WL#2050 - CREATE USER and DROP USER and RENAME USER

Added new commands CREATE USER and RENAME USER.
Changed behaviour of DROP USER.
Changed an error messages for the new commands.


Docs/mysqld_error.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
include/mysqld_error.h:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Changed an error code for more general use.
mysql-test/r/grant.result:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Changed test results.
mysql-test/r/grant2.result:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  New test results.
mysql-test/r/ps_1general.result:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Changed test results.
mysql-test/t/grant.test:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Updated old tests for new behaviour of DROP USER.
  It does now implicitly remove all privileges and
  does not fail when privileges are still in place.
  Fixed a typo, which left an user in the database,
  whereby other tests could be confused.
  Added a DROP USER for another test user.
mysql-test/t/grant2.test:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added new tests for the new features.
sql/share/czech/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/danish/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/dutch/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/english/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/estonian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/french/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/german/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/greek/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/hungarian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/italian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/japanese/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/korean/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/norwegian-ny/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/norwegian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/polish/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/portuguese/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/romanian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/russian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/serbian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/slovak/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/spanish/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/swedish/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/share/ukrainian/errmsg.txt:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Modified an error message for more general use.
sql/sql_acl.cc:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added a destructor for the GRANT_TABLE object to get
  rid of a hash_column in cases where a nonsense row was
  read from the privilege tables. Added code to delete
  such an object when it is not entered into the 
  column_priv_hash due to a nonsense row.
  Added function comments to two unmodified functions.
  Replaced mysql_drop_user() by the implementation of all
  of the functions as specified in the Low Level Design.
sql/sql_acl.h:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added prototypes for new functions.
sql/sql_lex.h:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added new command codes for CREATE USER and
  RENAME USER.
sql/sql_parse.cc:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added case clauses for the new commands CREATE USER
  and RENAME USER.
sql/sql_yacc.yy:
  WL#2050 - CREATE USER and DROP USER and RENAME USER
  Added syntax for the new commands CREATE USER and 
  RENAME USER, reworked DROP USER, introduced a new
  'user_list' and 'rename_list', renamed the old 
  'user_list' to 'grant_list'. The difference is that
  'grant_list' contains 'grant_user' (with optional
  IDENTIFIED BY), while 'user_list' contains 'user'.
  Concentrated privilege initializazions into a new
  section 'clear_privileges'.

1 files changed, 720 insertions, 139 deletions

diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index 9ce00a01e31..d3bfb5b4d1d 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -919,7 +919,7 @@ static void acl_update_user(const char *user, const char *host,
     {
       if (!acl_user->host.hostname && !host[0] ||
 	  acl_user->host.hostname &&
-	  !my_strcasecmp(&my_charset_latin1, host, acl_user->host.hostname))
+	  !my_strcasecmp(system_charset_info, host, acl_user->host.hostname))
       {
 	acl_user->access=privileges;
 	if (mqh->bits & 1)
@@ -998,7 +998,7 @@ static void acl_update_db(const char *user, const char *host, const char *db,
     {
       if (!acl_db->host.hostname && !host[0] ||
 	  acl_db->host.hostname &&
-	  !my_strcasecmp(&my_charset_latin1, host, acl_db->host.hostname))
+	  !my_strcasecmp(system_charset_info, host, acl_db->host.hostname))
       {
 	if (!acl_db->db && !db[0] ||
 	    acl_db->db && !strcmp(db,acl_db->db))
@@ -1141,7 +1141,7 @@ static void init_check_host(void)
   DBUG_ENTER("init_check_host");
   VOID(my_init_dynamic_array(&acl_wild_hosts,sizeof(struct acl_host_and_ip),
 			  acl_users.elements,1));
-  VOID(hash_init(&acl_check_hosts,&my_charset_latin1,acl_users.elements,0,0,
+  VOID(hash_init(&acl_check_hosts,system_charset_info,acl_users.elements,0,0,
 		 (hash_get_key) check_get_key,0,0));
   if (!allow_all_hosts)
   {
@@ -1157,7 +1157,7 @@ static void init_check_host(void)
 	{					// Check if host already exists
 	  acl_host_and_ip *acl=dynamic_element(&acl_wild_hosts,j,
 					       acl_host_and_ip *);
-	  if (!my_strcasecmp(&my_charset_latin1,
+	  if (!my_strcasecmp(system_charset_info,
                              acl_user->host.hostname, acl->hostname))
 	    break;				// already stored
 	}
@@ -1233,7 +1233,7 @@ bool check_change_password(THD *thd, const char *host, const char *user,
   }
   if (!thd->slave_thread &&
       (strcmp(thd->user,user) ||
-       my_strcasecmp(&my_charset_latin1, host, thd->host_or_ip)))
+       my_strcasecmp(system_charset_info, host, thd->host_or_ip)))
   {
     if (check_access(thd, UPDATE_ACL, "mysql",0,1,0))
       return(1);
@@ -1402,7 +1402,7 @@ static bool compare_hostname(const acl_host_and_ip *host, const char *hostname,
     return (tmp & host->ip_mask) == host->ip;
   }
   return (!host->hostname ||
-	  (hostname && !wild_case_compare(&my_charset_latin1,
+	  (hostname && !wild_case_compare(system_charset_info,
                                           hostname,host->hostname)) ||
 	  (ip && !wild_compare(ip,host->hostname,0)));
 }
@@ -1415,7 +1415,7 @@ bool hostname_requires_resolving(const char *hostname)
   int namelen= strlen(hostname);
   int lhlen= strlen(my_localhost);
   if ((namelen == lhlen) &&
-      !my_strnncoll(&my_charset_latin1, (const uchar *)hostname,  namelen,
+      !my_strnncoll(system_charset_info, (const uchar *)hostname,  namelen,
 		    (const uchar *)my_localhost, strlen(my_localhost)))
     return FALSE;
   for (; (cur=*hostname); hostname++)
@@ -1464,8 +1464,8 @@ static bool update_user_table(THD *thd, const char *host, const char *user,
 
