Merge bk-internal.mysql.com:/data0/bk/mysql-5.1-runtime

into  bk-internal.mysql.com:/data0/bk/mysql-5.1-wl3337


mysql-test/r/ps_1general.result:
  Auto merged
sql/sp_head.cc:
  Auto merged
sql/table.cc:
  Auto merged
sql/table.h:
  Auto merged

mysql-test/r/drop.result

@@ -74,3 +74,16 @@ show tables;
 Tables_in_test
 t1
 drop table t1;
+drop database if exists mysqltest;
+drop table if exists t1;
+create table t1 (i int);
+lock tables t1 read;
+create database mysqltest;
+ drop table t1;
+show open tables;
+ drop database mysqltest;
+select 1;
+1
+1
+unlock tables;
+End of 5.0 tests

mysql-test/r/ps_1general.result

@@ -308,17 +308,11 @@ prepare stmt4 from ' show engine bdb logs ';
 execute stmt4;
 prepare stmt4 from ' show grants for user ';
 prepare stmt4 from ' show create table t2 ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show master status ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show master logs ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show slave status ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show warnings limit 20 ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show errors limit 20 ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt4 from ' show storage engines ';
 execute stmt4;
 drop table if exists t5;
@@ -387,10 +381,8 @@ ERROR 42000: You have an error in your SQL syntax; check the manual that corresp
 prepare stmt4 from ' use test ' ;
 ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt3 from ' create database mysqltest ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 create database mysqltest ;
 prepare stmt3 from ' drop database mysqltest ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 drop database mysqltest ;
 prepare stmt3 from ' describe t2 ';
 execute stmt3;
@@ -412,7 +404,6 @@ execute stmt1 ;
 prepare stmt1 from ' optimize table t1 ' ;
 prepare stmt1 from ' analyze table t1 ' ;
 prepare stmt1 from ' checksum table t1 ' ;
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt1 from ' repair table t1 ' ;
 prepare stmt1 from ' restore table t1 from ''data.txt'' ' ;
 ERROR HY000: This command is not supported in the prepared statement protocol yet
@@ -440,11 +431,8 @@ execute stmt5;
 1
 SET sql_mode="";
 prepare stmt1 from ' flush local privileges ' ;
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt1 from ' reset query cache ' ;
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt1 from ' KILL 0 ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 prepare stmt1 from ' explain select a from t1 order by b ';
 execute stmt1;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr

mysql-test/r/ps_grant.result

@@ -78,13 +78,10 @@ ERROR 42000: There is no such grant defined for user 'second_user' on host 'loca
 drop database mysqltest;
 prepare stmt3 from ' grant all on test.t1 to drop_user@localhost
 identified by ''looser'' ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 grant all on test.t1 to drop_user@localhost
 identified by 'looser' ;
 prepare stmt3 from ' revoke all privileges on test.t1 from 
 drop_user@localhost ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 revoke all privileges on test.t1 from drop_user@localhost ;
 prepare stmt3 from ' drop user drop_user@localhost ';
-ERROR HY000: This command is not supported in the prepared statement protocol yet
 drop user drop_user@localhost;

mysql-test/r/sp-dynamic.result

@@ -284,11 +284,11 @@ call p1()|
 select * from t1|
 id	stmt_text	status
 1	select 1	supported
-2	flush tables	not supported
+2	flush tables	supported
 3	handler t1 open as ha	not supported
 4	analyze table t1	supported
 5	check table t1	not supported
-6	checksum table t1	not supported
+6	checksum table t1	supported
 7	check table t1	not supported
 8	optimize table t1	supported
 9	repair table t1	supported

mysql-test/t/drop.test

@@ -81,3 +81,44 @@ show tables;
 drop table t1;
 
