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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/rcs/rcsnum.c	Lines:	0	122	0.0 %
Date:	2017-11-13	Branches:	0	86	0.0 %


/*	$OpenBSD: rcsnum.c,v 1.20 2017/08/29 16:47:33 otto Exp $	*/
/*
 * Copyright (c) 2004 Jean-Francois Brousseau <jfb@openbsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <ctype.h>
#include <err.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "rcs.h"
#include "xmalloc.h"

#define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))

static void	 rcsnum_setsize(RCSNUM *, u_int);
static char	*rcsnum_itoa(u_int16_t, char *, size_t);

int rcsnum_flags;

/*
 * rcsnum_alloc()
 *
 * Allocate an RCS number structure and return a pointer to it.
 */
RCSNUM *
rcsnum_alloc(void)
{
	RCSNUM *rnp;

	rnp = xmalloc(sizeof(*rnp));
	rnp->rn_len = 0;
	rnp->rn_id = NULL;

	return (rnp);
}

/*
 * rcsnum_addmagic()
 *
 * Adds a magic branch number to an RCS number.
 * Returns 0 on success, or -1 on failure.
 */
int
rcsnum_addmagic(RCSNUM *rn)
{
	if (!rn->rn_len || rn->rn_len > RCSNUM_MAXLEN - 1)
		return -1;
	rcsnum_setsize(rn, rn->rn_len + 1);
	rn->rn_id[rn->rn_len - 1] = rn->rn_id[rn->rn_len - 2];
	rn->rn_id[rn->rn_len - 2] = 0;

	return 0;
}

/*
 * rcsnum_parse()
 *
 * Parse a string specifying an RCS number and return the corresponding RCSNUM.
 */
RCSNUM *
rcsnum_parse(const char *str)
{
	const char *ep;
	RCSNUM *num;

	num = rcsnum_alloc();
	if (rcsnum_aton(str, &ep, num) < 0 || *ep != '\0') {
		rcsnum_free(num);
		num = NULL;
		if (*ep != '\0')
			rcs_errno = RCS_ERR_BADNUM;
	}

	return (num);
}

/*
 * rcsnum_free()
 *
 * Free an RCSNUM structure previously allocated with rcsnum_alloc().
 */
void
rcsnum_free(RCSNUM *rn)
{
	if (rn == NULL)
		return;
	free(rn->rn_id);
	free(rn);
}

/*
 * rcsnum_tostr()
 *
 * Format the RCS number <nump> into a human-readable dot-separated
 * representation and store the resulting string in <buf>, which is of size
 * <blen>.
 * Returns a pointer to the start of <buf>.  On failure <buf> is set to
 * an empty string.
 */
char *
rcsnum_tostr(const RCSNUM *nump, char *buf, size_t blen)
{
	u_int i;
	char tmp[8];

	if (nump == NULL || nump->rn_len == 0) {
		buf[0] = '\0';
		return (buf);
	}

	if (strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen) >= blen)
		errx(1, "rcsnum_tostr: string truncated");
	for (i = 1; i < nump->rn_len; i++) {
		const char *str;

		str = rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp));
		if (strlcat(buf, ".", blen) >= blen ||
		    strlcat(buf, str, blen) >= blen)
			errx(1, "rcsnum_tostr: string truncated");
	}

	return (buf);
}

static char *
rcsnum_itoa(u_int16_t num, char *buf, size_t len)
{
	u_int16_t i;
	char *p;

	if (num == 0)
		return "0";

	p = buf + len - 1;
	i = num;
	bzero(buf, len);
	while (i) {
		*--p = '0' + (i % 10);
		i  /= 10;
	}
	return (p);
}

/*
 * rcsnum_cpy()
 *
 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
 * numbers deep.  If <depth> is 0, there is no depth limit.
 */
void
rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
{
	u_int len;

	len = nsrc->rn_len;
	if (depth != 0 && len > depth)
		len = depth;

	rcsnum_setsize(ndst, len);
	/* Overflow checked in rcsnum_setsize(). */
	(void)memcpy(ndst->rn_id, nsrc->rn_id,
	    len * sizeof(*(nsrc->rn_id)));
}