   if (!(table=open_ltable(thd,&tables,TL_WRITE)))
     DBUG_RETURN(1); /* purecov: deadcode */
-  table->field[0]->store(host,(uint) strlen(host), &my_charset_latin1);
-  table->field[1]->store(user,(uint) strlen(user), &my_charset_latin1);
+  table->field[0]->store(host,(uint) strlen(host), system_charset_info);
+  table->field[1]->store(user,(uint) strlen(user), system_charset_info);
 
   table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   if (table->file->index_read_idx(table->record[0],0,
@@ -1478,7 +1478,7 @@ static bool update_user_table(THD *thd, const char *host, const char *user,
     DBUG_RETURN(1);				/* purecov: deadcode */
   }
   store_record(table,record[1]);
-  table->field[2]->store(new_password, new_password_len, &my_charset_latin1);
+  table->field[2]->store(new_password, new_password_len, system_charset_info);
   if ((error=table->file->update_row(table->record[1],table->record[0])))
   {
     table->file->print_error(error,MYF(0));	/* purecov: deadcode */
@@ -1546,8 +1546,8 @@ static int replace_user_table(THD *thd, TABLE *table, const LEX_USER &combo,
     password=combo.password.str;
   }
 
-  table->field[0]->store(combo.host.str,combo.host.length, &my_charset_latin1);
-  table->field[1]->store(combo.user.str,combo.user.length, &my_charset_latin1);
+  table->field[0]->store(combo.host.str,combo.host.length, system_charset_info);
+  table->field[1]->store(combo.user.str,combo.user.length, system_charset_info);
   table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   if (table->file->index_read_idx(table->record[0], 0,
 				  (byte*) table->field[0]->ptr,
@@ -1581,11 +1581,11 @@ static int replace_user_table(THD *thd, TABLE *table, const LEX_USER &combo,
     old_row_exists = 0;
     restore_record(table,default_values);       // cp empty row from default_values
     table->field[0]->store(combo.host.str,combo.host.length,
-                           &my_charset_latin1);
+                           system_charset_info);
     table->field[1]->store(combo.user.str,combo.user.length,
-                           &my_charset_latin1);
+                           system_charset_info);
     table->field[2]->store(password, password_len,
-                           &my_charset_latin1);
+                           system_charset_info);
   }
   else
   {
@@ -1596,14 +1596,14 @@ static int replace_user_table(THD *thd, TABLE *table, const LEX_USER &combo,
     DBUG_ASSERT(combo.host.str);
     if (thd->user && combo.password.str &&
         (strcmp(thd->user,combo.user.str) ||
-         my_strcasecmp(&my_charset_latin1,
+         my_strcasecmp(system_charset_info,
                        combo.host.str, thd->host_or_ip)) &&
         check_access(thd, UPDATE_ACL, "mysql",0,1,0))
       goto end;
     old_row_exists = 1;
     store_record(table,record[1]);			// Save copy for update
     if (combo.password.str)			// If password given
-      table->field[2]->store(password, password_len, &my_charset_latin1);
+      table->field[2]->store(password, password_len, system_charset_info);
     else if (!rights && !revoke_grant &&
              lex->ssl_type == SSL_TYPE_NOT_SPECIFIED && !lex->mqh.bits)
     {
@@ -1648,13 +1648,13 @@ static int replace_user_table(THD *thd, TABLE *table, const LEX_USER &combo,
       table->field[27]->store("", 0, &my_charset_latin1);
       if (lex->ssl_cipher)
 	table->field[25]->store(lex->ssl_cipher,
-				strlen(lex->ssl_cipher), &my_charset_latin1);
+				strlen(lex->ssl_cipher), system_charset_info);
       if (lex->x509_issuer)
 	table->field[26]->store(lex->x509_issuer,
-				strlen(lex->x509_issuer), &my_charset_latin1);
+				strlen(lex->x509_issuer), system_charset_info);
       if (lex->x509_subject)
 	table->field[27]->store(lex->x509_subject,
-				strlen(lex->x509_subject), &my_charset_latin1);
+				strlen(lex->x509_subject), system_charset_info);
       break;
     case SSL_TYPE_NOT_SPECIFIED:
       break;
@@ -1756,9 +1756,9 @@ static int replace_db_table(TABLE *table, const char *db,
     DBUG_RETURN(-1);
   }
 
-  table->field[0]->store(combo.host.str,combo.host.length, &my_charset_latin1);
-  table->field[1]->store(db,(uint) strlen(db), &my_charset_latin1);
-  table->field[2]->store(combo.user.str,combo.user.length, &my_charset_latin1);
+  table->field[0]->store(combo.host.str,combo.host.length, system_charset_info);
+  table->field[1]->store(db,(uint) strlen(db), system_charset_info);
+  table->field[2]->store(combo.user.str,combo.user.length, system_charset_info);
   table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   if (table->file->index_read_idx(table->record[0],0,
 				  (byte*) table->field[0]->ptr,
@@ -1772,9 +1772,9 @@ static int replace_db_table(TABLE *table, const char *db,
     }
     old_row_exists = 0;
     restore_record(table,default_values);			// cp empty row from default_values
-    table->field[0]->store(combo.host.str,combo.host.length, &my_charset_latin1);
-    table->field[1]->store(db,(uint) strlen(db), &my_charset_latin1);
-    table->field[2]->store(combo.user.str,combo.user.length, &my_charset_latin1);
+    table->field[0]->store(combo.host.str,combo.host.length, system_charset_info);
+    table->field[1]->store(db,(uint) strlen(db), system_charset_info);
+    table->field[2]->store(combo.user.str,combo.user.length, system_charset_info);
   }
   else
   {
@@ -1862,6 +1862,7 @@ public:
   GRANT_TABLE(const char *h, const char *d,const char *u,
               const char *t, ulong p, ulong c);
   GRANT_TABLE (TABLE *form, TABLE *col_privs);
+  ~GRANT_TABLE();
   bool ok() { return privs != 0 || cols != 0; }
 };
 