 # End of 4.1 tests
+
+
+#
+# Test for bug#21216 "Simultaneous DROP TABLE and SHOW OPEN TABLES causes
+# server to crash". Crash (caused by failed assertion in 5.0 or by null
+# pointer dereference in 5.1) happened when one ran SHOW OPEN TABLES
+# while concurrently doing DROP TABLE (or RENAME TABLE, CREATE TABLE LIKE
+# or any other command that takes name-lock) in other connection.
+# 
+# Also includes test for similar bug#12212 "Crash that happens during
+# removing of database name from cache" reappeared in 5.1 as bug#19403
+# In its case crash happened when one concurrently executed DROP DATABASE
+# and one of name-locking command.
+# 
+--disable_warnings
+drop database if exists mysqltest;
+drop table if exists t1;
+--enable_warnings
+create table t1 (i int);
+lock tables t1 read;
+create database mysqltest;
+connect (addconroot1, localhost, root,,);
+--send drop table t1
+connect (addconroot2, localhost, root,,);
+# Server should not crash in any of the following statements
+--disable_result_log
+show open tables;
+--enable_result_log
+--send drop database mysqltest
+connection default;
+select 1;
+unlock tables;
+connection addconroot1;
+--reap
+connection addconroot2;
+--reap
+disconnect addconroot1;
+disconnect addconroot2;
+connection default;
+
+--echo End of 5.0 tests

mysql-test/t/ps_1general.test

@@ -330,17 +330,11 @@ prepare stmt4 from ' show engine bdb logs ';
 execute stmt4;
 --enable_result_log
 prepare stmt4 from ' show grants for user ';
---error 1295
 prepare stmt4 from ' show create table t2 ';
---error 1295
 prepare stmt4 from ' show master status ';
---error 1295
 prepare stmt4 from ' show master logs ';
---error 1295
 prepare stmt4 from ' show slave status ';
---error 1295
 prepare stmt4 from ' show warnings limit 20 ';
---error 1295
 prepare stmt4 from ' show errors limit 20 ';
 prepare stmt4 from ' show storage engines ';
 # The output depends upon the precise order in which
@@ -427,14 +421,12 @@ prepare stmt1 from ' execute stmt2 ' ;
 prepare stmt1 from ' deallocate prepare never_prepared ' ;
 
 ## switch the database connection
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt4 from ' use test ' ;
 
 ## create/drop database
---error 1295
 prepare stmt3 from ' create database mysqltest ';
 create database mysqltest ;
---error 1295
 prepare stmt3 from ' drop database mysqltest ';
 drop database mysqltest ;
 
@@ -446,12 +438,12 @@ drop table t2 ;
 --error 1146
 execute stmt3;
 ## lock/unlock
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt3 from ' lock tables t1 read ' ;
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt3 from ' unlock tables ' ;
 ## Load/Unload table contents
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt1 from ' load data infile ''data.txt''
 into table t1 fields terminated by ''\t'' ';
 prepare stmt1 from ' select * into outfile ''data.txt'' from t1 ';
@@ -459,13 +451,12 @@ execute stmt1 ;
 ## 
 prepare stmt1 from ' optimize table t1 ' ;
 prepare stmt1 from ' analyze table t1 ' ;
---error 1295
 prepare stmt1 from ' checksum table t1 ' ;
 prepare stmt1 from ' repair table t1 ' ;
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt1 from ' restore table t1 from ''data.txt'' ' ;
 ## handler
---error 1295
+--error ER_UNSUPPORTED_PS
 prepare stmt1 from ' handler t1 open ';
 
 
@@ -491,11 +482,8 @@ SET sql_mode=ansi;
 execute stmt5;
 SET sql_mode="";
 
---error 1295
 prepare stmt1 from ' flush local privileges ' ;
---error 1295
 prepare stmt1 from ' reset query cache ' ;
---error 1295
 prepare stmt1 from ' KILL 0 ';
 
 ## simple explain

mysql-test/t/ps_grant.test

@@ -117,15 +117,12 @@ drop database mysqltest;
 #
 # grant/revoke + drop user
 #
---error 1295
 prepare stmt3 from ' grant all on test.t1 to drop_user@localhost
 identified by ''looser'' ';
 grant all on test.t1 to drop_user@localhost
 identified by 'looser' ;
---error 1295
 prepare stmt3 from ' revoke all privileges on test.t1 from 
 drop_user@localhost ';
 revoke all privileges on test.t1 from drop_user@localhost ;
---error 1295
 prepare stmt3 from ' drop user drop_user@localhost ';
 drop user drop_user@localhost;

