diff --git a/mysql-test/r/skip_grants.result b/mysql-test/r/skip_grants.result
index 6714fa9d217..58ced16acac 100644
--- a/mysql-test/r/skip_grants.result
+++ b/mysql-test/r/skip_grants.result
@@ -1,30 +1,60 @@
-drop table if exists t1,v1;
-drop view if exists t1,v1;
-drop procedure if exists f1;
 use test;
-create procedure f1() select 1;
-drop procedure f1;
-create table t1 (a int);
-create definer='user'@'host' sql security definer view v1 as select * from t1;
-drop view v1;
-drop table t1;
-drop function if exists f1;
-Warnings:
-Note	1305	FUNCTION f1 does not exist
 DROP VIEW IF EXISTS v1;
 DROP VIEW IF EXISTS v2;
+DROP VIEW IF EXISTS v3;
 DROP TABLE IF EXISTS t1;
+DROP PROCEDURE IF EXISTS p1;
+DROP PROCEDURE IF EXISTS p2;
+DROP PROCEDURE IF EXISTS p3;
+DROP FUNCTION IF EXISTS f1;
+DROP FUNCTION IF EXISTS f2;
+DROP FUNCTION IF EXISTS f3;
 CREATE TABLE t1(c INT);
 CREATE TRIGGER t1_bi BEFORE INSERT ON t1
 FOR EACH ROW
 SET @a = 1;
 CREATE VIEW v1 AS SELECT * FROM t1;
+CREATE PROCEDURE p1()
+SELECT 1;
+CREATE FUNCTION f1() RETURNS INT
+RETURN 1;
 CREATE DEFINER=a@b TRIGGER ti_ai AFTER INSERT ON t1
 FOR EACH ROW
 SET @b = 1;
 CREATE DEFINER=a@b VIEW v2 AS SELECT * FROM t1;
+CREATE DEFINER=a@b PROCEDURE p2()
+SELECT 2;
+CREATE DEFINER=a@b FUNCTION f2() RETURNS INT
+RETURN 2;
+CREATE DEFINER=a@'' TRIGGER ti_bu BEFORE UPDATE ON t1
+FOR EACH ROW
+SET @c = 1;
+CREATE DEFINER=a@'' VIEW v3 AS SELECT * FROM t1;
+CREATE DEFINER=a@'' PROCEDURE p3()
+SELECT 3;
+CREATE DEFINER=a@'' FUNCTION f3() RETURNS INT
+RETURN 3;
+SHOW CREATE VIEW v3;
+View	Create View
+v3	CREATE ALGORITHM=UNDEFINED DEFINER=`a`@`` SQL SECURITY DEFINER VIEW `v3` AS select `t1`.`c` AS `c` from `t1`
+SHOW CREATE PROCEDURE p3;
+Procedure	sql_mode	Create Procedure
+p3		CREATE DEFINER=`a`@`` PROCEDURE `p3`()
+SELECT 3
+SHOW CREATE FUNCTION f3;
+Function	sql_mode	Create Function
+f3		CREATE DEFINER=`a`@`` FUNCTION `f3`() RETURNS int(11)
+RETURN 3
 DROP TRIGGER t1_bi;
 DROP TRIGGER ti_ai;
+DROP TRIGGER ti_bu;
 DROP VIEW v1;
 DROP VIEW v2;
+DROP VIEW v3;
 DROP TABLE t1;
+DROP PROCEDURE p1;
+DROP PROCEDURE p2;
+DROP PROCEDURE p3;
+DROP FUNCTION f1;
+DROP FUNCTION f2;
+DROP FUNCTION f3;
diff --git a/mysql-test/r/sp.result b/mysql-test/r/sp.result
index 6521a2b67b7..f31facf6196 100644
--- a/mysql-test/r/sp.result
+++ b/mysql-test/r/sp.result
@@ -4796,4 +4796,20 @@ i
 0
 drop table t3|
 drop procedure bug16887|
+create table t3 (f1 int, f2 varchar(3), primary key(f1)) engine=innodb|
+insert into t3 values (1,'aaa'),(2,'bbb'),(3,'ccc')|
+CREATE FUNCTION bug13575 ( p1 integer ) 
+returns varchar(3) 
+BEGIN 
+DECLARE v1 VARCHAR(10) DEFAULT null;
+SELECT f2 INTO v1 FROM t3 WHERE f1 = p1; 
+RETURN v1;
+END|
+select distinct f1, bug13575(f1) from t3 order by f1|
+f1	bug13575(f1)
+1	aaa
+2	bbb
+3	ccc
+drop function bug13575;
+drop table t3|
 drop table t1,t2;
diff --git a/mysql-test/t/skip_grants.test b/mysql-test/t/skip_grants.test
index 93e052d8c71..6dda97fcf8a 100644
--- a/mysql-test/t/skip_grants.test
+++ b/mysql-test/t/skip_grants.test
@@ -1,37 +1,18 @@
 # This tests not performed with embedded server
 -- source include/not_embedded.inc
 