@@ -1887,7 +1888,7 @@ GRANT_TABLE::GRANT_TABLE(const char *h, const char *d,const char *u,
   key_length =(uint) strlen(d)+(uint) strlen(u)+(uint) strlen(t)+3;
   hash_key = (char*) alloc_root(&memex,key_length);
   strmov(strmov(strmov(hash_key,user)+1,db)+1,tname);
-  (void) hash_init(&hash_columns,&my_charset_latin1,
+  (void) hash_init(&hash_columns,system_charset_info,
                    0,0,0, (hash_get_key) get_key_column,0,0);
 }
 
@@ -1911,7 +1912,8 @@ GRANT_TABLE::GRANT_TABLE(TABLE *form, TABLE *col_privs)
   if (!db || !tname)
   {
     /* Wrong table row; Ignore it */
-    privs = cols = 0;				/* purecov: inspected */
+    hash_clear(&hash_columns);                  /* allow for destruction */
+    privs= cols= 0;				/* purecov: inspected */
     return;					/* purecov: inspected */
   }
   if (lower_case_table_names)
@@ -1928,16 +1930,16 @@ GRANT_TABLE::GRANT_TABLE(TABLE *form, TABLE *col_privs)
   privs = fix_rights_for_table(privs);
   cols =  fix_rights_for_column(cols);
 
-  (void) hash_init(&hash_columns,&my_charset_latin1,
+  (void) hash_init(&hash_columns,system_charset_info,
                    0,0,0, (hash_get_key) get_key_column,0,0);
   if (cols)
   {
     int key_len;
     col_privs->field[0]->store(orig_host,(uint) strlen(orig_host),
-                               &my_charset_latin1);
-    col_privs->field[1]->store(db,(uint) strlen(db), &my_charset_latin1);
-    col_privs->field[2]->store(user,(uint) strlen(user), &my_charset_latin1);
-    col_privs->field[3]->store(tname,(uint) strlen(tname), &my_charset_latin1);
+                               system_charset_info);
+    col_privs->field[1]->store(db,(uint) strlen(db), system_charset_info);
+    col_privs->field[2]->store(user,(uint) strlen(user), system_charset_info);
+    col_privs->field[3]->store(tname,(uint) strlen(tname), system_charset_info);
     key_len=(col_privs->field[0]->pack_length()+
              col_privs->field[1]->pack_length()+
              col_privs->field[2]->pack_length()+
@@ -1975,6 +1977,12 @@ GRANT_TABLE::GRANT_TABLE(TABLE *form, TABLE *col_privs)
 }
 
 
+GRANT_TABLE::~GRANT_TABLE()
+{
+  hash_free(&hash_columns);
+}
+
+
 static byte* get_grant_table(GRANT_TABLE *buff,uint *length,
 			     my_bool not_used __attribute__((unused)))
 {
@@ -2011,15 +2019,15 @@ static GRANT_TABLE *table_hash_search(const char *host,const char* ip,
     if (exact)
     {
       if ((host &&
-	   !my_strcasecmp(&my_charset_latin1, host, grant_table->host)) ||
+	   !my_strcasecmp(system_charset_info, host, grant_table->host)) ||
 	  (ip && !strcmp(ip,grant_table->host)))
 	return grant_table;
     }
     else
     {
-      if (((host && !wild_case_compare(&my_charset_latin1,
+      if (((host && !wild_case_compare(system_charset_info,
 				       host,grant_table->host)) ||
-	   (ip && !wild_case_compare(&my_charset_latin1,
+	   (ip && !wild_case_compare(system_charset_info,
 				     ip,grant_table->host))) &&
           (!found || found->sort < grant_table->sort))
 	found=grant_table;					// Host ok
@@ -2048,10 +2056,10 @@ static int replace_column_table(GRANT_TABLE *g_t,
   byte key[MAX_KEY_LENGTH];
   DBUG_ENTER("replace_column_table");
 
-  table->field[0]->store(combo.host.str,combo.host.length, &my_charset_latin1);
-  table->field[1]->store(db,(uint) strlen(db), &my_charset_latin1);
-  table->field[2]->store(combo.user.str,combo.user.length, &my_charset_latin1);
-  table->field[3]->store(table_name,(uint) strlen(table_name), &my_charset_latin1);
+  table->field[0]->store(combo.host.str,combo.host.length, system_charset_info);
+  table->field[1]->store(db,(uint) strlen(db), system_charset_info);
+  table->field[2]->store(combo.user.str,combo.user.length, system_charset_info);
+  table->field[3]->store(table_name,(uint) strlen(table_name), system_charset_info);
   key_length=(table->field[0]->pack_length()+ table->field[1]->pack_length()+
 	      table->field[2]->pack_length()+ table->field[3]->pack_length());
   key_copy(key,table->record[0],table->key_info,key_length);
@@ -2069,7 +2077,7 @@ static int replace_column_table(GRANT_TABLE *g_t,
     bool old_row_exists=0;
     key_restore(table->record[0],key,table->key_info,key_length);
     table->field[4]->store(xx->column.ptr(),xx->column.length(),
-                           &my_charset_latin1);
+                           system_charset_info);
 