/*
 * rcsnum_cmp()
 *
 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
 * The <depth> argument specifies how many numbers deep should be checked for
 * the result.  A value of 0 means that the depth will be the maximum of the
 * two numbers, so that a longer number is considered greater than a shorter
 * number if they are equal up to the minimum length.
 */
int
rcsnum_cmp(const RCSNUM *n1, const RCSNUM *n2, u_int depth)
{
	int res;
	u_int i;
	size_t slen;

	slen = MINIMUM(n1->rn_len, n2->rn_len);
	if (depth != 0 && slen > depth)
		slen = depth;

	for (i = 0; i < slen; i++) {
		res = n1->rn_id[i] - n2->rn_id[i];
		if (res < 0)
			return (1);
		else if (res > 0)
			return (-1);
	}

	/* If an explicit depth was specified, and we've
	 * already checked up to depth, consider the
	 * revision numbers equal. */
	if (depth != 0 && slen == depth)
		return (0);
	else if (n1->rn_len > n2->rn_len)
		return (-1);
	else if (n2->rn_len > n1->rn_len)
		return (1);

	return (0);
}

/*
 * rcsnum_aton()
 *
 * Translate the string <str> containing a sequence of digits and periods into
 * its binary representation, which is stored in <nump>.  The address of the
 * first byte not part of the number is stored in <ep> on return, if it is not
 * NULL.
 * Returns 0 on success, or -1 on failure.
 */
int
rcsnum_aton(const char *str, const char **ep, RCSNUM *nump)
{
	u_int32_t val;
	const char *sp;
	char *s;

	if (nump->rn_id == NULL)
		nump->rn_id = xmalloc(sizeof(*(nump->rn_id)));

	nump->rn_len = 0;
	nump->rn_id[0] = 0;

	for (sp = str;; sp++) {
		if (!isdigit((unsigned char)*sp) && (*sp != '.'))
			break;

		if (*sp == '.') {
			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
				rcs_errno = RCS_ERR_BADNUM;
				goto rcsnum_aton_failed;
			}

			nump->rn_len++;
			nump->rn_id = xreallocarray(nump->rn_id,
			    nump->rn_len + 1, sizeof(*(nump->rn_id)));
			nump->rn_id[nump->rn_len] = 0;
			continue;
		}

		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - '0');
		if (val > RCSNUM_MAXNUM)
			errx(1, "RCSNUM overflow!");

		nump->rn_id[nump->rn_len] = val;
	}

	if (ep != NULL)
		*ep = sp;

	/*
	 * Handle "magic" RCS branch numbers.
	 *
	 * What are they?
	 *
	 * Magic branch numbers have an extra .0. at the second farmost
	 * rightside of the branch number, so instead of having an odd
	 * number of dot-separated decimals, it will have an even number.
	 *
	 * Now, according to all the documentation I've found on the net
	 * about this, cvs does this for "efficiency reasons", I'd like
	 * to hear one.
	 *
	 * We just make sure we remove the .0. from in the branch number.
	 *
	 * XXX - for compatibility reasons with GNU cvs we _need_
	 * to skip this part for the 'log' command, apparently it does
	 * show the magic branches for an unknown and probably
	 * completely insane and not understandable reason in that output.
	 *
	 */
	if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0
	    && !(rcsnum_flags & RCSNUM_NO_MAGIC)) {
		/*
		 * Look for ".0.x" at the end of the branch number.
		 */
		if ((s = strrchr(str, '.')) != NULL) {
			s--;
			while (*s != '.')
				s--;

			/*
			 * If we have a "magic" branch, adjust it
			 * so the .0. is removed.
			 */
			if (!strncmp(s, RCS_MAGIC_BRANCH,
			    strlen(RCS_MAGIC_BRANCH))) {
				nump->rn_id[nump->rn_len - 1] =
				    nump->rn_id[nump->rn_len];
				nump->rn_len--;
			}
		}
	}

	/* We can't have a single-digit rcs number. */
	if (nump->rn_len == 0) {
		nump->rn_len++;
		nump->rn_id = xreallocarray(nump->rn_id,
		    nump->rn_len + 1, sizeof(*(nump->rn_id)));
		nump->rn_id[nump->rn_len] = 0;
	}

	nump->rn_len++;
	return (nump->rn_len);

rcsnum_aton_failed:
	nump->rn_len = 0;
	free(nump->rn_id);
	nump->rn_id = NULL;
	return (-1);
}

