str> and
1615  * operated on.  The <blen> parameter will contain the number of bytes
1616  * actually copied in <buf>.
1617  */
1618 
1619 size_t
1620 rcs_stresc(int esc, const char *str, char *buf, size_t *blen)
1621 {
1622 	size_t rlen;
1623 	const char *sp;
1624 	char *bp, *bep;
1625 
1626 	rlen = 0;
1627 	bp = buf;
1628 	bep = buf + *blen - 1;
1629 
1630 	for (sp = str; (*sp != '\0') && (bp <= (bep - 1)); sp++) {
1631 		if (*sp == '@') {
1632 			if (esc) {
1633 				if (bp > (bep - 2))
1634 					break;
1635 				*(bp++) = '@';
1636 			} else {
1637 				sp++;
1638 				if (*sp != '@') {
1639 					cvs_log(LP_WARN,
1640 					    "unknown escape character `%c' in "
1641 					    "RCS file", *sp);
1642 					if (*sp == '\0')
1643 						break;
1644 				}
1645 			}
1646 		}
1647 
1648 		*(bp++) = *sp;
1649 	}
1650 
1651 	*bp = '\0';
1652 	*blen = (bp - buf);
1653 	return (sp - str);
1654 }
1655 
1656 
1657 /*
1658  * rcs_splitlines()
1659  *
1660  * Split the contents of a file into a list of lines.
1661  */
1662 
1663 static struct rcs_foo*
1664 rcs_splitlines(const char *fcont)
1665 {
1666 	char *dcp;
1667 	struct rcs_foo *foo;
1668 	struct rcs_line *lp;
1669 
1670 	foo = (struct rcs_foo *)malloc(sizeof(*foo));
1671 	if (foo == NULL) {
1672 		cvs_log(LP_ERR, "failed to allocate line structure");
1673 		return (NULL);
1674 	}
1675 	TAILQ_INIT(&(foo->rl_lines));
1676 	foo->rl_nblines = 0;
1677 	foo->rl_data = strdup(fcont);
1678 	if (foo->rl_data == NULL) {
1679 		cvs_log(LP_ERRNO, "failed to copy file contents");
1680 		free(foo);
1681 		return (NULL);
1682 	}
1683 
1684 	/*
1685 	 * Add a first bogus line with line number 0.  This is used so we
1686 	 * can position the line pointer before 1 when changing the first line
1687 	 * in rcs_patch().
1688 	 */
1689 	lp = (struct rcs_line *)malloc(sizeof(*lp));
1690 	if (lp == NULL)
1691 		return (NULL);
1692 
1693 	lp->rl_line = NULL;
1694 	lp->rl_lineno = 0;
1695 	TAILQ_INSERT_TAIL(&(foo->rl_lines), lp, rl_list);
1696 
1697 
1698 	for (dcp = foo->rl_data; *dcp != '\0';) {
1699 		lp = (struct rcs_line *)malloc(sizeof(*lp));
1700 		if (lp == NULL) {
1701 			cvs_log(LP_ERR, "failed to allocate line entry");
1702 			return (NULL);
1703 		}
1704 
1705 		lp->rl_line = dcp;
1706 		lp->rl_lineno = ++(foo->rl_nblines);
1707 		TAILQ_INSERT_TAIL(&(foo->rl_lines), lp, rl_list);
1708 
1709 		dcp = strchr(dcp, '\n');
1710 		if (dcp == NULL) {
1711 			break;
1712 		}
1713 		*(dcp++) = '\0';
1714 	}
1715 
1716 	return (foo);
1717 }
1718 
1719 static void
1720 rcs_freefoo(struct rcs_foo *fp)
1721 {
1722 	struct rcs_line *lp;
1723 
1724 	while ((lp = TAILQ_FIRST(&fp->rl_lines)) != NULL) {
1725 		TAILQ_REMOVE(&fp->rl_lines, lp, rl_list);
1726 		free(lp);
1727 	}
1728 	free(fp->rl_data);
1729 	free(fp);
1730 }
1731 
1732 /*
1733  * rcs_growbuf()
1734  *
1735  * Attempt to grow the internal parse buffer for the RCS file <rf> by
1736  * RCS_BUFEXTSIZE.
1737  * In case of failure, the original buffer is left unmodified.
1738  * Returns 0 on success, or -1 on failure.
1739  */
1740 
1741 static int
1742 rcs_growbuf(RCSFILE *rf)
1743 {
1744 	void *tmp;
1745 	struct rcs_pdata *pdp = (struct rcs_pdata *)rf->rf_pdata;
1746 
1747 	tmp = realloc(pdp->rp_buf, pdp->rp_blen + RCS_BUFEXTSIZE);
1748 	if (tmp == NULL) {
1749 		cvs_log(LP_ERRNO, "failed to grow RCS parse buffer");
1750 		return (-1);
1751 	}
1752 
1753 	pdp->rp_buf = (char *)tmp;
1754 	pdp->rp_blen += RCS_BUFEXTSIZE;
1755 	pdp->rp_bufend = pdp->rp_buf + pdp->rp_blen - 1;
1756 
1757 	return (0);
1758 }
1759