     table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
     if (table->file->index_read(table->record[0],(byte*) table->field[0]->ptr,
@@ -2088,7 +2096,7 @@ static int replace_column_table(GRANT_TABLE *g_t,
       restore_record(table,default_values);		// Get empty record
       key_restore(table->record[0],key,table->key_info,key_length);
       table->field[4]->store(xx->column.ptr(),xx->column.length(),
-                             &my_charset_latin1);
+                             system_charset_info);
     }
     else
     {
@@ -2160,7 +2168,7 @@ static int replace_column_table(GRANT_TABLE *g_t,
       {
 	GRANT_COLUMN *grant_column = NULL;
 	char  colum_name_buf[HOSTNAME_LENGTH+1];
-	String column_name(colum_name_buf,sizeof(colum_name_buf),&my_charset_latin1);
+	String column_name(colum_name_buf,sizeof(colum_name_buf),system_charset_info);
 
 	privileges&= ~rights;
 	table->field[6]->store((longlong)
@@ -2231,10 +2239,10 @@ static int replace_table_table(THD *thd, GRANT_TABLE *grant_table,
   }
 
   restore_record(table,default_values);			// Get empty record
-  table->field[0]->store(combo.host.str,combo.host.length, &my_charset_latin1);
-  table->field[1]->store(db,(uint) strlen(db), &my_charset_latin1);
-  table->field[2]->store(combo.user.str,combo.user.length, &my_charset_latin1);
-  table->field[3]->store(table_name,(uint) strlen(table_name), &my_charset_latin1);
+  table->field[0]->store(combo.host.str,combo.host.length, system_charset_info);
+  table->field[1]->store(db,(uint) strlen(db), system_charset_info);
+  table->field[2]->store(combo.user.str,combo.user.length, system_charset_info);
+  table->field[3]->store(table_name,(uint) strlen(table_name), system_charset_info);
   store_record(table,record[1]);			// store at pos 1
   table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   if (table->file->index_read_idx(table->record[0],0,
@@ -2279,7 +2287,7 @@ static int replace_table_table(THD *thd, GRANT_TABLE *grant_table,
     }
   }
 
-  table->field[4]->store(grantor,(uint) strlen(grantor), &my_charset_latin1);
+  table->field[4]->store(grantor,(uint) strlen(grantor), system_charset_info);
   table->field[6]->store((longlong) store_table_rights);
   table->field[7]->store((longlong) store_col_rights);
   rights=fix_rights_for_table(store_table_rights);
@@ -2694,7 +2702,7 @@ my_bool grant_init(THD *org_thd)
   DBUG_ENTER("grant_init");
 
   grant_option = FALSE;
-  (void) hash_init(&column_priv_hash,&my_charset_latin1,
+  (void) hash_init(&column_priv_hash,system_charset_info,
 		   0,0,0, (hash_get_key) get_grant_table,
 		   (hash_free_key) free_grant_table,0);
   init_sql_alloc(&memex, ACL_ALLOC_BLOCK_SIZE, 0);
@@ -2759,8 +2767,11 @@ my_bool grant_init(THD *org_thd)
       }
     }
 
-    if (mem_check->ok() && my_hash_insert(&column_priv_hash,(byte*) mem_check))
+    if (! mem_check->ok())
+      delete mem_check;
+    else if (my_hash_insert(&column_priv_hash,(byte*) mem_check))
     {
+      delete mem_check;
       grant_option= FALSE;
       goto end_unlock;
     }
@@ -3077,9 +3088,9 @@ bool check_grant_db(THD *thd,const char *db)
 							  idx);
     if (len < grant_table->key_length &&
 	!memcmp(grant_table->hash_key,helping,len) &&
-	(thd->host && !wild_case_compare(&my_charset_latin1,
+	(thd->host && !wild_case_compare(system_charset_info,
                                          thd->host,grant_table->host) ||
-	 (thd->ip && !wild_case_compare(&my_charset_latin1,
+	 (thd->ip && !wild_case_compare(system_charset_info,
                                         thd->ip,grant_table->host))))
     {
       error=0;					// Found match
@@ -3230,7 +3241,7 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
     if (!(host=acl_user->host.hostname))
       host= "";
     if (!strcmp(lex_user->user.str,user) &&
-	!my_strcasecmp(&my_charset_latin1, lex_user->host.str, host))
+	!my_strcasecmp(system_charset_info, lex_user->host.str, host))
       break;
   }
   if (counter == acl_users.elements)
@@ -3284,7 +3295,8 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
     global.append(lex_user->user.str, lex_user->user.length,
 		  system_charset_info);
     global.append ("'@'",3);
-    global.append(lex_user->host.str,lex_user->host.length);
+    global.append(lex_user->host.str,lex_user->host.length,
+		  system_charset_info);
     global.append ('\'');
     if (acl_user->salt_len)
     {
@@ -3318,7 +3330,8 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
 	if (ssl_options++)
 	  global.append(' ');
 	global.append("SUBJECT \'",9);
-	global.append(acl_user->x509_subject,strlen(acl_user->x509_subject));
+	global.append(acl_user->x509_subject,strlen(acl_user->x509_subject),
+                      system_charset_info);
 	global.append('\'');
       }
       if (acl_user->ssl_cipher)
@@ -3326,7 +3339,8 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
 	if (ssl_options++)
 	  global.append(' ');
 	global.append("CIPHER '",8);
-	global.append(acl_user->ssl_cipher,strlen(acl_user->ssl_cipher));
+	global.append(acl_user->ssl_cipher,strlen(acl_user->ssl_cipher),
+                      system_charset_info);
 	global.append('\'');
       }
     }
@@ -3365,7 +3379,7 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
       host= "";
 
