Fix for BUG#16211: Stored function return type for strings is ignored.

Fix for BUG#16676: Database CHARSET not used for stored procedures

The problem in BUG#16211 is that CHARSET-clause of the return type for
stored functions is just ignored.

The problem in BUG#16676 is that if character set is not explicitly
specified for sp-variable, the server character set is used instead
of the database one.

The fix has two parts:

  - always store CHARSET-clause of the return type along with the
    type definition in mysql.proc.returns column. "Always" means that
    CHARSET-clause is appended even if it has not been explicitly
    specified in CREATE FUNCTION statement (this affects BUG#16211 only).

    Storing CHARSET-clause if it is not specified is essential to avoid
    changing character set if the database character set is altered in
    the future.

    NOTE: this change is not backward compatible with the previous releases.

  - use database default character set if CHARSET-clause is not explicitly
    specified (this affects both BUG#16211 and BUG#16676).

    NOTE: this also breaks backward compatibility.


mysql-test/r/mysqldump.result:
  Updated result file.
mysql-test/r/sp.result:
  Updated result file.
mysql-test/t/sp.test:
  Provided test cases for BUG#16211, BUG#16676.
sql/mysql_priv.h:
  Added two convenient functions for work with databases.
sql/sp.cc:
  1. Add CHARSET-clause to CREATE-statement if it has been explicitly specified.
  2. Polishing -- provided some comments.
sql/sp_head.cc:
  Use database charset as default charset of sp-variable.
sql/sp_head.h:
  Move init_sp_name() out of init_strings().
sql/sql_db.cc:
  Two new functions created:
    - load_db_opt_by_name();
    - check_db_dir_existence();
sql/sql_show.cc:
  Eliminate duplicated code by using
  check_db_dir_existence() and load_db_opt_by_name()
sql/sql_table.cc:
  Eliminate duplicated code by using
  check_db_dir_existence() and load_db_opt_by_name()
sql/sql_yacc.yy:
  Call sp_head::init_sp_name() to initialize stored routine name.

mysql-test/r/mysqldump.result

@@ -2248,7 +2248,7 @@ RETURN a+b */;;
 /*!50003 SET SESSION SQL_MODE=@OLD_SQL_MODE*/;;
 /*!50003 DROP FUNCTION IF EXISTS `bug9056_func2` */;;
 /*!50003 SET SESSION SQL_MODE=""*/;;
-/*!50003 CREATE*/ /*!50020 DEFINER=`root`@`localhost`*/ /*!50003 FUNCTION `bug9056_func2`(f1 char binary) RETURNS char(1)
+/*!50003 CREATE*/ /*!50020 DEFINER=`root`@`localhost`*/ /*!50003 FUNCTION `bug9056_func2`(f1 char binary) RETURNS char(1) CHARSET latin1
 begin
 set f1= concat( 'hello', f1 );
 return f1;