---disable_warnings
-drop table if exists t1,v1;
-drop view if exists t1,v1;
-drop procedure if exists f1;
---enable_warnings
 use test;
 
-#
-# Test that we can create and drop procedure without warnings
-# see bug#9993
-#
-create procedure f1() select 1;
-drop procedure f1;
-
-#
-# BUG#13504: creation view with DEFINER clause if --skip-grant-tables
-#
-create table t1 (a int);
-create definer='user'@'host' sql security definer view v1 as select * from t1;
-drop view v1;
-drop table t1;
-
-# BUG#17595: DROP FUNCTION IF EXISTS f1 crashes server
-drop function if exists f1;
-
 #
 # BUG#16777: Can not create trigger nor view w/o definer if --skip-grant-tables
 # specified
 #
-# Also, a test that we can create VIEW if privileges check switched off has
-# been moved here.
+# Also, the following test cases have been moved here:
+#   - test that we can create VIEW if privileges check switched off has been
+#     moved here;
+#   - test that we can create and drop procedure without warnings (BUG#9993);
+#   - BUG#17595: "DROP FUNCTION IF EXISTS" crashes server;
+#   - BUG#13504: creation view with DEFINER clause if --skip-grant-tables
 #
 
 # Prepare.
@@ -40,33 +21,90 @@ drop function if exists f1;
 
 DROP VIEW IF EXISTS v1;
 DROP VIEW IF EXISTS v2;
+DROP VIEW IF EXISTS v3;
 
 DROP TABLE IF EXISTS t1;
 
+DROP PROCEDURE IF EXISTS p1;
+DROP PROCEDURE IF EXISTS p2;
+DROP PROCEDURE IF EXISTS p3;
+
+DROP FUNCTION IF EXISTS f1;
+DROP FUNCTION IF EXISTS f2;
+DROP FUNCTION IF EXISTS f3;
+
 --enable_warnings
 
 # Test case.
 
 CREATE TABLE t1(c INT);
 
+# - try to create with implicit definer (definer would be ''@'');
+
 CREATE TRIGGER t1_bi BEFORE INSERT ON t1
   FOR EACH ROW
     SET @a = 1;
 
 CREATE VIEW v1 AS SELECT * FROM t1;
 
+CREATE PROCEDURE p1()
+  SELECT 1;
+
+CREATE FUNCTION f1() RETURNS INT
+  RETURN 1;
+
+# - try to create with explicit definer;
+
 CREATE DEFINER=a@b TRIGGER ti_ai AFTER INSERT ON t1
   FOR EACH ROW
     SET @b = 1;
 
 CREATE DEFINER=a@b VIEW v2 AS SELECT * FROM t1;
 
+CREATE DEFINER=a@b PROCEDURE p2()
+  SELECT 2;
+
+CREATE DEFINER=a@b FUNCTION f2() RETURNS INT
+  RETURN 2;
+
+# - try to create with explicit definer with empty host;
+
+CREATE DEFINER=a@'' TRIGGER ti_bu BEFORE UPDATE ON t1
+  FOR EACH ROW
+    SET @c = 1;
+
+CREATE DEFINER=a@'' VIEW v3 AS SELECT * FROM t1;
+
+CREATE DEFINER=a@'' PROCEDURE p3()
+  SELECT 3;
+
+CREATE DEFINER=a@'' FUNCTION f3() RETURNS INT
+  RETURN 3;
+
+# - check that empty host name is treated correctly;
+
+SHOW CREATE VIEW v3;
+
+SHOW CREATE PROCEDURE p3;
+
+SHOW CREATE FUNCTION f3;
+
 # Cleanup.
 