     if (!strcmp(lex_user->user.str,user) &&
-	!my_strcasecmp(&my_charset_latin1, lex_user->host.str, host))
+	!my_strcasecmp(system_charset_info, lex_user->host.str, host))
     {
       want_access=acl_db->access;
       if (want_access)
@@ -3399,7 +3413,8 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
 	db.append(lex_user->user.str, lex_user->user.length,
 		  system_charset_info);
 	db.append ("'@'",3);
-	db.append(lex_user->host.str, lex_user->host.length);
+	db.append(lex_user->host.str, lex_user->host.length,
+                  system_charset_info);
 	db.append ('\'');
 	if (want_access & GRANT_ACL)
 	  db.append(" WITH GRANT OPTION",18);
@@ -3425,7 +3440,7 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
       user= "";
 
     if (!strcmp(lex_user->user.str,user) &&
-	!my_strcasecmp(&my_charset_latin1, lex_user->host.str,
+	!my_strcasecmp(system_charset_info, lex_user->host.str,
                        grant_table->orig_host))
     {
       ulong table_access= grant_table->privs;
@@ -3505,7 +3520,8 @@ bool mysql_show_grants(THD *thd,LEX_USER *lex_user)
 	global.append(lex_user->user.str, lex_user->user.length,
 		      system_charset_info);
 	global.append("'@'",3);
-	global.append(lex_user->host.str,lex_user->host.length);
+	global.append(lex_user->host.str,lex_user->host.length,
+		      system_charset_info);
 	global.append('\'');
 	if (table_access & GRANT_ACL)
 	  global.append(" WITH GRANT OPTION",18);
@@ -3565,6 +3581,27 @@ void get_mqh(const char *user, const char *host, USER_CONN *uc)
     bzero((char*) &uc->user_resources, sizeof(uc->user_resources));
 }
 
+/*
+  Open the grant tables.
+
+  SYNOPSIS
+    open_grant_tables()
+    thd                         The current thread.
+    tables (out)                The 4 elements array for the opened tables.
+
+  DESCRIPTION
+    Tables are numbered as follows:
+    0 user
+    1 db
+    2 tables_priv
+    3 columns_priv
+
+  RETURN
+    1           Skip GRANT handling during replication.
+    0           OK.
+    < 0         Error.
+*/
+
 int open_grant_tables(THD *thd, TABLE_LIST *tables)
 {
   DBUG_ENTER("open_grant_tables");
@@ -3640,111 +3677,641 @@ ACL_USER *check_acl_user(LEX_USER *user_name,
 }
 
 
-bool mysql_drop_user(THD *thd, List <LEX_USER> &list)
+/*
+  Modify a privilege table.
+
+  SYNOPSIS
+    modify_grant_table()
+    table                       The table to modify.
+    host_field                  The host name field.
+    user_field                  The user name field.
+    user_to                     The new name for the user if to be renamed,
+                                NULL otherwise.
+
+  DESCRIPTION
+  Update user/host in the current record if user_to is not NULL.
+  Delete the current record if user_to is NULL.
+
+  RETURN
+    0           OK.
+    != 0        Error.
+*/
+
+static int modify_grant_table(TABLE *table, Field *host_field,
+                              Field *user_field, LEX_USER *user_to)
 {
-  uint counter, acl_userd;
-  int result;
-  ACL_USER *acl_user;
-  ACL_DB *acl_db;
-  TABLE_LIST tables[4];
+  int error;
+  DBUG_ENTER("modify_grant_table");
 
-  DBUG_ENTER("mysql_drop_user");
+  if (user_to)
+  {
+    /* rename */
+    store_record(table, record[1]);
+    host_field->store(user_to->host.str, user_to->host.length,
+                      system_charset_info);
+    user_field->store(user_to->user.str, user_to->user.length,
+                      system_charset_info);
+    if ((error= table->file->update_row(table->record[1], table->record[0])))
+      table->file->print_error(error, MYF(0));
+  }
+  else
+  {
+    /* delete */
+    if ((error=table->file->delete_row(table->record[0])))
+      table->file->print_error(error, MYF(0));
+  }
 
-  if ((result= open_grant_tables(thd, tables)))
-    DBUG_RETURN(result != 1);
+  DBUG_RETURN(error);
+}
 
-  rw_wrlock(&LOCK_grant);
-  VOID(pthread_mutex_lock(&acl_cache->lock));
 