/*
 * rcsnum_inc()
 *
 * Increment the revision number specified in <num>.
 * Returns a pointer to the <num> on success, or NULL on failure.
 */
RCSNUM *
rcsnum_inc(RCSNUM *num)
{
	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
		return (NULL);
	num->rn_id[num->rn_len - 1]++;
	return (num);
}

/*
 * rcsnum_revtobr()
 *
 * Retrieve the branch number associated with the revision number <num>.
 * If <num> is a branch revision, the returned value will be the same
 * number as the argument.
 */
RCSNUM *
rcsnum_revtobr(const RCSNUM *num)
{
	RCSNUM *brnum;

	if (num->rn_len < 2)
		return (NULL);

	brnum = rcsnum_alloc();
	rcsnum_cpy(num, brnum, 0);

	if (!RCSNUM_ISBRANCH(brnum))
		brnum->rn_len--;

	return (brnum);
}

/*
 * rcsnum_brtorev()
 *
 * Retrieve the initial revision number associated with the branch number <num>.
 * If <num> is a revision number, an error will be returned.
 */
RCSNUM *
rcsnum_brtorev(const RCSNUM *brnum)
{
	RCSNUM *num;

	if (!RCSNUM_ISBRANCH(brnum)) {
		return (NULL);
	}

	num = rcsnum_alloc();
	rcsnum_setsize(num, brnum->rn_len + 1);
	rcsnum_cpy(brnum, num, brnum->rn_len);
	num->rn_id[num->rn_len++] = 1;

