1) Although unpublished version of standard

http://austingroupbugs.net/view.php?id=385#c713
(Resolved state) recommend this way for the current standard (called
"earlier" in the text)

"However, earlier versions of this standard did not require this, and the
same example had to be written as:

    // buf was obtained by malloc(buflen)
    ret = write(fd, buf, buflen);
    if (ret < 0) {
        int save = errno;
        free(buf);
        errno = save;
        return ret;
    }
"

from feedback I have for previous commit it seems that many people prefer
to avoid mass code change needed for current standard compliance
and prefer to track unpublished standard instead, which requires now
that free() itself must save errno, not its usage code.

So, I back out "save errno across free()" part of previous commit,
and will fill PR for changing free() isntead.

2) Remove now unused serrno.

MFC after:      1 week

1 files changed, 6 insertions, 17 deletions

diff --git a/lib/libc/stdlib/realpath.c b/lib/libc/stdlib/realpath.c
index 185dbb6..aded9b2 100644
--- a/lib/libc/stdlib/realpath.c
+++ b/lib/libc/stdlib/realpath.c
@@ -54,7 +54,7 @@ realpath(const char * __restrict path, char * __restrict resolved)
 	char *p, *q, *s;
 	size_t left_len, resolved_len;
 	unsigned symlinks;
-	int m, serrno, slen;
+	int m, slen;
 	char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
 
 	if (path == NULL) {
@@ -82,11 +82,9 @@ realpath(const char * __restrict path, char * __restrict resolved)
 		left_len = strlcpy(left, path + 1, sizeof(left));
 	} else {
 		if (getcwd(resolved, PATH_MAX) == NULL) {
-			if (m) {
-				serrno = errno;
+			if (m)
 				free(resolved);
-				errno = serrno;
-			} else {
+			else {
 				resolved[0] = '.';
 				resolved[1] = '\0';
 			}
@@ -144,11 +142,8 @@ realpath(const char * __restrict path, char * __restrict resolved)
 			 * occurence to not implement lookahead.
 			 */
 			if (lstat(resolved, &sb) != 0) {
-				if (m) {
-					serrno = errno;
+				if (m)
 					free(resolved);
-					errno = serrno;
-				}
 				return (NULL);
 			}
 			if (!S_ISDIR(sb.st_mode)) {
@@ -188,11 +183,8 @@ realpath(const char * __restrict path, char * __restrict resolved)
 		if (lstat(resolved, &sb) != 0) {
 			if (errno != ENOENT || p != NULL)
 				errno = ENOTDIR;
-			if (m) {
-				serrno = errno;
+			if (m)
 				free(resolved);
-				errno = serrno;
-			}
 			return (NULL);
 		}
 		if (S_ISLNK(sb.st_mode)) {
@@ -204,11 +196,8 @@ realpath(const char * __restrict path, char * __restrict resolved)
 			}
 			slen = readlink(resolved, symlink, sizeof(symlink) - 1);
 			if (slen < 0) {
-				if (m) {
-					serrno = errno;
+				if (m)
 					free(resolved);
-					errno = serrno;
-				}
 				return (NULL);
 			}
 			symlink[slen] = '\0';