sql/lock.cc

@@ -874,6 +874,8 @@ int lock_and_wait_for_table_name(THD *thd, TABLE_LIST *table_list)
 int lock_table_name(THD *thd, TABLE_LIST *table_list, bool check_in_use)
 {
   TABLE *table;
+  TABLE_SHARE *share;
+  char *key_buff;
   char  key[MAX_DBKEY_LENGTH];
   char *db= table_list->db;
   uint  key_length;
@@ -903,17 +905,18 @@ int lock_table_name(THD *thd, TABLE_LIST *table_list, bool check_in_use)
   }
   /*
     Create a table entry with the right key and with an old refresh version
-    Note that we must use my_malloc() here as this is freed by the table
-    cache
+    Note that we must use my_multi_malloc() here as this is freed by the
+    table cache
   */
-  if (!(table= (TABLE*) my_malloc(sizeof(*table)+ sizeof(TABLE_SHARE)+
-                                  key_length, MYF(MY_WME | MY_ZEROFILL))))
+  if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
+                       &table, sizeof(*table),
+                       &share, sizeof(*share),
+                       &key_buff, key_length,
+                       NULL))
     DBUG_RETURN(-1);
-  table->s= (TABLE_SHARE*) (table+1);
-  memcpy((table->s->table_cache_key.str= (char*) (table->s+1)), key,
-         key_length);
-  table->s->table_cache_key.length= key_length;
-  table->s->tmp_table= INTERNAL_TMP_TABLE;  // for intern_close_table
+  table->s= share;
+  share->set_table_cache_key(key_buff, key, key_length);
+  share->tmp_table= INTERNAL_TMP_TABLE;  // for intern_close_table
   table->in_use= thd;
   table->locked_by_name=1;
   table_list->table=table;

sql/sp_head.cc

@@ -161,17 +161,20 @@ sp_get_flags_for_command(LEX *lex)
     }
     /* fallthrough */
   case SQLCOM_ANALYZE:
+  case SQLCOM_BACKUP_TABLE:
   case SQLCOM_OPTIMIZE:
   case SQLCOM_PRELOAD_KEYS:
   case SQLCOM_ASSIGN_TO_KEYCACHE:
   case SQLCOM_CHECKSUM:
   case SQLCOM_CHECK:
   case SQLCOM_HA_READ:
+  case SQLCOM_SHOW_AUTHORS:
   case SQLCOM_SHOW_BINLOGS:
   case SQLCOM_SHOW_BINLOG_EVENTS:
   case SQLCOM_SHOW_CHARSETS:
   case SQLCOM_SHOW_COLLATIONS:
   case SQLCOM_SHOW_COLUMN_TYPES:
+  case SQLCOM_SHOW_CONTRIBUTORS:
   case SQLCOM_SHOW_CREATE:
   case SQLCOM_SHOW_CREATE_DB:
   case SQLCOM_SHOW_CREATE_FUNC:
@@ -180,16 +183,20 @@ sp_get_flags_for_command(LEX *lex)
   case SQLCOM_SHOW_DATABASES:
   case SQLCOM_SHOW_ERRORS:
   case SQLCOM_SHOW_FIELDS:
+  case SQLCOM_SHOW_FUNC_CODE:
   case SQLCOM_SHOW_GRANTS:
   case SQLCOM_SHOW_ENGINE_STATUS:
   case SQLCOM_SHOW_ENGINE_LOGS:
   case SQLCOM_SHOW_ENGINE_MUTEX:
+  case SQLCOM_SHOW_EVENTS:
   case SQLCOM_SHOW_KEYS:
   case SQLCOM_SHOW_MASTER_STAT:
   case SQLCOM_SHOW_NEW_MASTER:
   case SQLCOM_SHOW_OPEN_TABLES:
   case SQLCOM_SHOW_PRIVILEGES:
   case SQLCOM_SHOW_PROCESSLIST:
+  case SQLCOM_SHOW_PROC_CODE:
+  case SQLCOM_SHOW_SCHEDULER_STATUS:
   case SQLCOM_SHOW_SLAVE_HOSTS:
   case SQLCOM_SHOW_SLAVE_STAT:
   case SQLCOM_SHOW_STATUS:
@@ -199,12 +206,7 @@ sp_get_flags_for_command(LEX *lex)
   case SQLCOM_SHOW_TABLES:
   case SQLCOM_SHOW_VARIABLES:
   case SQLCOM_SHOW_WARNS:
-  case SQLCOM_SHOW_PROC_CODE:
-  case SQLCOM_SHOW_FUNC_CODE:
-  case SQLCOM_SHOW_AUTHORS:
-  case SQLCOM_SHOW_CONTRIBUTORS:
   case SQLCOM_REPAIR:
-  case SQLCOM_BACKUP_TABLE:
   case SQLCOM_RESTORE_TABLE:
     flags= sp_head::MULTI_RESULTS;
     break;
@@ -262,6 +264,9 @@ sp_get_flags_for_command(LEX *lex)
   case SQLCOM_CREATE_EVENT:
   case SQLCOM_ALTER_EVENT:
   case SQLCOM_DROP_EVENT:
+  case SQLCOM_FLUSH:
+  case SQLCOM_INSTALL_PLUGIN:
+  case SQLCOM_UNINSTALL_PLUGIN:
     flags= sp_head::HAS_COMMIT_OR_ROLLBACK;
     break;
   default:

sql/sql_base.cc

@@ -634,6 +634,7 @@ TABLE_SHARE *get_cached_table_share(const char *db, const char *table_name)
 static void close_handle_and_leave_table_as_lock(TABLE *table)
 {
   TABLE_SHARE *share, *old_share= table->s;
+  char *key_buff;
   MEM_ROOT *mem_root= &table->mem_root;
   DBUG_ENTER("close_handle_and_leave_table_as_lock");
 
@@ -642,20 +643,14 @@ static void close_handle_and_leave_table_as_lock(TABLE *table)
     This has to be done to ensure that the table share is removed from
     the table defintion cache as soon as the last instance is removed
   */
-  if ((share= (TABLE_SHARE*) alloc_root(mem_root, sizeof(*share))))
+  if (multi_alloc_root(mem_root,
+                       &share, sizeof(*share),
+                       &key_buff, old_share->table_cache_key.length,
+                       NULL))
   {
     bzero((char*) share, sizeof(*share));
-    share->db.str= memdup_root(mem_root, old_share->db.str,
-                               old_share->db.length+1);
-    share->db.length= old_share->db.length;
-    share->table_name.str= memdup_root(mem_root,
-                                       old_share->table_name.str,
-                                       old_share->table_name.length+1);
-    share->table_name.length= old_share->table_name.length;
-    share->table_cache_key.str= memdup_root(mem_root,
-                                            old_share->table_cache_key.str,
-                                            old_share->table_cache_key.length);
-    share->table_cache_key.length= old_share->table_cache_key.length;
+    share->set_table_cache_key(key_buff, old_share->table_cache_key.str,
+                               old_share->table_cache_key.length);
     share->tmp_table= INTERNAL_TMP_TABLE;       // for intern_close_table()
   }
 
@@ -1603,28 +1598,18 @@ bool rename_temporary_table(THD* thd, TABLE *table, const char *db,
 			    const char *table_name)
 {
   char *key;
+  uint key_length;
   TABLE_SHARE *share= table->s;
   TABLE_LIST table_list;
-  uint db_length, table_length;
   DBUG_ENTER("rename_temporary_table");
 
-  if (!(key=(char*) alloc_root(&share->mem_root,
-			       (uint) (db_length= strlen(db))+
-			       (uint) (table_length= strlen(table_name))+6+4)))
+  if (!(key=(char*) alloc_root(&share->mem_root, MAX_DBKEY_LENGTH)))
     DBUG_RETURN(1);				/* purecov: inspected */
 
   table_list.db= (char*) db;
   table_list.table_name= (char*) table_name;
-  share->db.str= share->table_cache_key.str= key;
-  share->db.length= db_length;
-  share->table_cache_key.length= create_table_def_key(thd, key,
-                                                      &table_list, 1);
-  /*
-    Here we use the fact that table_name is stored as the second component
-    in the 'key' (after db_name), where components are separated with \0
-  */
-  share->table_name.str=    key+db_length+1;
-  share->table_name.length= table_length;
+  key_length= create_table_def_key(thd, key, &table_list, 1);
+  share->set_table_cache_key(key, key_length);
   DBUG_RETURN(0);
 }
 