 DROP TRIGGER t1_bi;
 DROP TRIGGER ti_ai;
+DROP TRIGGER ti_bu;
 
 DROP VIEW v1;
 DROP VIEW v2;
+DROP VIEW v3;
 
 DROP TABLE t1;
+
+DROP PROCEDURE p1;
+DROP PROCEDURE p2;
+DROP PROCEDURE p3;
+
+DROP FUNCTION f1;
+DROP FUNCTION f2;
+DROP FUNCTION f3;
diff --git a/mysql-test/t/sp.test b/mysql-test/t/sp.test
index 0fbf17761b3..b025b2969b9 100644
--- a/mysql-test/t/sp.test
+++ b/mysql-test/t/sp.test
@@ -5635,6 +5635,22 @@ call bug16887()|
 drop table t3|
 drop procedure bug16887|
 
+#
+# Bug#13575 SP funcs in select with distinct/group and order by can
+#           produce bad data
+#
+create table t3 (f1 int, f2 varchar(3), primary key(f1)) engine=innodb|
+insert into t3 values (1,'aaa'),(2,'bbb'),(3,'ccc')|
+CREATE FUNCTION bug13575 ( p1 integer ) 
+returns varchar(3) 
+BEGIN 
+DECLARE v1 VARCHAR(10) DEFAULT null;
+SELECT f2 INTO v1 FROM t3 WHERE f1 = p1; 
+RETURN v1;
+END|
+select distinct f1, bug13575(f1) from t3 order by f1|
+drop function bug13575;
+drop table t3|
 
 #
 # BUG#NNNN: New bug synopsis
diff --git a/mysql-test/t/view_grant.test b/mysql-test/t/view_grant.test
index 504c4892808..8335c1de20a 100644
--- a/mysql-test/t/view_grant.test
+++ b/mysql-test/t/view_grant.test
@@ -718,5 +718,3 @@ show create view v1;
 show create view v2;
 drop view v1;
 drop view v2;
-
-
diff --git a/sql/item_func.h b/sql/item_func.h
index d8fa45fb9c0..ccbbbab1df4 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -1421,9 +1421,21 @@ public:
 
   String *val_str(String *str)
   {
+    String buf;
+    char buff[20];
+    buf.set(buff, 20, str->charset());
+    buf.length(0);
     if (execute(&result_field))
       return NULL;
-    return result_field->val_str(str);
+    /*
+      result_field will set buf pointing to internal buffer
+      of the resul_field. Due to this it will change any time
+      when SP is executed. In order to prevent occasional
+      corruption of returned value, we make here a copy.
+    */
+    result_field->val_str(&buf);
+    str->copy(buf);
+    return str;
   }
 
   virtual bool change_context_processor(byte *cntx)
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 43b7c494246..9310b65e44a 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -766,6 +766,18 @@ static const char *require_quotes(const char *name, uint name_length)
 }
 
 
+/*
+  Quote the given identifier if needed and append it to the target string.
+  If the given identifier is empty, it will be quoted.
+
+  SYNOPSIS
+  append_identifier()
+  thd                   thread handler
+  packet                target string
+  name                  the identifier to be appended
+  name_length           length of the appending identifier
+*/
+
 void
 append_identifier(THD *thd, String *packet, const char *name, uint length)
 {
@@ -819,8 +831,11 @@ append_identifier(THD *thd, String *packet, const char *name, uint length)
     length	length of name
 
   IMPLEMENTATION
-    If name is a keyword or includes a special character, then force
-    quoting.
+    Force quoting in the following cases:
+      - name is empty (for one, it is possible when we use this function for
+        quoting user and host names for DEFINER clause);
+      - name is a keyword;
+      - name includes a special character;
     Otherwise identifier is quoted only if the option OPTION_QUOTE_SHOW_CREATE
     is set.