mysql-test/r/sp.result

@@ -5069,4 +5069,157 @@ END |
 SET @a = _latin2"aaaaaaaaaa" |
 CALL bug21013(10) |
 DROP PROCEDURE bug21013 |
+DROP DATABASE IF EXISTS mysqltest1|
+DROP DATABASE IF EXISTS mysqltest2|
+CREATE DATABASE mysqltest1 DEFAULT CHARACTER SET utf8|
+CREATE DATABASE mysqltest2 DEFAULT CHARACTER SET utf8|
+use mysqltest1|
+CREATE FUNCTION bug16211_f1() RETURNS CHAR(10)
+RETURN ""|
+CREATE FUNCTION bug16211_f2() RETURNS CHAR(10) CHARSET koi8r
+RETURN ""|
+CREATE FUNCTION mysqltest2.bug16211_f3() RETURNS CHAR(10)
+RETURN ""|
+CREATE FUNCTION mysqltest2.bug16211_f4() RETURNS CHAR(10) CHARSET koi8r
+RETURN ""|
+SHOW CREATE FUNCTION bug16211_f1|
+Function	sql_mode	Create Function
+bug16211_f1		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f1`() RETURNS char(10) CHARSET utf8
+RETURN ""
+SHOW CREATE FUNCTION bug16211_f2|
+Function	sql_mode	Create Function
+bug16211_f2		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f2`() RETURNS char(10) CHARSET koi8r
+RETURN ""
+SHOW CREATE FUNCTION mysqltest2.bug16211_f3|
+Function	sql_mode	Create Function
+bug16211_f3		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f3`() RETURNS char(10) CHARSET utf8
+RETURN ""
+SHOW CREATE FUNCTION mysqltest2.bug16211_f4|
+Function	sql_mode	Create Function
+bug16211_f4		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f4`() RETURNS char(10) CHARSET koi8r
+RETURN ""
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f1"|
+dtd_identifier
+char(10) CHARSET utf8
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f2"|
+dtd_identifier
+char(10) CHARSET koi8r
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f3"|
+dtd_identifier
+char(10) CHARSET utf8
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f4"|
+dtd_identifier
+char(10) CHARSET koi8r
+SELECT CHARSET(bug16211_f1())|
+CHARSET(bug16211_f1())
+utf8
+SELECT CHARSET(bug16211_f2())|
+CHARSET(bug16211_f2())
+koi8r
+SELECT CHARSET(mysqltest2.bug16211_f3())|
+CHARSET(mysqltest2.bug16211_f3())
+utf8
+SELECT CHARSET(mysqltest2.bug16211_f4())|
+CHARSET(mysqltest2.bug16211_f4())
+koi8r
+ALTER DATABASE mysqltest1 CHARACTER SET cp1251|
+ALTER DATABASE mysqltest2 CHARACTER SET cp1251|
+SHOW CREATE FUNCTION bug16211_f1|
+Function	sql_mode	Create Function
+bug16211_f1		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f1`() RETURNS char(10) CHARSET utf8
+RETURN ""
+SHOW CREATE FUNCTION bug16211_f2|
+Function	sql_mode	Create Function
+bug16211_f2		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f2`() RETURNS char(10) CHARSET koi8r
+RETURN ""
+SHOW CREATE FUNCTION mysqltest2.bug16211_f3|
+Function	sql_mode	Create Function
+bug16211_f3		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f3`() RETURNS char(10) CHARSET utf8
+RETURN ""
+SHOW CREATE FUNCTION mysqltest2.bug16211_f4|
+Function	sql_mode	Create Function
+bug16211_f4		CREATE DEFINER=`root`@`localhost` FUNCTION `bug16211_f4`() RETURNS char(10) CHARSET koi8r
+RETURN ""
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f1"|
+dtd_identifier
+char(10) CHARSET utf8
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f2"|
+dtd_identifier
+char(10) CHARSET koi8r
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f3"|
+dtd_identifier
+char(10) CHARSET utf8
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f4"|
+dtd_identifier
+char(10) CHARSET koi8r
+SELECT CHARSET(bug16211_f1())|
+CHARSET(bug16211_f1())
+utf8
+SELECT CHARSET(bug16211_f2())|
+CHARSET(bug16211_f2())
+koi8r
+SELECT CHARSET(mysqltest2.bug16211_f3())|
+CHARSET(mysqltest2.bug16211_f3())
+utf8
+SELECT CHARSET(mysqltest2.bug16211_f4())|
+CHARSET(mysqltest2.bug16211_f4())
+koi8r
+use test|
+DROP DATABASE mysqltest1|
+DROP DATABASE mysqltest2|
+DROP DATABASE IF EXISTS mysqltest1|
+CREATE DATABASE mysqltest1 DEFAULT CHARACTER SET utf8|
+use mysqltest1|
+CREATE PROCEDURE bug16676_p1(
+IN p1 CHAR(10),
+INOUT p2 CHAR(10),
+OUT p3 CHAR(10))
+BEGIN
+SELECT CHARSET(p1), COLLATION(p1);
+SELECT CHARSET(p2), COLLATION(p2);
+SELECT CHARSET(p3), COLLATION(p3);
+END|
+CREATE PROCEDURE bug16676_p2(
+IN p1 CHAR(10) CHARSET koi8r,
+INOUT p2 CHAR(10) CHARSET cp1251,
+OUT p3 CHAR(10) CHARSET greek)
+BEGIN
+SELECT CHARSET(p1), COLLATION(p1);
+SELECT CHARSET(p2), COLLATION(p2);
+SELECT CHARSET(p3), COLLATION(p3);
+END|
+SET @v2 = 'b'|
+SET @v3 = 'c'|
+CALL bug16676_p1('a', @v2, @v3)|
+CHARSET(p1)	COLLATION(p1)
+utf8	utf8_general_ci
+CHARSET(p2)	COLLATION(p2)
+utf8	utf8_general_ci
+CHARSET(p3)	COLLATION(p3)
+utf8	utf8_general_ci
+CALL bug16676_p2('a', @v2, @v3)|
+CHARSET(p1)	COLLATION(p1)
+koi8r	koi8r_general_ci
+CHARSET(p2)	COLLATION(p2)
+cp1251	cp1251_general_ci
+CHARSET(p3)	COLLATION(p3)
+greek	greek_general_ci
+use test|
+DROP DATABASE mysqltest1|
 drop table t1,t2;

