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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/rcs/rcsnum.c	Lines:	0	121	0.0 %
Date:	2016-12-06	Branches:	0	80	0.0 %


/*	$OpenBSD: rcsnum.c,v 1.18 2015/11/02 16:45:21 nicm 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 <stdlib.h>
#include <string.h>
#include <limits.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)
{
	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, 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)
		*(const char **)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 1.18 2015/11/02 16:45:21 nicm 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 <stdlib.h>
30			#include <string.h>
31			#include <limits.h>
32
33			#include "rcs.h"
34			#include "xmalloc.h"
35
36			#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
37
38			static void rcsnum_setsize(RCSNUM *, u_int);
39			static char rcsnum_itoa(u_int16_t, char , size_t);
40
41			int rcsnum_flags;
42
43			/*
44			* rcsnum_alloc()
45			*
46			* Allocate an RCS number structure and return a pointer to it.
47			*/
48			RCSNUM *
49			rcsnum_alloc(void)
50			{
51			RCSNUM *rnp;
52
53			rnp = xmalloc(sizeof(*rnp));
54			rnp->rn_len = 0;
55			rnp->rn_id = NULL;
56
57			return (rnp);
58			}
59
60			/*
61			* rcsnum_addmagic()
62			*
63			* Adds a magic branch number to an RCS number.
64			* Returns 0 on success, or -1 on failure.
65			*/
66			int
67			rcsnum_addmagic(RCSNUM *rn)
68			{
69			if (!rn->rn_len \|\| rn->rn_len > RCSNUM_MAXLEN - 1)
70			return -1;
71			rcsnum_setsize(rn, rn->rn_len + 1);
72			rn->rn_id[rn->rn_len - 1] = rn->rn_id[rn->rn_len - 2];
73			rn->rn_id[rn->rn_len - 2] = 0;
74
75			return 0;
76			}
77
78			/*
79			* rcsnum_parse()
80			*
81			* Parse a string specifying an RCS number and return the corresponding RCSNUM.
82			*/
83			RCSNUM *
84			rcsnum_parse(const char *str)
85			{
86			char *ep;
87			RCSNUM *num;
88
89			num = rcsnum_alloc();
90			if (rcsnum_aton(str, &ep, num) < 0 \|\| *ep != '\0') {
91			rcsnum_free(num);
92			num = NULL;
93			if (*ep != '\0')
94			rcs_errno = RCS_ERR_BADNUM;
95			}
96
97			return (num);
98			}
99
100			/*
101			* rcsnum_free()
102			*
103			* Free an RCSNUM structure previously allocated with rcsnum_alloc().
104			*/
105			void
106			rcsnum_free(RCSNUM *rn)
107			{
108			if (rn == NULL)
109			return;
110			free(rn->rn_id);
111			free(rn);
112			}
113
114			/*
115			* rcsnum_tostr()
116			*
117			* Format the RCS number <nump> into a human-readable dot-separated
118			* representation and store the resulting string in <buf>, which is of size
119			* <blen>.
120			* Returns a pointer to the start of <buf>. On failure <buf> is set to
121			* an empty string.
122			*/
123			char *
124			rcsnum_tostr(const RCSNUM nump, char buf, size_t blen)
125			{
126			u_int i;
127			char tmp[8];
128
129			if (nump == NULL \|\| nump->rn_len == 0) {
130			buf[0] = '\0';
131			return (buf);
132			}
133
134			if (strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen) >= blen)
135			errx(1, "rcsnum_tostr: string truncated");
136			for (i = 1; i < nump->rn_len; i++) {
137			const char *str;
138
139			str = rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp));
140			if (strlcat(buf, ".", blen) >= blen \|\|
141			strlcat(buf, str, blen) >= blen)
142			errx(1, "rcsnum_tostr: string truncated");
143			}
144
145			return (buf);
146			}
147
148			static char *
149			rcsnum_itoa(u_int16_t num, char *buf, size_t len)
150			{
151			u_int16_t i;
152			char *p;
153
154			if (num == 0)
155			return "0";
156
157			p = buf + len - 1;
158			i = num;
159			bzero(buf, len);
160			while (i) {
161			*--p = '0' + (i % 10);
162			i /= 10;
163			}
164			return (p);
165			}
166
167			/*
168			* rcsnum_cpy()
169			*
170			* Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
171			* numbers deep. If <depth> is 0, there is no depth limit.