-  LEX_USER *user_name;
-  List_iterator <LEX_USER> user_list(list);
-  while ((user_name=user_list++))
+/*
+  Handle a privilege table.
+
+  SYNOPSIS
+    handle_grant_table()
+    tables                      The array with the four open tables.
+    table_no                    The number of the table to handle (0..3).
+    drop                        If user_from is to be dropped.
+    user_from                   The the user to be searched/dropped/renamed.
+    user_to                     The new name for the user if to be renamed,
+                                NULL otherwise.
+
+  DESCRIPTION
+    Scan through all records in a grant table and apply the requested
+    operation. For the "user" table, a single index access is sufficient,
+    since there is an unique index on (host, user).
+    Delete from grant table if drop is true.
+    Update in grant table if drop is false and user_to is not NULL.
+    Search in grant table if drop is false and user_to is NULL.
+    Tables are numbered as follows:
+    0 user
+    1 db
+    2 tables_priv
+    3 columns_priv
+
+  RETURN
+    > 0         At least one record matched.
+    0           OK, but no record matched.
+    < 0         Error.
+*/
+
+static int handle_grant_table(TABLE_LIST *tables, uint table_no, bool drop,
+                              LEX_USER *user_from, LEX_USER *user_to)
+{
+  int result= 0;
+  int error;
+  TABLE *table= tables[table_no].table;
+  Field *host_field= table->field[0];
+  Field *user_field= table->field[table_no ? 2 : 1];
+  char *host_str= user_from->host.str;
+  char *user_str= user_from->user.str;
+  const char *host;
+  const char *user;
+  DBUG_ENTER("handle_grant_table");
+
+  if (! table_no)
   {
-    if (!(acl_user= check_acl_user(user_name, &counter)))
+    /*
+      The 'user' table has an unique index on (host, user).
+      Thus, we can handle everything with a single index access.
+      The host- and user fields are consecutive in the user table records.
+      So we set host- and user fields of table->record[0] and use the
+      pointer to the host field as key.
+      index_read_idx() will replace table->record[0] (its first argument)
+      by the searched record, if it exists.
+    */
+    DBUG_PRINT("info",("read table: '%s'  search: '%s'@'%s'",
+                       table->real_name, user_str, host_str));
+    host_field->store(host_str, user_from->host.length, system_charset_info);
+    user_field->store(user_str, user_from->user.length, system_charset_info);
+    if ((error= table->file->index_read_idx(table->record[0], 0,
+                                            (byte*) host_field->ptr, 0,
+                                            HA_READ_KEY_EXACT)))
     {
-      sql_print_error("DROP USER: Can't drop user: '%s'@'%s'; No such user",
-		      user_name->user.str,
-		      user_name->host.str);
-      result= -1;
-      continue;
+      if (error != HA_ERR_KEY_NOT_FOUND)
+      {
+        table->file->print_error(error, MYF(0));
+        result= -1;
+      }
     }
-    if ((acl_user->access & ~0))
+    else
     {
-      sql_print_error("DROP USER: Can't drop user: '%s'@'%s'; Global privileges exists",
-		      user_name->user.str,
-		      user_name->host.str);
+      /* If requested, delete or update the record. */
+      result= ((drop || user_to) &&
+               modify_grant_table(table, host_field, user_field, user_to)) ?
+        -1 : 1; /* Error or found. */
+    }
+    DBUG_PRINT("info",("read result: %d", result));
+  }
+  else
+  {
+    /*
+      The non-'user' table do not have indexes on (host, user).
+      And their host- and user fields are not consecutive.
+      Thus, we need to do a table scan to find all matching records.
+    */
+    if ((error= table->file->ha_rnd_init(1)))
+    {
+      table->file->print_error(error, MYF(0));
       result= -1;
+    }
+    else
+    {
+#ifdef EXTRA_DEBUG
+      DBUG_PRINT("info",("scan table: '%s'  search: '%s'@'%s'",
+                         table->real_name, user_str, host_str));
+#endif
+      while ((error= table->file->rnd_next(table->record[0])) != 
+             HA_ERR_END_OF_FILE)
+      {
+        if (error)
+        {
+          /* Most probable 'deleted record'. */
+          DBUG_PRINT("info",("scan error: %d", error));
+          continue;
+        }
+        if (! (host= get_field(&mem, host_field)))
+          host= "";
+        if (! (user= get_field(&mem, user_field)))
+          user= "";
+
+#ifdef EXTRA_DEBUG
+        DBUG_PRINT("loop",("scan fields: '%s'@'%s' '%s' '%s' '%s'",
+                           user, host,
+                           get_field(&mem, table->field[1]) /*db*/,
+                           get_field(&mem, table->field[3]) /*table*/,
+                           get_field(&mem, table->field[4]) /*column*/));
+#endif
+        if (strcmp(user_str, user) ||
+            my_strcasecmp(system_charset_info, host_str, host))
+          continue;
+
+        /* If requested, delete or update the record. */
+        result= ((drop || user_to) &&
+                 modify_grant_table(table, host_field, user_field, user_to)) ?
+          -1 : result ? result : 1; /* Error or keep result or found. */
+        /* If search is requested, we do not need to search further. */
+        if (! drop && ! user_to)
+          break ;
+      }
+      (void) table->file->ha_rnd_end();
+      DBUG_PRINT("info",("scan result: %d", result));
+    }
+  }
+
+  DBUG_RETURN(result);
+}
+
+
+/*
+  Handle an in-memory privilege structure.
+
+  SYNOPSIS
+    handle_grant_struct()
+    struct_no                   The number of the structure to handle (0..2).
+    drop                        If user_from is to be dropped.
+    user_from                   The the user to be searched/dropped/renamed.
+    user_to                     The new name for the user if to be renamed,
+                                NULL otherwise.
+
+  DESCRIPTION
+    Scan through all elements in an in-memory grant structure and apply
+    the requested operation.
+    Delete from grant structure if drop is true.
+    Update in grant structure if drop is false and user_to is not NULL.
+    Search in grant structure if drop is false and user_to is NULL.
+    Structures are numbered as follows:
+    0 acl_users
+    1 acl_dbs
+    2 column_priv_hash
+
+  RETURN
+    > 0         At least one element matched.
+    0           OK, but no element matched.
+*/
+
+static int handle_grant_struct(uint struct_no, bool drop,
+                               LEX_USER *user_from, LEX_USER *user_to)
+{
+  int result= 0;
+  uint idx;
+  uint elements;
+  const char *user;
+  const char *host;
+  ACL_USER *acl_user;
+  ACL_DB *acl_db;
+  GRANT_TABLE *grant_table;
+  DBUG_ENTER("handle_grant_struct");
+  LINT_INIT(acl_user);
+  LINT_INIT(acl_db);
+  LINT_INIT(grant_table);
+  DBUG_PRINT("info",("scan struct: %u  search: '%s'@'%s'",
+                     struct_no, user_from->user.str, user_from->host.str));
+
+  /* Get the number of elements in the in-memory structure. */
+  switch (struct_no)
+  {
+  case 0:
+    elements= acl_users.elements;
+    break;
+  case 1:
+    elements= acl_dbs.elements;
+    break;
+  default:
+    elements= column_priv_hash.records;
+  }
+
+#ifdef EXTRA_DEBUG
+    DBUG_PRINT("loop",("scan struct: %u  search    user: '%s'  host: '%s'",
+                       struct_no, user_from->user.str, user_from->host.str));
+#endif
+  /* Loop over all elements. */
+  for (idx= 0; idx < elements; idx++)
+  {
+    /*
+      Get a pointer to the element.
+      Unfortunaltely, the host default differs for the structures.
+    */
+    switch (struct_no)
+    {
+    case 0:
+      acl_user= dynamic_element(&acl_users, idx, ACL_USER*);
+      user= acl_user->user;
+      if (!(host= acl_user->host.hostname))
+        host= "%";
+      break;
+
+    case 1:
+      acl_db= dynamic_element(&acl_dbs, idx, ACL_DB*);
+      user= acl_db->user;
+      host= acl_db->host.hostname;
+      break;
+
+    default:
+      grant_table= (GRANT_TABLE*) hash_element(&column_priv_hash, idx);
+      user= grant_table->user;
+      host= grant_table->host;
+    }
+    if (! user)
+        user= "";
+    if (! host)
+        host= "";
+#ifdef EXTRA_DEBUG
+    DBUG_PRINT("loop",("scan struct: %u  index: %u  user: '%s'  host: '%s'",
+                       struct_no, idx, user, host));
+#endif
+    if (strcmp(user_from->user.str, user) ||
+        my_strcasecmp(system_charset_info, user_from->host.str, host))
       continue;
+
+    result= 1; /* At least one element found. */
+    if ( drop )
+    {
+      switch ( struct_no )
+      {
+      case 0:
+        delete_dynamic_element(&acl_users, idx);
+        break;
+
+      case 1:
+        delete_dynamic_element(&acl_dbs, idx);
+        break;
+
+      default:
+        hash_delete(&column_priv_hash, (byte*) grant_table);
+      }
+      elements--;
+      idx--;
     }
-    acl_userd= counter;
+    else if ( user_to )
+    {
+      switch ( struct_no )
+      {
+      case 0:
+        acl_user->user= strdup_root(&mem, user_to->user.str);
+        acl_user->host.hostname= strdup_root(&mem, user_to->host.str);
+        break;
+
+      case 1:
+        acl_db->user= strdup_root(&mem, user_to->user.str);
+        acl_db->host.hostname= strdup_root(&mem, user_to->host.str);
+        break;
 