mysql-test/t/sp.test

@@ -5989,6 +5989,164 @@ CALL bug21013(10) |
 DROP PROCEDURE bug21013 |
 
 
+#
+# BUG#16211: Stored function return type for strings is ignored
+#
+
+# Prepare: create database with fixed, pre-defined character set.
+
+--disable_warnings
+DROP DATABASE IF EXISTS mysqltest1|
+DROP DATABASE IF EXISTS mysqltest2|
+--enable_warnings
+
+CREATE DATABASE mysqltest1 DEFAULT CHARACTER SET utf8|
+CREATE DATABASE mysqltest2 DEFAULT CHARACTER SET utf8|
+
+# Test case:
+
+use mysqltest1|
+
+#   - Create two stored functions -- with and without explicit CHARSET-clause
+#     for return value;
+
+CREATE FUNCTION bug16211_f1() RETURNS CHAR(10)
+  RETURN ""|
+
+CREATE FUNCTION bug16211_f2() RETURNS CHAR(10) CHARSET koi8r
+  RETURN ""|
+
+CREATE FUNCTION mysqltest2.bug16211_f3() RETURNS CHAR(10)
+  RETURN ""|
+
+CREATE FUNCTION mysqltest2.bug16211_f4() RETURNS CHAR(10) CHARSET koi8r
+  RETURN ""|
+
+#   - Check that CHARSET-clause is specified for the second function;
+
+SHOW CREATE FUNCTION bug16211_f1|
+SHOW CREATE FUNCTION bug16211_f2|
+
+SHOW CREATE FUNCTION mysqltest2.bug16211_f3|
+SHOW CREATE FUNCTION mysqltest2.bug16211_f4|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f1"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f2"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f3"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f4"|
+
+SELECT CHARSET(bug16211_f1())|
+SELECT CHARSET(bug16211_f2())|
+
+SELECT CHARSET(mysqltest2.bug16211_f3())|
+SELECT CHARSET(mysqltest2.bug16211_f4())|
+
+#   - Alter database character set.
+
+ALTER DATABASE mysqltest1 CHARACTER SET cp1251|
+ALTER DATABASE mysqltest2 CHARACTER SET cp1251|
+
+#   - Check that CHARSET-clause has not changed.
+
+SHOW CREATE FUNCTION bug16211_f1|
+SHOW CREATE FUNCTION bug16211_f2|
+
+SHOW CREATE FUNCTION mysqltest2.bug16211_f3|
+SHOW CREATE FUNCTION mysqltest2.bug16211_f4|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f1"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest1" AND ROUTINE_NAME = "bug16211_f2"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f3"|
+
+SELECT dtd_identifier
+FROM INFORMATION_SCHEMA.ROUTINES
+WHERE ROUTINE_SCHEMA = "mysqltest2" AND ROUTINE_NAME = "bug16211_f4"|
+
+SELECT CHARSET(bug16211_f1())|
+SELECT CHARSET(bug16211_f2())|
+
+SELECT CHARSET(mysqltest2.bug16211_f3())|
+SELECT CHARSET(mysqltest2.bug16211_f4())|
+
+# Cleanup.
+
+use test|
+
+DROP DATABASE mysqltest1|
+DROP DATABASE mysqltest2|
+
+
+#
+# BUG#16676: Database CHARSET not used for stored procedures
+#
+
+# Prepare: create database with fixed, pre-defined character set.
+
+--disable_warnings
+DROP DATABASE IF EXISTS mysqltest1|
+--enable_warnings
+
+CREATE DATABASE mysqltest1 DEFAULT CHARACTER SET utf8|
+
+# Test case:
+
+use mysqltest1|
+
+#   - Create two stored procedures -- with and without explicit CHARSET-clause;
+
+CREATE PROCEDURE bug16676_p1(
+  IN p1 CHAR(10),
+  INOUT p2 CHAR(10),
+  OUT p3 CHAR(10))
+BEGIN
+  SELECT CHARSET(p1), COLLATION(p1);
+  SELECT CHARSET(p2), COLLATION(p2);
+  SELECT CHARSET(p3), COLLATION(p3);
+END|
+
+CREATE PROCEDURE bug16676_p2(
+  IN p1 CHAR(10) CHARSET koi8r,
+  INOUT p2 CHAR(10) CHARSET cp1251,
+  OUT p3 CHAR(10) CHARSET greek)
+BEGIN
+  SELECT CHARSET(p1), COLLATION(p1);
+  SELECT CHARSET(p2), COLLATION(p2);
+  SELECT CHARSET(p3), COLLATION(p3);
+END|
+
+#   - Call procedures.
+
+SET @v2 = 'b'|
+SET @v3 = 'c'|
+
+CALL bug16676_p1('a', @v2, @v3)|
+CALL bug16676_p2('a', @v2, @v3)|
+
+# Cleanup.
+
+use test|
+
+DROP DATABASE mysqltest1|
+
 #
 # BUG#NNNN: New bug synopsis
 #

