4 files changed, 42 insertions, 1 deletions
diff --git a/source4/lib/replace/README b/source4/lib/replace/README
index 21cd0051c7..6610b7c279 100644
--- a/source4/lib/replace/README
+++ b/source4/lib/replace/README
@@ -21,6 +21,7 @@ setlinebuf
 vsyslog
 timegm
 setenv
+unsetenv
 strndup
 strnlen
 waitpid
diff --git a/source4/lib/replace/libreplace.m4 b/source4/lib/replace/libreplace.m4
index 805cdc6cb5..b5f931c7e4 100644
--- a/source4/lib/replace/libreplace.m4
+++ b/source4/lib/replace/libreplace.m4
@@ -263,7 +263,8 @@ AC_CHECK_HEADERS([sys/param.h limits.h])
 AC_CHECK_TYPE(comparison_fn_t, 
 [AC_DEFINE(HAVE_COMPARISON_FN_T, 1,[Whether or not we have comparison_fn_t])])
 
-AC_CHECK_FUNCS(strnlen setenv)
+AC_CHECK_FUNCS(setenv unsetenv)
+AC_CHECK_FUNCS(strnlen)
 AC_CHECK_FUNCS(strtoull __strtoull strtouq strtoll __strtoll strtoq)
 
 # this test disabled as we don't actually need __VA_ARGS__ yet
diff --git a/source4/lib/replace/replace.c b/source4/lib/replace/replace.c
index 9e6c75bd35..486c1c5e13 100644
--- a/source4/lib/replace/replace.c
+++ b/source4/lib/replace/replace.c
@@ -590,6 +590,40 @@ int rep_setenv(const char *name, const char *value, int overwrite)
 }
 #endif
 
+#ifndef HAVE_UNSETENV
+int rep_unsetenv(const char *name)
+{
+	char *p;
+	size_t l1;
+	int ret;
+
+	if (!getenv(name)) {
+		return 0;
+	}
+
+	l1 = strlen(name);
+
+	p = malloc(l1+1);
+	if (p == NULL) {
+		return -1;
+	}
+	memcpy(p, name, l1);
+	p[l1] = 0;
+
+	/*
+	 * use using "name" here unsets the var
+	 *
+	 * "name=" would set it to an empty string..
+	 */
+	ret = putenv(p);
+	if (ret != 0) {
+		free(p);
+	}
+
+	return ret;
+}
+#endif
+
 #ifndef HAVE_SOCKETPAIR
 int rep_socketpair(int d, int type, int protocol, int sv[2])
 {
diff --git a/source4/lib/replace/replace.h b/source4/lib/replace/replace.h
index 5667644025..cae9d80178 100644
--- a/source4/lib/replace/replace.h
+++ b/source4/lib/replace/replace.h
@@ -140,6 +140,11 @@ size_t rep_strnlen(const char *s, size_t n);
 int rep_setenv(const char *name, const char *value, int overwrite); 
 #endif
 
+#ifndef HAVE_UNSETENV
+#define unsetenv rep_unsetenv
+int rep_unsetenv(const char *name, const char *value, int overwrite); 
+#endif
+
 #ifndef HAVE_SETEUID
 #define seteuid rep_seteuid
 int rep_seteuid(uid_t);