	return (num);
}

static void
rcsnum_setsize(RCSNUM *num, u_int len)
{
	num->rn_id = xreallocarray(num->rn_id, len, sizeof(*(num->rn_id)));
	num->rn_len = len;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: rcsnum.c,v 1.20 2017/08/29 16:47:33 otto 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 <ctype.h>
28			#include <err.h>
29			#include <limits.h>
30			#include <stdlib.h>
31			#include <string.h>
32			#include <time.h>
33
34			#include "rcs.h"
35			#include "xmalloc.h"
36
37			#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
38
39			static void rcsnum_setsize(RCSNUM *, u_int);
40			static char rcsnum_itoa(u_int16_t, char , size_t);
41
42			int rcsnum_flags;
43
44			/*
45			* rcsnum_alloc()
46			*
47			* Allocate an RCS number structure and return a pointer to it.
48			*/
49			RCSNUM *
50			rcsnum_alloc(void)
51			{
52			RCSNUM *rnp;
53
54			rnp = xmalloc(sizeof(*rnp));
55			rnp->rn_len = 0;
56			rnp->rn_id = NULL;
57
58			return (rnp);
59			}
60
61			/*
62			* rcsnum_addmagic()
63			*
64			* Adds a magic branch number to an RCS number.
65			* Returns 0 on success, or -1 on failure.
66			*/
67			int
68			rcsnum_addmagic(RCSNUM *rn)
69			{
70			if (!rn->rn_len \|\| rn->rn_len > RCSNUM_MAXLEN - 1)
71			return -1;
72			rcsnum_setsize(rn, rn->rn_len + 1);
73			rn->rn_id[rn->rn_len - 1] = rn->rn_id[rn->rn_len - 2];
74			rn->rn_id[rn->rn_len - 2] = 0;
75
76			return 0;
77			}
78
79			/*
80			* rcsnum_parse()
81			*
82			* Parse a string specifying an RCS number and return the corresponding RCSNUM.
83			*/
84			RCSNUM *
85			rcsnum_parse(const char *str)
86			{
87			const char *ep;
88			RCSNUM *num;
89
90			num = rcsnum_alloc();
91			if (rcsnum_aton(str, &ep, num) < 0 \|\| *ep != '\0') {
92			rcsnum_free(num);
93			num = NULL;
94			if (*ep != '\0')
95			rcs_errno = RCS_ERR_BADNUM;
96			}
97
98			return (num);
99			}
100
101			/*
102			* rcsnum_free()
103			*
104			* Free an RCSNUM structure previously allocated with rcsnum_alloc().
105			*/
106			void
107			rcsnum_free(RCSNUM *rn)
108			{
109			if (rn == NULL)
110			return;
111			free(rn->rn_id);
112			free(rn);
113			}
114
115			/*
116			* rcsnum_tostr()
117			*
118			* Format the RCS number <nump> into a human-readable dot-separated
119			* representation and store the resulting string in <buf>, which is of size
120			* <blen>.
121			* Returns a pointer to the start of <buf>. On failure <buf> is set to
122			* an empty string.
123			*/
124			char *
125			rcsnum_tostr(const RCSNUM nump, char buf, size_t blen)
126			{
127			u_int i;
128			char tmp[8];
129
130			if (nump == NULL \|\| nump->rn_len == 0) {
131			buf[0] = '\0';
132			return (buf);
133			}
134
135			if (strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen) >= blen)
136			errx(1, "rcsnum_tostr: string truncated");
137			for (i = 1; i < nump->rn_len; i++) {
138			const char *str;
139
140			str = rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp));
141			if (strlcat(buf, ".", blen) >= blen \|\|
142			strlcat(buf, str, blen) >= blen)
143			errx(1, "rcsnum_tostr: string truncated");
144			}
145
146			return (buf);
147			}
148
149			static char *
150			rcsnum_itoa(u_int16_t num, char *buf, size_t len)
151			{
152			u_int16_t i;
153			char *p;
154
155			if (num == 0)
156			return "0";
157
158			p = buf + len - 1;
159			i = num;
160			bzero(buf, len);
161			while (i) {
162			*--p = '0' + (i % 10);
163			i /= 10;
164			}
165			return (p);
166			}
167
168			/*
169			* rcsnum_cpy()
170			*
171			* Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
172			* numbers deep. If <depth> is 0, there is no depth limit.
173			*/
174			void
175			rcsnum_cpy(const RCSNUM nsrc, RCSNUM ndst, u_int depth)
176			{
177			u_int len;
178
179			len = nsrc->rn_len;
180			if (depth != 0 && len > depth)
181			len = depth;
182
183			rcsnum_setsize(ndst, len);
184			/* Overflow checked in rcsnum_setsize(). */
185			(void)memcpy(ndst->rn_id, nsrc->rn_id,
186			len * sizeof(*(nsrc->rn_id)));
187			}
188
189			/*
190			* rcsnum_cmp()
191			*
192			* Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
193			* <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
194			* The <depth> argument specifies how many numbers deep should be checked for
195			* the result. A value of 0 means that the depth will be the maximum of the
196			* two numbers, so that a longer number is considered greater than a shorter
197			* number if they are equal up to the minimum length.
198			*/
199			int
200			rcsnum_cmp(const RCSNUM n1, const RCSNUM n2, u_int depth)
201			{
202			int res;
203			u_int i;
204			size_t slen;
205
206			slen = MINIMUM(n1->rn_len, n2->rn_len);
207			if (depth != 0 && slen > depth)
208			slen = depth;
209
210			for (i = 0; i < slen; i++) {
211			res = n1->rn_id[i] - n2->rn_id[i];
212			if (res < 0)
213			return (1);
214			else if (res > 0)
215			return (-1);
216			}
217
218			/* If an explicit depth was specified, and we've
219			* already checked up to depth, consider the
220			* revision numbers equal. */