172			*/
173			void
174			rcsnum_cpy(const RCSNUM nsrc, RCSNUM ndst, u_int depth)
175			{
176			u_int len;
177
178			len = nsrc->rn_len;
179			if (depth != 0 && len > depth)
180			len = depth;
181
182			rcsnum_setsize(ndst, len);
183			/* Overflow checked in rcsnum_setsize(). */
184			(void)memcpy(ndst->rn_id, nsrc->rn_id,
185			len * sizeof(*(nsrc->rn_id)));
186			}
187
188			/*
189			* rcsnum_cmp()
190			*
191			* Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
192			* <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
193			* The <depth> argument specifies how many numbers deep should be checked for
194			* the result. A value of 0 means that the depth will be the maximum of the
195			* two numbers, so that a longer number is considered greater than a shorter
196			* number if they are equal up to the minimum length.
197			*/
198			int
199			rcsnum_cmp(const RCSNUM n1, const RCSNUM n2, u_int depth)
200			{
201			int res;
202			u_int i;
203			size_t slen;
204
205			slen = MINIMUM(n1->rn_len, n2->rn_len);
206			if (depth != 0 && slen > depth)
207			slen = depth;
208
209			for (i = 0; i < slen; i++) {
210			res = n1->rn_id[i] - n2->rn_id[i];
211			if (res < 0)
212			return (1);
213			else if (res > 0)
214			return (-1);
215			}
216
217			/* If an explicit depth was specified, and we've
218			* already checked up to depth, consider the
219			* revision numbers equal. */
220			if (depth != 0 && slen == depth)
221			return (0);
222			else if (n1->rn_len > n2->rn_len)
223			return (-1);
224			else if (n2->rn_len > n1->rn_len)
225			return (1);
226
227			return (0);
228			}
229
230			/*
231			* rcsnum_aton()
232			*
233			* Translate the string <str> containing a sequence of digits and periods into
234			* its binary representation, which is stored in <nump>. The address of the
235			* first byte not part of the number is stored in <ep> on return, if it is not
236			* NULL.
237			* Returns 0 on success, or -1 on failure.
238			*/
239			int
240			rcsnum_aton(const char str, char ep, RCSNUM nump)
241			{
242			u_int32_t val;
243			const char *sp;
244			char *s;
245
246			if (nump->rn_id == NULL)
247			nump->rn_id = xmalloc(sizeof(*(nump->rn_id)));
248
249			nump->rn_len = 0;
250			nump->rn_id[0] = 0;
251
252			for (sp = str;; sp++) {
253			if (!isdigit((unsigned char)sp) && (sp != '.'))
254			break;
255
256			if (*sp == '.') {
257			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
258			rcs_errno = RCS_ERR_BADNUM;
259			goto rcsnum_aton_failed;
260			}
261
262			nump->rn_len++;
263			nump->rn_id = xreallocarray(nump->rn_id,
264			nump->rn_len + 1, sizeof(*(nump->rn_id)));
265			nump->rn_id[nump->rn_len] = 0;
266			continue;
267			}
268
269			val = (nump->rn_id[nump->rn_len] * 10) + (*sp - '0');
270			if (val > RCSNUM_MAXNUM)
271			errx(1, "RCSNUM overflow!");
272
273			nump->rn_id[nump->rn_len] = val;
274			}
275
276			if (ep != NULL)
277			(const char *)ep = sp;
278
279			/*
280			* Handle "magic" RCS branch numbers.
281			*
282			* What are they?