sql/mysql_priv.h

@@ -1138,7 +1138,10 @@ uint check_word(TYPELIB *lib, const char *val, const char *end,
 bool is_keyword(const char *name, uint len);
 
 #define MY_DB_OPT_FILE "db.opt"
+bool check_db_dir_existence(const char *db_name);
 bool load_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create);
+bool load_db_opt_by_name(THD *thd, const char *db_name,
+                         HA_CREATE_INFO *db_create_info);
 bool my_dbopt_init(void);
 void my_dbopt_cleanup(void);
 void my_dbopt_free(void);

sql/sp.cc

@@ -495,6 +495,13 @@ sp_returns_type(THD *thd, String &result, sp_head *sp)
   table.s = &table.share_not_to_be_used;
   field= sp->create_result_field(0, 0, &table);
   field->sql_type(result);
+
+  if (field->has_charset())
+  {
+    result.append(STRING_WITH_LEN(" CHARSET "));
+    result.append(field->charset()->csname);
+  }
+
   delete field;
 }
 
@@ -974,6 +981,11 @@ sp_find_routine(THD *thd, int type, sp_name *name, sp_cache **cp,
     sp_head *new_sp;
     const char *returns= "";
     char definer[USER_HOST_BUFF_SIZE];
+
+    /*
+      String buffer for RETURNS data type must have system charset;
+      64 -- size of "returns" column of mysql.proc.
+    */
     String retstr(64);
 
     DBUG_PRINT("info", ("found: 0x%lx", (ulong)sp));

sql/sp_head.cc

@@ -470,7 +470,7 @@ sp_head::init(LEX *lex)
   lex->trg_table_fields.empty();
   my_init_dynamic_array(&m_instr, sizeof(sp_instr *), 16, 8);
   m_param_begin= m_param_end= m_body_begin= 0;
-  m_qname.str= m_db.str= m_name.str= m_params.str= 
+  m_qname.str= m_db.str= m_name.str= m_params.str=
     m_body.str= m_defstr.str= 0;
   m_qname.length= m_db.length= m_name.length= m_params.length=
     m_body.length= m_defstr.length= 0;
@@ -478,29 +478,42 @@ sp_head::init(LEX *lex)
   DBUG_VOID_RETURN;
 }
 
+
 void
-sp_head::init_strings(THD *thd, LEX *lex, sp_name *name)
+sp_head::init_sp_name(THD *thd, sp_name *spname)
+{
+  DBUG_ENTER("sp_head::init_sp_name");
+
+  /* Must be initialized in the parser. */
+
+  DBUG_ASSERT(spname && spname->m_db.str && spname->m_db.length);
+
+  /* We have to copy strings to get them into the right memroot. */
+
+  m_db.length= spname->m_db.length;
+  m_db.str= strmake_root(thd->mem_root, spname->m_db.str, spname->m_db.length);
+
+  m_name.length= spname->m_name.length;
+  m_name.str= strmake_root(thd->mem_root, spname->m_name.str,
+                           spname->m_name.length);
+
+  if (spname->m_qname.length == 0)
+    spname->init_qname(thd);
+
+  m_qname.length= spname->m_qname.length;
+  m_qname.str= strmake_root(thd->mem_root, spname->m_qname.str,
+                            m_qname.length);
+}
+
+
+void
+sp_head::init_strings(THD *thd, LEX *lex)
 {
   DBUG_ENTER("sp_head::init_strings");
   uchar *endp;                  /* Used to trim the end */
   /* During parsing, we must use thd->mem_root */
   MEM_ROOT *root= thd->mem_root;
 