221			if (depth != 0 && slen == depth)
222			return (0);
223			else if (n1->rn_len > n2->rn_len)
224			return (-1);
225			else if (n2->rn_len > n1->rn_len)
226			return (1);
227
228			return (0);
229			}
230
231			/*
232			* rcsnum_aton()
233			*
234			* Translate the string <str> containing a sequence of digits and periods into
235			* its binary representation, which is stored in <nump>. The address of the
236			* first byte not part of the number is stored in <ep> on return, if it is not
237			* NULL.
238			* Returns 0 on success, or -1 on failure.
239			*/
240			int
241			rcsnum_aton(const char str, const char ep, RCSNUM nump)
242			{
243			u_int32_t val;
244			const char *sp;
245			char *s;
246
247			if (nump->rn_id == NULL)
248			nump->rn_id = xmalloc(sizeof(*(nump->rn_id)));
249
250			nump->rn_len = 0;
251			nump->rn_id[0] = 0;
252
253			for (sp = str;; sp++) {
254			if (!isdigit((unsigned char)sp) && (sp != '.'))
255			break;
256
257			if (*sp == '.') {
258			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
259			rcs_errno = RCS_ERR_BADNUM;
260			goto rcsnum_aton_failed;
261			}
262
263			nump->rn_len++;
264			nump->rn_id = xreallocarray(nump->rn_id,
265			nump->rn_len + 1, sizeof(*(nump->rn_id)));
266			nump->rn_id[nump->rn_len] = 0;
267			continue;
268			}
269
270			val = (nump->rn_id[nump->rn_len] * 10) + (*sp - '0');
271			if (val > RCSNUM_MAXNUM)
272			errx(1, "RCSNUM overflow!");
273
274			nump->rn_id[nump->rn_len] = val;
275			}
276
277			if (ep != NULL)
278			*ep = sp;
279
280			/*
281			* Handle "magic" RCS branch numbers.
282			*
283			* What are they?
284			*
285			* Magic branch numbers have an extra .0. at the second farmost
286			* rightside of the branch number, so instead of having an odd
287			* number of dot-separated decimals, it will have an even number.
288			*
289			* Now, according to all the documentation I've found on the net
290			* about this, cvs does this for "efficiency reasons", I'd like
291			* to hear one.
292			*
293			* We just make sure we remove the .0. from in the branch number.
294			*
295			* XXX - for compatibility reasons with GNU cvs we _need_
296			* to skip this part for the 'log' command, apparently it does
297			* show the magic branches for an unknown and probably
298			* completely insane and not understandable reason in that output.
299			*
300			*/
301			if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0
302			&& !(rcsnum_flags & RCSNUM_NO_MAGIC)) {
303			/*
304			* Look for ".0.x" at the end of the branch number.
305			*/
306			if ((s = strrchr(str, '.')) != NULL) {
307			s--;
308			while (*s != '.')
309			s--;
310
311			/*
312			* If we have a "magic" branch, adjust it
313			* so the .0. is removed.
314			*/
315			if (!strncmp(s, RCS_MAGIC_BRANCH,
316			strlen(RCS_MAGIC_BRANCH))) {
317			nump->rn_id[nump->rn_len - 1] =
318			nump->rn_id[nump->rn_len];
319			nump->rn_len--;
320			}
321			}
322			}
323
324			/* We can't have a single-digit rcs number. */
325			if (nump->rn_len == 0) {
326			nump->rn_len++;
327			nump->rn_id = xreallocarray(nump->rn_id,
328			nump->rn_len + 1, sizeof(*(nump->rn_id)));
329			nump->rn_id[nump->rn_len] = 0;
330			}
331
332			nump->rn_len++;
333			return (nump->rn_len);
334
335			rcsnum_aton_failed:
336			nump->rn_len = 0;
337			free(nump->rn_id);
338			nump->rn_id = NULL;
339			return (-1);
340			}
341
342			/*
343			* rcsnum_inc()
344			*
345			* Increment the revision number specified in <num>.
346			* Returns a pointer to the <num> on success, or NULL on failure.
347			*/
348			RCSNUM *
349			rcsnum_inc(RCSNUM *num)
350			{
351			if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
352			return (NULL);
353			num->rn_id[num->rn_len - 1]++;
354			return (num);
355			}
356
357			/*
358			* rcsnum_revtobr()
359			*
360			* Retrieve the branch number associated with the revision number <num>.
361			* If <num> is a branch revision, the returned value will be the same
362			* number as the argument.
363			*/
364			RCSNUM *
365			rcsnum_revtobr(const RCSNUM *num)
366			{
367			RCSNUM *brnum;
368
369			if (num->rn_len < 2)
370			return (NULL);
371
372			brnum = rcsnum_alloc();
373			rcsnum_cpy(num, brnum, 0);
374
375			if (!RCSNUM_ISBRANCH(brnum))
376			brnum->rn_len--;
377
378			return (brnum);
379			}
380
381			/*
382			* rcsnum_brtorev()
383			*
384			* Retrieve the initial revision number associated with the branch number <num>.
385			* If <num> is a revision number, an error will be returned.
386			*/
387			RCSNUM *
388			rcsnum_brtorev(const RCSNUM *brnum)
389			{
390			RCSNUM *num;
391
392			if (!RCSNUM_ISBRANCH(brnum)) {
393			return (NULL);
394			}
395
396			num = rcsnum_alloc();
397			rcsnum_setsize(num, brnum->rn_len + 1);
398			rcsnum_cpy(brnum, num, brnum->rn_len);
399			num->rn_id[num->rn_len++] = 1;
400
401			return (num);
402			}
403
404			static void
405			rcsnum_setsize(RCSNUM *num, u_int len)
406			{
407			num->rn_id = xreallocarray(num->rn_id, len, sizeof(*(num->rn_id)));
408			num->rn_len = len;
409			}