[PATCH] Make strlcpy/strlcat slightly easier to read.

[Igor Gnatenko]

Backport new changes from OpenBSD.

References: https://svnweb.freebsd.org/base?view=revision&revision=281135
Signed-off-by: Igor Gnatenko <i.gnatenko.brain at gmail.com>
---
 src/strlcat.c | 48 ++++++++++++++++++++++++------------------------
 src/strlcpy.c | 37 ++++++++++++++++++-------------------
 2 files changed, 42 insertions(+), 43 deletions(-)

diff --git a/src/strlcat.c b/src/strlcat.c
index 21c8afb..14c53a1 100644
--- a/src/strlcat.c
+++ b/src/strlcat.c
@@ -1,7 +1,7 @@
-/*	$OpenBSD: strlcat.c,v 1.12 2005/03/30 20:13:52 otto Exp $	*/
+/*	$OpenBSD: strlcat.c,v 1.15 2015/03/02 21:41:08 millert Exp $	*/
 
 /*
- * Copyright (c) 1998 Todd C. Miller <Todd.Miller at courtesan.com>
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller at courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -20,36 +20,36 @@
 #include <string.h>
 
 /*
- * Appends src to string dst of size siz (unlike strncat, siz is the
- * full size of dst, not space left).  At most siz-1 characters
- * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
- * Returns strlen(src) + MIN(siz, strlen(initial dst)).
- * If retval >= siz, truncation occurred.
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left).  At most dsize-1 characters
+ * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
  */
 size_t
-strlcat(char *dst, const char *src, size_t siz)
+strlcat(char *dst, const char *src, size_t dsize)
 {
-	char *d = dst;
-	const char *s = src;
-	size_t n = siz;
+	const char *odst = dst;
+	const char *osrc = src;
+	size_t n = dsize;
 	size_t dlen;
 
-	/* Find the end of dst and adjust bytes left but don't go past end */
-	while (n-- != 0 && *d != '\0')
-		d++;
-	dlen = d - dst;
-	n = siz - dlen;
+	/* Find the end of dst and adjust bytes left but don't go past end. */
+	while (n-- != 0 && *dst != '\0')
+		dst++;
+	dlen = dst - odst;
+	n = dsize - dlen;
 
-	if (n == 0)
-		return(dlen + strlen(s));
-	while (*s != '\0') {
-		if (n != 1) {
-			*d++ = *s;
+	if (n-- == 0)
+		return(dlen + strlen(src));
+	while (*src != '\0') {
+		if (n != 0) {
+			*dst++ = *src;
 			n--;
 		}
-		s++;
+		src++;
 	}
-	*d = '\0';
+	*dst = '\0';
 
-	return(dlen + (s - src));	/* count does not include NUL */
+	return(dlen + (src - osrc));	/* count does not include NUL */
 }
diff --git a/src/strlcpy.c b/src/strlcpy.c
index 1719d35..e9a7fe4 100644
--- a/src/strlcpy.c
+++ b/src/strlcpy.c
@@ -1,7 +1,7 @@
-/*	$OpenBSD: strlcpy.c,v 1.10 2005/08/08 08:05:37 espie Exp $	*/
+/*	$OpenBSD: strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $	*/
 
 /*
- * Copyright (c) 1998 Todd C. Miller <Todd.Miller at courtesan.com>
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller at courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -20,32 +20,31 @@
 #include <string.h>
 
 /*
- * Copy src to string dst of size siz.  At most siz-1 characters
- * will be copied.  Always NUL terminates (unless siz == 0).
- * Returns strlen(src); if retval >= siz, truncation occurred.
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
  */
 size_t
-strlcpy(char *dst, const char *src, size_t siz)
+strlcpy(char *dst, const char *src, size_t dsize)
 {
-	char *d = dst;
-	const char *s = src;
-	size_t n = siz;
+	const char *osrc = src;
+	size_t nleft = dsize;
 
-	/* Copy as many bytes as will fit */
-	if (n != 0) {
-		while (--n != 0) {
-			if ((*d++ = *s++) == '\0')
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
 				break;
 		}
 	}
 
-	/* Not enough room in dst, add NUL and traverse rest of src */
-	if (n == 0) {
-		if (siz != 0)
-			*d = '\0';		/* NUL-terminate dst */
-		while (*s++)
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
 			;
 	}
 
-	return(s - src - 1);	/* count does not include NUL */
+	return(src - osrc - 1);	/* count does not include NUL */
 }
-- 
2.9.0