-    for (counter= 0 ; counter < acl_dbs.elements ; counter++)
+      default:
+        grant_table->user= strdup_root(&mem, user_to->user.str);
+        grant_table->host= strdup_root(&mem, user_to->host.str);
+      }
+    }
+    else
     {
-      const char *user,*host;
-      acl_db=dynamic_element(&acl_dbs,counter,ACL_DB*);
-      if (!(user= acl_db->user))
-	user= "";
-      if (!(host= acl_db->host.hostname))
-	host= "";
-
-      if (!strcmp(user_name->user.str,user) &&
-	  !my_strcasecmp(system_charset_info, user_name->host.str, host))
-	break;
+      /* If search is requested, we do not need to search further. */
+      break;
+    }
+  }
+#ifdef EXTRA_DEBUG
+  DBUG_PRINT("loop",("scan struct: %u  result %d", struct_no, result));
+#endif
+
+  DBUG_RETURN(result);
+}
+
+
+/*
+  Handle all privilege tables and in-memory privilege structures.
+
+  SYNOPSIS
+    handle_grant_data()
+    tables                      The array with the four open tables.
+    drop                        If user_from is to be dropped.
+    user_from                   The the user to be searched/dropped/renamed.
+    user_to                     The new name for the user if to be renamed,
+                                NULL otherwise.
+
+  DESCRIPTION
+    Go through all grant tables and in-memory grant structures and apply
+    the requested operation.
+    Delete from grant data if drop is true.
+    Update in grant data if drop is false and user_to is not NULL.
+    Search in grant data if drop is false and user_to is NULL.
+
+  RETURN
+    > 0         At least one element matched.
+    0           OK, but no element matched.
+    < 0         Error.
+*/
+
+static int handle_grant_data(TABLE_LIST *tables, bool drop,
+                             LEX_USER *user_from, LEX_USER *user_to)
+{
+  int result= 0;
+  int found;
+  DBUG_ENTER("handle_grant_data");
+
+  /* Handle user table. */
+  if ((found= handle_grant_table(tables, 0, drop, user_from, user_to)) < 0)
+  {
+    /* Handle of table failed, don't touch the in-memory array. */
+    result= -1;
+  }
+  else
+  {
+    /* Handle user array. */
+    if ((handle_grant_struct(0, drop, user_from, user_to) && ! result) || found)
+    {
+      result= 1; /* At least one record/element found. */
+      /* If search is requested, we do not need to search further. */
+      if (! drop && ! user_to)
+        goto end;
     }
-    if (counter != acl_dbs.elements)
+  }
+
+  /* Handle db table. */
+  if ((found= handle_grant_table(tables, 1, drop, user_from, user_to)) < 0)
+  {
+    /* Handle of table failed, don't touch the in-memory array. */
+    result= -1;
+  }
+  else
+  {
+    /* Handle db array. */
+    if (((handle_grant_struct(1, drop, user_from, user_to) && ! result) ||
+         found) && ! result)
     {
-      sql_print_error("DROP USER: Can't drop user: '%s'@'%s'; Database privileges exists",
-		      user_name->user.str,
-		      user_name->host.str);
-      result= -1;
-      continue;
+      result= 1; /* At least one record/element found. */
+      /* If search is requested, we do not need to search further. */
+      if (! drop && ! user_to)
+        goto end;
     }
+  }
 
