svn commit: r269453 - stable/10/lib/libc/gen

[Marcel Moolenaar]

Author: marcel
Date: Sun Aug  3 01:51:48 2014
New Revision: 269453
URL: http://svnweb.freebsd.org/changeset/base/269453

Log:
  MFC 264161: Handle the fact that the getlogin_basic() function can return
  a 0 status with a NULL pointer for the login name (result).
  
  Obtained from:	Juniper Networks, Inc.

Modified:
  stable/10/lib/libc/gen/getlogin.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/lib/libc/gen/getlogin.c
==============================================================================
--- stable/10/lib/libc/gen/getlogin.c	Sun Aug  3 00:35:10 2014	(r269452)
+++ stable/10/lib/libc/gen/getlogin.c	Sun Aug  3 01:51:48 2014	(r269453)
@@ -87,11 +87,16 @@ getlogin_r(char *logname, int namelen)
 	char	*result;
 	int	len;
 	int	status;
-	
+
+	if (namelen < 1)
+		return (ERANGE);
+	logname[0] = '\0';
+
 	THREAD_LOCK();
 	result = getlogin_basic(&status);
-	if (status == 0) {
-		if ((len = strlen(result) + 1) > namelen)
+	if (status == 0 && result != NULL) {
+		len = strlen(result) + 1;
+		if (len > namelen)
 			status = ERANGE;
 		else
 			strncpy(logname, result, len);