@@ -1749,10 +1734,7 @@ bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
 {
   TABLE *table= table_list->table;
   TABLE_SHARE *share;
-  char *db= table_list->db;
   char *table_name= table_list->table_name;
-  char key[MAX_DBKEY_LENGTH];
-  uint key_length;
   TABLE orig_table;
   DBUG_ENTER("reopen_name_locked_table");
 
@@ -1762,7 +1744,6 @@ bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
     DBUG_RETURN(TRUE);
 
   orig_table= *table;
-  key_length=(uint) (strmov(strmov(key,db)+1,table_name)-key)+1;
 
   if (open_unireg_entry(thd, table, table_list, table_name,
                         table->s->table_cache_key.str,

sql/sql_prepare.cc

@@ -1740,6 +1740,20 @@ static bool check_prepared_statement(Prepared_statement *stmt,
   case SQLCOM_SHOW_ENGINE_MUTEX:
   case SQLCOM_SHOW_CREATE_DB:
   case SQLCOM_SHOW_GRANTS:
+  case SQLCOM_SHOW_BINLOG_EVENTS:
+  case SQLCOM_SHOW_MASTER_STAT:
+  case SQLCOM_SHOW_SLAVE_STAT:
+  case SQLCOM_SHOW_CREATE_PROC:
+  case SQLCOM_SHOW_CREATE_FUNC:
+  case SQLCOM_SHOW_CREATE_EVENT:
+  case SQLCOM_SHOW_CREATE:
+  case SQLCOM_SHOW_PROC_CODE:
+  case SQLCOM_SHOW_FUNC_CODE:
+  case SQLCOM_SHOW_AUTHORS:
+  case SQLCOM_SHOW_CONTRIBUTORS:
+  case SQLCOM_SHOW_WARNS:
+  case SQLCOM_SHOW_ERRORS:
+  case SQLCOM_SHOW_BINLOGS:
   case SQLCOM_DROP_TABLE:
   case SQLCOM_RENAME_TABLE:
   case SQLCOM_ALTER_TABLE:
@@ -1754,6 +1768,25 @@ static bool check_prepared_statement(Prepared_statement *stmt,
   case SQLCOM_REPAIR:
   case SQLCOM_ANALYZE:
   case SQLCOM_OPTIMIZE:
+  case SQLCOM_CHANGE_MASTER:
+  case SQLCOM_RESET:
+  case SQLCOM_FLUSH:
+  case SQLCOM_SLAVE_START:
+  case SQLCOM_SLAVE_STOP:
+  case SQLCOM_INSTALL_PLUGIN:
+  case SQLCOM_UNINSTALL_PLUGIN:
+  case SQLCOM_CREATE_DB:
+  case SQLCOM_DROP_DB:
+  case SQLCOM_RENAME_DB:
+  case SQLCOM_CHECKSUM:
+  case SQLCOM_CREATE_USER:
+  case SQLCOM_RENAME_USER:
+  case SQLCOM_DROP_USER:
+  case SQLCOM_ASSIGN_TO_KEYCACHE:
+  case SQLCOM_PRELOAD_KEYS:
+  case SQLCOM_GRANT:
+  case SQLCOM_REVOKE:
+  case SQLCOM_KILL:
     break;
 
   default:

sql/sql_select.cc

@@ -8645,8 +8645,6 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
   share->primary_key= MAX_KEY;               // Indicate no primary key
   share->keys_for_keyread.init();
   share->keys_in_use.init();
-  /* For easier error reporting */
-  share->table_cache_key= share->db;
 
