Revert last commit due to changed semantics found by make release.

src/lib/libc/stdlib/realpath.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: realpath.c,v 1.17 2014/10/18 20:43:52 doug Exp $ */
+/*	$OpenBSD: realpath.c,v 1.18 2014/10/19 03:56:28 doug Exp $ */
 /*
  * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru>
  *
@@ -54,10 +54,6 @@ realpath(const char *path, char *resolved)
 	int serrno, slen, mem_allocated;
 	char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
 
-	if (path == NULL) {
-		errno = EINVAL;
-		return (NULL);
-	}
 	if (path[0] == '\0') {
 		errno = ENOENT;
 		return (NULL);
@@ -143,15 +139,22 @@ realpath(const char *path, char *resolved)
 		}
 
 		/*
-		 * Append the next path component and lstat() it.
+		 * Append the next path component and lstat() it. If
+		 * lstat() fails we still can return successfully if
+		 * there are no more path components left.
 		 */
 		resolved_len = strlcat(resolved, next_token, PATH_MAX);
 		if (resolved_len >= PATH_MAX) {
 			errno = ENAMETOOLONG;
 			goto err;
 		}
-		if (lstat(resolved, &sb) != 0)
+		if (lstat(resolved, &sb) != 0) {
+			if (errno == ENOENT && p == NULL) {
+				errno = serrno;
+				return (resolved);
+			}
 			goto err;
+		}
 		if (S_ISLNK(sb.st_mode)) {
 			if (symlinks++ > MAXSYMLINKS) {
 				errno = ELOOP;
@@ -193,9 +196,6 @@ realpath(const char *path, char *resolved)
 				}
 			}
 			left_len = strlcpy(left, symlink, sizeof(left));
-		} else if (!S_ISDIR(sb.st_mode) && p != NULL) {
-			errno = ENOTDIR;
-			goto err;
 		}
 	}