diff --git a/mysql-test/r/acl_roles_set_role-database-recursive.result b/mysql-test/r/acl_roles_set_role-database-recursive.result
index 0038c82843c..04067afa253 100644
--- a/mysql-test/r/acl_roles_set_role-database-recursive.result
+++ b/mysql-test/r/acl_roles_set_role-database-recursive.result
@@ -31,7 +31,7 @@ select * from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -44,7 +44,7 @@ localhost	test_user	test_role2
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 select * from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 set role test_role2;
diff --git a/mysql-test/r/acl_roles_set_role-database-simple.result b/mysql-test/r/acl_roles_set_role-database-simple.result
index 32575638e4c..1cc3aba1a39 100644
--- a/mysql-test/r/acl_roles_set_role-database-simple.result
+++ b/mysql-test/r/acl_roles_set_role-database-simple.result
@@ -18,7 +18,7 @@ select * from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -36,7 +36,7 @@ use mysql;
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 use mysql;
 ERROR 42000: Access denied for user 'test_user'@'localhost' to database 'mysql'
 select * from mysql.roles_mapping;
diff --git a/mysql-test/r/acl_roles_set_role-multiple-role.result b/mysql-test/r/acl_roles_set_role-multiple-role.result
index 0aa105ec0d4..d4a432d6c03 100644
--- a/mysql-test/r/acl_roles_set_role-multiple-role.result
+++ b/mysql-test/r/acl_roles_set_role-multiple-role.result
@@ -71,7 +71,7 @@ GRANT r_sel TO 'test_user'@'localhost'
 GRANT r_upd TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role r_sel;
 select current_user(), current_role();
 current_user()	current_role()
@@ -131,7 +131,7 @@ flush privileges;
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 flush privileges;
 ERROR 42000: Access denied; you need (at least one of) the RELOAD privilege(s) for this operation
 set role r_ins;
diff --git a/mysql-test/r/acl_roles_set_role-recursive.result b/mysql-test/r/acl_roles_set_role-recursive.result
index 505e1f5f730..864616cf255 100644
--- a/mysql-test/r/acl_roles_set_role-recursive.result
+++ b/mysql-test/r/acl_roles_set_role-recursive.result
@@ -37,7 +37,7 @@ GRANT USAGE ON *.* TO 'test_user'@'localhost'
 GRANT test_role1 TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -62,7 +62,7 @@ GRANT test_role2 TO 'test_role1'
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 show grants;
 Grants for test_user@localhost
 GRANT USAGE ON *.* TO 'test_user'@'localhost'
@@ -77,7 +77,7 @@ set role test_role2;
 ERROR HY000: The role 'test_role2' has not been granted or is invalid.
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 show grants;
 Grants for test_user@localhost
 GRANT USAGE ON *.* TO 'test_user'@'localhost'
@@ -112,7 +112,7 @@ GRANT test_role2 TO 'test_role1'
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 show grants;
 Grants for test_user@localhost
 GRANT USAGE ON *.* TO 'test_user'@'localhost'
diff --git a/mysql-test/r/acl_roles_set_role-routine-simple.result b/mysql-test/r/acl_roles_set_role-routine-simple.result
index 2ca1a60b324..a57bfb9b3f2 100644
--- a/mysql-test/r/acl_roles_set_role-routine-simple.result
+++ b/mysql-test/r/acl_roles_set_role-routine-simple.result
@@ -42,7 +42,7 @@ use mysql;
 ERROR 42000: Access denied for user 'test_user'@'localhost' to database 'mysql'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -68,7 +68,7 @@ GRANT test_role3 TO 'test_user'@'localhost'
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 show grants;
 Grants for test_user@localhost
 GRANT USAGE ON *.* TO 'test_user'@'localhost'
diff --git a/mysql-test/r/acl_roles_set_role-simple.result b/mysql-test/r/acl_roles_set_role-simple.result
index aa68052ae18..cadc63624aa 100644
--- a/mysql-test/r/acl_roles_set_role-simple.result
+++ b/mysql-test/r/acl_roles_set_role-simple.result
@@ -24,7 +24,7 @@ GRANT USAGE ON *.* TO 'test_user'@'localhost'
 GRANT test_role1 TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -40,7 +40,7 @@ localhost	test_user	test_role1
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 select * from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 delete from mysql.user where user='test_role1';
diff --git a/mysql-test/r/acl_roles_set_role-table-column-priv.result b/mysql-test/r/acl_roles_set_role-table-column-priv.result
index e5b43b0ded4..5e21dab3787 100644
--- a/mysql-test/r/acl_roles_set_role-table-column-priv.result
+++ b/mysql-test/r/acl_roles_set_role-table-column-priv.result
@@ -26,7 +26,7 @@ GRANT USAGE ON *.* TO 'test_user'@'localhost'
 GRANT test_role1 TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -57,7 +57,7 @@ use mysql;
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 select RoleFk from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 drop user 'test_user'@'localhost';
diff --git a/mysql-test/r/acl_roles_set_role-table-simple.result b/mysql-test/r/acl_roles_set_role-table-simple.result
index 780a416437a..01d84757ea4 100644
--- a/mysql-test/r/acl_roles_set_role-table-simple.result
+++ b/mysql-test/r/acl_roles_set_role-table-simple.result
@@ -26,7 +26,7 @@ GRANT USAGE ON *.* TO 'test_user'@'localhost'
 GRANT test_role1 TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -55,7 +55,7 @@ use mysql;
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 select * from mysql.roles_mapping;
 ERROR 42000: SELECT command denied to user 'test_user'@'localhost' for table 'roles_mapping'
 drop user 'test_user'@'localhost';
diff --git a/mysql-test/r/acl_roles_show_grants.result b/mysql-test/r/acl_roles_show_grants.result
index 1e0c1626b75..cfe93392f41 100644
--- a/mysql-test/r/acl_roles_show_grants.result
+++ b/mysql-test/r/acl_roles_show_grants.result
@@ -34,7 +34,7 @@ GRANT test_role1 TO 'test_user'@'localhost'
 GRANT test_role2 TO 'test_user'@'localhost'
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 set role test_role1;
 select current_user(), current_role();
 current_user()	current_role()
@@ -51,7 +51,7 @@ GRANT test_role2 TO 'test_user'@'localhost'
 set role none;
 select current_user(), current_role();
 current_user()	current_role()
-test_user@localhost	NONE
+test_user@localhost	NULL
 show grants;
 Grants for test_user@localhost
 GRANT USAGE ON *.* TO 'test_user'@'localhost'
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 4f2c10c37ef..4f85dde1831 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -2345,19 +2345,16 @@ bool Item_func_current_role::fix_fields(THD *thd, Item **ref)
   Security_context *ctx= context->security_ctx
                           ? context->security_ctx : thd->security_ctx;
 
-  LEX_STRING role;
   if (ctx->priv_role[0])
   {
-    role.str= ctx->priv_role;
-    role.length= strlen(role.str);
+    if (str_value.copy(ctx->priv_role, strlen(ctx->priv_role),
+                       system_charset_info))
+      return 1;
+
+    str_value.mark_as_const();
+    return 0;
   }
-  else
-    role= none_role;
-
-  if (str_value.copy(role.str, role.length, system_charset_info))
-    return 1;
-
-  str_value.mark_as_const();
+  null_value= maybe_null= 1;
   return 0;
 }