-  DBUG_ASSERT(name);
-  /* Must be initialized in the parser */
-  DBUG_ASSERT(name->m_db.str && name->m_db.length);
-
-  /* We have to copy strings to get them into the right memroot */
-  m_db.length= name->m_db.length;
-  m_db.str= strmake_root(root, name->m_db.str, name->m_db.length);
-  m_name.length= name->m_name.length;
-  m_name.str= strmake_root(root, name->m_name.str, name->m_name.length);
-
-  if (name->m_qname.length == 0)
-    name->init_qname(thd);
-  m_qname.length= name->m_qname.length;
-  m_qname.str= strmake_root(root, name->m_qname.str, m_qname.length);
-
   if (m_param_begin && m_param_end)
   {
     m_params.length= m_param_end - m_param_begin;
@@ -1856,14 +1869,18 @@ sp_head::fill_field_definition(THD *thd, LEX *lex,
                                enum enum_field_types field_type,
                                create_field *field_def)
 {
+  HA_CREATE_INFO sp_db_info;
   LEX_STRING cmt = { 0, 0 };
   uint unused1= 0;
   int unused2= 0;
 
+  load_db_opt_by_name(thd, m_db.str, &sp_db_info);
+
   if (field_def->init(thd, (char*) "", field_type, lex->length, lex->dec,
                       lex->type, (Item*) 0, (Item*) 0, &cmt, 0,
                       &lex->interval_list,
-                      (lex->charset ? lex->charset : default_charset_info),
+                      (lex->charset ? lex->charset :
+                                      sp_db_info.default_table_charset),
                       lex->uint_geom_type))
     return TRUE;
 

sql/sp_head.h

@@ -193,9 +193,13 @@ public:
   void
   init(LEX *lex);
 
+  /* Copy sp name from parser. */
+  void
+  init_sp_name(THD *thd, sp_name *spname);
+
   // Initialize strings after parsing header
   void
-  init_strings(THD *thd, LEX *lex, sp_name *name);
+  init_strings(THD *thd, LEX *lex);
 
   int
   create(THD *thd);

sql/sql_db.cc

@@ -295,7 +295,6 @@ static bool write_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create)
   create	Where to store the read options
 
   DESCRIPTION
-    For now, only default-character-set is read.
 
   RETURN VALUES
   0	File found
@@ -383,6 +382,50 @@ err1:
 }
 
 
+/*
+  Retrieve database options by name. Load database options file or fetch from
+  cache.
+
+  SYNOPSIS
+    load_db_opt_by_name()
+    db_name         Database name
+    db_create_info  Where to store the database options
+
+  DESCRIPTION
+    load_db_opt_by_name() is a shortcut for load_db_opt().
+
+  NOTE
+    Although load_db_opt_by_name() (and load_db_opt()) returns status of
+    the operation, it is useless usually and should be ignored. The problem
+    is that there are 1) system databases ("mysql") and 2) virtual
+    databases ("information_schema"), which do not contain options file.
+    So, load_db_opt[_by_name]() returns FALSE for these databases, but this
+    is not an error.
+
+    load_db_opt[_by_name]() clears db_create_info structure in any case, so
+    even on failure it contains valid data. So, common use case is just
+    call load_db_opt[_by_name]() without checking return value and use
+    db_create_info right after that.
+
+  RETURN VALUES (read NOTE!)
+    FALSE   Success
+    TRUE    Failed to retrieve options
+*/
+
+bool load_db_opt_by_name(THD *thd, const char *db_name,
+                         HA_CREATE_INFO *db_create_info)
+{
+  char db_opt_path[FN_REFLEN];
+
+  strxnmov(db_opt_path, sizeof (db_opt_path) - 1, mysql_data_home, "/",
+           db_name, "/", MY_DB_OPT_FILE, NullS);
+
+  unpack_filename(db_opt_path, db_opt_path);
+
+  return load_db_opt(thd, db_opt_path, db_create_info);
+}
+
+
 /*
   Create a database
 
