From: Jérémie Courrèges-Anglas <jca@wxcvbn.org>
Date: Wed, 27 Apr 2016 16:01:51 +0000 (+0200)
Subject: Provide fallback code for non-portable clearenv(3)
X-Git-Tag: samba-4.3.10~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14bd19899a952de1d5dde732a5a97e9f9d985a14;p=thirdparty%2Fsamba.git

Provide fallback code for non-portable clearenv(3)

clearenv(3) is a GNU extension that was rejected twice by POSIX,
without an easy, portable alternative.

As the dovecot project notes,
"""
environ = NULL crashes on OSX - and OpenBSD < 6.0
*environ = NULL doesn't work on FreeBSD 7.0
environ = emptyenv doesn't work on Haiku OS
environ = calloc should work everywhere
"""
(source: http://hg.dovecot.org/dovecot-2.0/file/48f90e7e92dc/src/lib/env-util.c)

Bug: https://bugzilla.samba.org/show_bug.cgi?id=11864
Signed-off-by: Jérémie Courrèges-Anglas <jca@wxcvbn.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Fri Apr 29 00:12:02 CEST 2016 on sn-devel-144

(cherry picked from commit f198abcbb3f6e8b26c697d3ded2caa1076ae018b)
---

diff --git a/source3/client/smbspool_krb5_wrapper.c b/source3/client/smbspool_krb5_wrapper.c
index e19fd92dc5b..89db5e05617 100644
--- a/source3/client/smbspool_krb5_wrapper.c
+++ b/source3/client/smbspool_krb5_wrapper.c
@@ -24,6 +24,7 @@
 #include "system/passwd.h"
 
 #include <errno.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <cups/backend.h>
@@ -195,7 +196,12 @@ int main(int argc, char *argv[])
 	 * Make sure we do not have LD_PRELOAD or other security relevant
 	 * environment variables set.
 	 */
+#ifdef HAVE_CLEARENV
 	clearenv();
+#else
+	extern char **environ;
+	environ = calloc(1, sizeof(*environ));
+#endif
 
 	CUPS_SMB_DEBUG("Setting KRB5CCNAME to '%s'", gen_cc);
 	setenv("KRB5CCNAME", gen_cc, 1);
diff --git a/source3/wscript b/source3/wscript
index e201710895d..beb3dab4445 100644
--- a/source3/wscript
+++ b/source3/wscript
@@ -92,7 +92,7 @@ def configure(conf):
     conf.CHECK_FUNCS('getpwnam', headers='sys/types.h pwd.h')
     conf.CHECK_FUNCS('fdopendir')
     conf.CHECK_FUNCS('fstatat')
-    conf.CHECK_FUNCS('getpwent_r setenv strcasecmp fcvt fcvtl')
+    conf.CHECK_FUNCS('getpwent_r setenv clearenv strcasecmp fcvt fcvtl')
     conf.CHECK_FUNCS('syslog vsyslog timegm setlocale')
     conf.CHECK_FUNCS_IN('nanosleep', 'rt')
     conf.CHECK_FUNCS('lutimes futimes utimensat futimens')