   /* Calculate which type of fields we will store in the temporary table */
 

sql/table.cc

@@ -93,6 +93,7 @@ TABLE_SHARE *alloc_table_share(TABLE_LIST *table_list, char *key,
 {
   MEM_ROOT mem_root;
   TABLE_SHARE *share;
+  char *key_buff, *path_buff;
   char path[FN_REFLEN];
   uint path_length;
   DBUG_ENTER("alloc_table_share");
@@ -103,22 +104,17 @@ TABLE_SHARE *alloc_table_share(TABLE_LIST *table_list, char *key,
                                     table_list->db,
                                     table_list->table_name, "", 0);
   init_sql_alloc(&mem_root, TABLE_ALLOC_BLOCK_SIZE, 0);
-  if ((share= (TABLE_SHARE*) alloc_root(&mem_root,
-					sizeof(*share) + key_length +
-                                        path_length +1)))
+  if (multi_alloc_root(&mem_root,
+                       &share, sizeof(*share),
+                       &key_buff, key_length,
+                       &path_buff, path_length + 1,
+                       NULL))
   {
     bzero((char*) share, sizeof(*share));
-    share->table_cache_key.str=    (char*) (share+1);
-    share->table_cache_key.length= key_length;
-    memcpy(share->table_cache_key.str, key, key_length);
 
-    /* Use the fact the key is db/0/table_name/0 */
-    share->db.str=            share->table_cache_key.str;
-    share->db.length=         strlen(share->db.str);
-    share->table_name.str=    share->db.str + share->db.length + 1;
-    share->table_name.length= strlen(share->table_name.str);
+    share->set_table_cache_key(key_buff, key, key_length);
 
-    share->path.str= share->table_cache_key.str+ key_length;
+    share->path.str= path_buff;
     share->path.length= path_length;
     strmov(share->path.str, path);
     share->normalized_path.str=    share->path.str;

sql/table.h

@@ -138,7 +138,16 @@ typedef struct st_table_share
   CHARSET_INFO *table_charset;		/* Default charset of string fields */
 
   MY_BITMAP all_set;
-  /* A pair "database_name\0table_name\0", widely used as simply a db name */
+  /*
+    Key which is used for looking-up table in table cache and in the list
+    of thread's temporary tables. Has the form of:
+      "database_name\0table_name\0" + optional part for temporary tables.
+
+    Note that all three 'table_cache_key', 'db' and 'table_name' members
+    must be set (and be non-zero) for tables in table cache. They also
+    should correspond to each other.
+    To ensure this one can use set_table_cache() methods.
+  */
   LEX_STRING table_cache_key;
   LEX_STRING db;                        /* Pointer to db */
   LEX_STRING table_name;                /* Table name (for open) */
@@ -223,6 +232,60 @@ typedef struct st_table_share
   uint part_state_len;
   handlerton *default_part_db_type;
 #endif
+
+
+  /*
+    Set share's table cache key and update its db and table name appropriately.
+
+    SYNOPSIS
+      set_table_cache_key()
+        key_buff    Buffer with already built table cache key to be
+                    referenced from share.
+        key_length  Key length.
+
+    NOTES
+      Since 'key_buff' buffer will be referenced from share it should has same
+      life-time as share itself.
+      This method automatically ensures that TABLE_SHARE::table_name/db have
+      appropriate values by using table cache key as their source.
+  */
+
+  void set_table_cache_key(char *key_buff, uint key_length)
+  {
+    table_cache_key.str= key_buff;
+    table_cache_key.length= key_length;
+    /*
+      Let us use the fact that the key is "db/0/table_name/0" + optional
+      part for temporary tables.
+    */
+    db.str=            table_cache_key.str;
+    db.length=         strlen(db.str);
+    table_name.str=    db.str + db.length + 1;
+    table_name.length= strlen(table_name.str);
+  }
+
+
+  /*
+    Set share's table cache key and update its db and table name appropriately.
+
+    SYNOPSIS
+      set_table_cache_key()
+        key_buff    Buffer to be used as storage for table cache key
+                    (should be at least key_length bytes).
+        key         Value for table cache key.
+        key_length  Key length.
+
+    NOTE
+      Since 'key_buff' buffer will be used as storage for table cache key
+      it should has same life-time as share itself.
+  */
+
+  void set_table_cache_key(char *key_buff, const char *key, uint key_length)
+  {
+    memcpy(key_buff, key, key_length);
+    set_table_cache_key(key_buff, key_length);
+  }
+
 } TABLE_SHARE;