@@ -1126,8 +1169,6 @@ bool mysql_change_db(THD *thd, const char *name, bool no_access_check)
 {
   int path_length, db_length;
   char *db_name;
-  char	path[FN_REFLEN];
-  HA_CREATE_INFO create;
   bool system_db= 0;
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   ulong db_access;
@@ -1196,16 +1237,14 @@ bool mysql_change_db(THD *thd, const char *name, bool no_access_check)
     }
   }
 #endif
-  (void) sprintf(path,"%s/%s", mysql_data_home, db_name);
+
-  path_length= unpack_dirname(path, path);      // Convert if not UNIX
+  if (check_db_dir_existence(db_name))
-  if (path_length && path[path_length-1] == FN_LIBCHAR)
-    path[path_length-1]= '\0';                  // remove ending '\'
-  if (my_access(path,F_OK))
   {
     my_error(ER_BAD_DB_ERROR, MYF(0), db_name);
     my_free(db_name, MYF(0));
     DBUG_RETURN(1);
   }
+
 end:
   x_free(thd->db);
   DBUG_ASSERT(db_name == NULL || db_name[0] != '\0');
@@ -1221,8 +1260,10 @@ end:
   }
   else
   {
-    strmov(path+unpack_dirname(path,path), MY_DB_OPT_FILE);
+    HA_CREATE_INFO create;
-    load_db_opt(thd, path, &create);
+
+    load_db_opt_by_name(thd, db_name, &create);
+
     thd->db_charset= create.default_table_charset ?
       create.default_table_charset :
       thd->variables.collation_server;
@@ -1230,3 +1271,36 @@ end:
   }
   DBUG_RETURN(0);
 }
+
+
+/*
+  Check if there is directory for the database name.
+
+  SYNOPSIS
+    check_db_dir_existence()
+    db_name   database name
+
+  RETURN VALUES
+    FALSE   There is directory for the specified database name.
+    TRUE    The directory does not exist.
+*/
+
+bool check_db_dir_existence(const char *db_name)
+{
+  char db_dir_path[FN_REFLEN];
+  uint db_dir_path_len;
+
+  strxnmov(db_dir_path, sizeof (db_dir_path) - 1, mysql_data_home, "/",
+           db_name, NullS);
+
+  db_dir_path_len= unpack_dirname(db_dir_path, db_dir_path);
+
+  /* Remove trailing '/' or '\' if exists. */
+
+  if (db_dir_path_len && db_dir_path[db_dir_path_len - 1] == FN_LIBCHAR)
+    db_dir_path[db_dir_path_len - 1]= 0;
+
+  /* Check access. */
+
+  return my_access(db_dir_path, F_OK);
+}

sql/sql_show.cc

@@ -439,13 +439,11 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
 {
   Security_context *sctx= thd->security_ctx;
   int length;
-  char path[FN_REFLEN];
   char buff[2048];
   String buffer(buff, sizeof(buff), system_charset_info);
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   uint db_access;
 #endif
-  bool found_libchar;
   HA_CREATE_INFO create;
   uint create_options = create_info ? create_info->options : 0;
   Protocol *protocol=thd->protocol;
@@ -480,23 +478,13 @@ bool mysqld_show_create_db(THD *thd, char *dbname,
   }
   else
   {
-    (void) sprintf(path,"%s/%s",mysql_data_home, dbname);
+    if (check_db_dir_existence(dbname))
-    length=unpack_dirname(path,path);		// Convert if not unix
-    found_libchar= 0;
-    if (length && path[length-1] == FN_LIBCHAR)
-    {
-      found_libchar= 1;
-      path[length-1]=0;				// remove ending '\'
-    }
-    if (access(path,F_OK))
     {
       my_error(ER_BAD_DB_ERROR, MYF(0), dbname);
       DBUG_RETURN(TRUE);
     }
-    if (found_libchar)
+
-      path[length-1]= FN_LIBCHAR;
+    load_db_opt_by_name(thd, dbname, &create);
-    strmov(path+length, MY_DB_OPT_FILE);
-    load_db_opt(thd, path, &create);
   }
   List<Item> field_list;
   field_list.push_back(new Item_empty_string("Database",NAME_LEN));
@@ -2319,8 +2307,11 @@ bool store_schema_shemata(THD* thd, TABLE *table, const char *db_name,
 