283			*
284			* Magic branch numbers have an extra .0. at the second farmost
285			* rightside of the branch number, so instead of having an odd
286			* number of dot-separated decimals, it will have an even number.
287			*
288			* Now, according to all the documentation I've found on the net
289			* about this, cvs does this for "efficiency reasons", I'd like
290			* to hear one.
291			*
292			* We just make sure we remove the .0. from in the branch number.
293			*
294			* XXX - for compatibility reasons with GNU cvs we _need_
295			* to skip this part for the 'log' command, apparently it does
296			* show the magic branches for an unknown and probably
297			* completely insane and not understandable reason in that output.
298			*
299			*/
300			if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0
301			&& !(rcsnum_flags & RCSNUM_NO_MAGIC)) {
302			/*
303			* Look for ".0.x" at the end of the branch number.
304			*/
305			if ((s = strrchr(str, '.')) != NULL) {
306			s--;
307			while (*s != '.')
308			s--;
309
310			/*
311			* If we have a "magic" branch, adjust it
312			* so the .0. is removed.
313			*/
314			if (!strncmp(s, RCS_MAGIC_BRANCH,
315			strlen(RCS_MAGIC_BRANCH))) {
316			nump->rn_id[nump->rn_len - 1] =
317			nump->rn_id[nump->rn_len];
318			nump->rn_len--;
319			}
320			}
321			}
322
323			/* We can't have a single-digit rcs number. */
324			if (nump->rn_len == 0) {
325			nump->rn_len++;
326			nump->rn_id = xreallocarray(nump->rn_id,
327			nump->rn_len + 1, sizeof(*(nump->rn_id)));
328			nump->rn_id[nump->rn_len] = 0;
329			}
330
331			nump->rn_len++;
332			return (nump->rn_len);
333
334			rcsnum_aton_failed:
335			nump->rn_len = 0;
336			free(nump->rn_id);
337			nump->rn_id = NULL;
338			return (-1);
339			}
340
341			/*
342			* rcsnum_inc()
343			*
344			* Increment the revision number specified in <num>.
345			* Returns a pointer to the <num> on success, or NULL on failure.
346			*/
347			RCSNUM *
348			rcsnum_inc(RCSNUM *num)
349			{
350			if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
351			return (NULL);
352			num->rn_id[num->rn_len - 1]++;
353			return (num);
354			}
355
356			/*
357			* rcsnum_revtobr()
358			*
359			* Retrieve the branch number associated with the revision number <num>.
360			* If <num> is a branch revision, the returned value will be the same
361			* number as the argument.
362			*/
363			RCSNUM *
364			rcsnum_revtobr(const RCSNUM *num)
365			{
366			RCSNUM *brnum;
367
368			if (num->rn_len < 2)
369			return (NULL);
370
371			brnum = rcsnum_alloc();
372			rcsnum_cpy(num, brnum, 0);
373
374			if (!RCSNUM_ISBRANCH(brnum))
375			brnum->rn_len--;
376
377			return (brnum);
378			}
379
380			/*
381			* rcsnum_brtorev()
382			*
383			* Retrieve the initial revision number associated with the branch number <num>.
384			* If <num> is a revision number, an error will be returned.
385			*/
386			RCSNUM *
387			rcsnum_brtorev(const RCSNUM *brnum)
388			{
389			RCSNUM *num;
390
391			if (!RCSNUM_ISBRANCH(brnum)) {
392			return (NULL);
393			}
394
395			num = rcsnum_alloc();
396			rcsnum_setsize(num, brnum->rn_len + 1);
397			rcsnum_cpy(brnum, num, brnum->rn_len);
398			num->rn_id[num->rn_len++] = 1;
399
400			return (num);
401			}
402
403			static void
404			rcsnum_setsize(RCSNUM *num, u_int len)
405			{
406			num->rn_id = xreallocarray(num->rn_id, len, sizeof(*(num->rn_id)));
407			num->rn_len = len;
408			}