getwd(3): don't malloc space for buf if it is NULL

The 4.3BSD getwd(3) did not malloc space, use __getcwd(2) directly
so the compat function doesn't either.  OK deraadt@

diff --git a/lib/libc/compat-43/getwd.c b/lib/libc/compat-43/getwd.c
index 3062d46..2ae1368 100644 (file)
--- a/lib/libc/compat-43/getwd.c
+++ b/lib/libc/compat-43/getwd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: getwd.c,v 1.12 2017/11/28 06:55:49 tb Exp $ */
+/*     $OpenBSD: getwd.c,v 1.13 2021/12/16 19:12:43 millert Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -34,15 +34,17 @@
 #include <string.h>
 #include <unistd.h>
 
+int __getcwd(char *buf, size_t len);
+PROTO_NORMAL(__getcwd);
+
 char *
 getwd(char *buf)
 {
-       char *p;
-
-       if ((p = getcwd(buf, PATH_MAX)))
-               return(p);
-       strlcpy(buf, strerror(errno), PATH_MAX);
-       return(NULL);
+       if (__getcwd(buf, PATH_MAX) == -1) {
+               strlcpy(buf, strerror(errno), PATH_MAX);
+               return NULL;
+       }
+       return buf;
 }
 
 __warn_references(getwd,