 int fill_schema_shemata(THD *thd, TABLE_LIST *tables, COND *cond)
 {
-  char path[FN_REFLEN];
+  /*
-  bool found_libchar;
+    TODO: fill_schema_shemata() is called when new client is connected.
+    Returning error status in this case leads to client hangup.
+  */
+
   INDEX_FIELD_VALUES idx_field_vals;
   List<char> files;
   char *file_name;
@@ -2352,20 +2343,9 @@ int fill_schema_shemata(THD *thd, TABLE_LIST *tables, COND *cond)
 	(grant_option && !check_grant_db(thd, file_name)))
 #endif
     {
-      strxmov(path, mysql_data_home, "/", file_name, NullS);
+      load_db_opt_by_name(thd, file_name, &create);
-      length=unpack_dirname(path,path);		// Convert if not unix
-      found_libchar= 0;
-      if (length && path[length-1] == FN_LIBCHAR)
-      {
-	found_libchar= 1;
-	path[length-1]=0;			// remove ending '\'
-      }
 
-      if (found_libchar)
+      if (store_schema_shemata(thd, table, file_name,
-	path[length-1]= FN_LIBCHAR;
-      strmov(path+length, MY_DB_OPT_FILE);
-      load_db_opt(thd, path, &create);
-      if (store_schema_shemata(thd, table, file_name, 
                                create.default_table_charset))
         DBUG_RETURN(1);
     }

sql/sql_table.cc

@@ -1631,10 +1631,9 @@ bool mysql_create_table(THD *thd,const char *db, const char *table_name,
   if (!create_info->default_table_charset)
   {
     HA_CREATE_INFO db_info;
-    char  path[FN_REFLEN];
+
-    /* Abuse build_table_path() to build the path to the db.opt file */
+    load_db_opt_by_name(thd, db, &db_info);
-    build_table_path(path, sizeof(path), db, MY_DB_OPT_FILE, "");
+
-    load_db_opt(thd, path, &db_info);
     create_info->default_table_charset= db_info.default_table_charset;
   }
 

sql/sql_yacc.yy

@@ -1285,6 +1285,7 @@ create_function_tail:
 	    sp= new sp_head();
 	    sp->reset_thd_mem_root(YYTHD);
 	    sp->init(lex);
+            sp->init_sp_name(YYTHD, lex->spname);
 
 	    sp->m_type= TYPE_ENUM_FUNCTION;
 	    lex->sphead= sp;
@@ -1339,7 +1340,7 @@ create_function_tail:
               YYABORT;
 
 	    lex->sql_command= SQLCOM_CREATE_SPFUNCTION;
-	    sp->init_strings(YYTHD, lex, lex->spname);
+	    sp->init_strings(YYTHD, lex);
             if (!(sp->m_flags & sp_head::HAS_RETURN))
             {
               my_error(ER_SP_NORETURN, MYF(0), sp->m_qname.str);
@@ -9100,6 +9101,7 @@ trigger_tail:
 	    YYABORT;
 	  sp->reset_thd_mem_root(YYTHD);
 	  sp->init(lex);
+          sp->init_sp_name(YYTHD, $3);
 	
 	  lex->stmt_definition_begin= $2;
           lex->ident.str= $7;
@@ -9128,7 +9130,7 @@ trigger_tail:
 	  sp_head *sp= lex->sphead;
 	  
 	  lex->sql_command= SQLCOM_CREATE_TRIGGER;
-	  sp->init_strings(YYTHD, lex, $3);
+	  sp->init_strings(YYTHD, lex);
 	  /* Restore flag if it was cleared above */
 	  if (sp->m_old_cmq)
 	    YYTHD->client_capabilities |= CLIENT_MULTI_QUERIES;
@@ -9176,13 +9178,14 @@ sp_tail:
 	    my_error(ER_SP_NO_RECURSIVE_CREATE, MYF(0), "PROCEDURE");
 	    YYABORT;
 	  }
-	  
+
 	  lex->stmt_definition_begin= $2;
-	  
+
 	  /* Order is important here: new - reset - init */
 	  sp= new sp_head();
 	  sp->reset_thd_mem_root(YYTHD);
 	  sp->init(lex);
+          sp->init_sp_name(YYTHD, $3);
 
 	  sp->m_type= TYPE_ENUM_PROCEDURE;
 	  lex->sphead= sp;
@@ -9220,7 +9223,7 @@ sp_tail:
 	  LEX *lex= Lex;
 	  sp_head *sp= lex->sphead;
 
-	  sp->init_strings(YYTHD, lex, $3);
+	  sp->init_strings(YYTHD, lex);
 	  lex->sql_command= SQLCOM_CREATE_PROCEDURE;
 	  /* Restore flag if it was cleared above */
 	  if (sp->m_old_cmq)