-    for (counter= 0 ; counter < column_priv_hash.records ; counter++)
+  /* Handle tables table. */
+  if ((found= handle_grant_table(tables, 2, drop, user_from, user_to)) < 0)
+  {
+    /* Handle of table failed, don't touch columns and in-memory array. */
+    result= -1;
+  }
+  else
+  {
+    if (found && ! result)
     {
-      const char *user,*host;
-      GRANT_TABLE *grant_table= (GRANT_TABLE*) hash_element(&column_priv_hash,
-							    counter);
-      if (!(user=grant_table->user))
-	user= "";
-      if (!(host=grant_table->host))
-	host= "";
-
-      if (!strcmp(user_name->user.str,user) &&
-	  !my_strcasecmp(system_charset_info, user_name->host.str, host))
-	break;
+      result= 1; /* At least one record found. */
+      /* If search is requested, we do not need to search further. */
+      if (! drop && ! user_to)
+        goto end;
     }
-    if (counter != column_priv_hash.records)
+
+    /* Handle columns table. */
+    if ((found= handle_grant_table(tables, 3, drop, user_from, user_to)) < 0)
     {
-      sql_print_error("DROP USER: Can't drop user: '%s'@'%s';  Table privileges exists",
-		      user_name->user.str,
-		      user_name->host.str);
+      /* Handle of table failed, don't touch the in-memory array. */
       result= -1;
-      continue;
     }
+    else
+    {
+      /* Handle columns hash. */
+      if (((handle_grant_struct(2, drop, user_from, user_to) && ! result) ||
+           found) && ! result)
+        result= 1; /* At least one record/element found. */
+    }
+  }
+ end:
+  DBUG_RETURN(result);
+}
+
+
+/*
+  Create a list of users.
+
+  SYNOPSIS
+    mysql_create_user()
+    thd                         The current thread.
+    list                        The users to create.
+
+  RETURN
+    FALSE       OK.
+    TRUE        Error.
+*/
+
+bool mysql_create_user(THD *thd, List <LEX_USER> &list)
+{
+  int result;
+  int found;
+  uint failures;
+  ulong sql_mode;
+  LEX_USER *user_name;
+  List_iterator <LEX_USER> user_list(list);
+  TABLE_LIST tables[4];
+  DBUG_ENTER("mysql_create_user");
+
+  /* CREATE USER may be skipped on replication client. */
+  if ((result= open_grant_tables(thd, tables)))
+    DBUG_RETURN(result != 1);
+
+  rw_wrlock(&LOCK_grant);
+  VOID(pthread_mutex_lock(&acl_cache->lock));
+
+  failures= 0;
+  while ((user_name= user_list++))
+  {
+    /*
+      Search all in-memory structures and grant tables
+      for a mention of the new user name.
+    */
+    if ((found= handle_grant_data(tables, 0, user_name, NULL)))
+    {
+      if (found > 0)
+        sql_print_error("CREATE USER: Cannot create user: '%s'@'%s': "
+                        "User exists",
+                        user_name->user.str,
+                        user_name->host.str);
+      failures++;
+      result= TRUE;
+    }
+
+    sql_mode= thd->variables.sql_mode;
+    thd->variables.sql_mode&= ~MODE_NO_AUTO_CREATE_USER;
+    if (replace_user_table(thd, tables[0].table, *user_name, 0, 0, 1))
+    {
+      failures++;
+      result= TRUE;
+    }
+    thd->variables.sql_mode= sql_mode;
+  }
+
+  VOID(pthread_mutex_unlock(&acl_cache->lock));
+  rw_unlock(&LOCK_grant);
+  close_thread_tables(thd);
+  if (result)
+    my_error(ER_HANDLE_USER, MYF(0), "CREATE USER" , failures );
+  DBUG_RETURN(result);
+}
+
+
+/*
+  Drop a list of users and all their privileges.
+
+  SYNOPSIS
+    mysql_drop_user()
+    thd                         The current thread.
+    list                        The users to drop.
+
+  RETURN
+    FALSE       OK.
+    TRUE        Error.
+*/
+
+bool mysql_drop_user(THD *thd, List <LEX_USER> &list)
+{
+  int result;
+  int found;
+  uint failures;
+  LEX_USER *user_name;
+  List_iterator <LEX_USER> user_list(list);
+  TABLE_LIST tables[4];
+  DBUG_ENTER("mysql_drop_user");
+
+  /* CREATE USER may be skipped on replication client. */
+  if ((result= open_grant_tables(thd, tables)))
+    DBUG_RETURN(result != 1);
+
+  rw_wrlock(&LOCK_grant);
+  VOID(pthread_mutex_lock(&acl_cache->lock));
+
+  failures= 0;
+  while ((user_name= user_list++))
+  {
+    if ((found= handle_grant_data(tables, 1, user_name, NULL)) < 0)
+    {
+      failures++;
+      result= TRUE;
+    }
+    else if (! found)
+    {
+      sql_print_error("DROP USER: Cannot drop user '%s'@'%s': "
+                      "No such user",
+                      user_name->user.str,
+                      user_name->host.str);
+      failures++;
+      result= TRUE;
+    }
+  }
+
+  VOID(pthread_mutex_unlock(&acl_cache->lock));
+  rw_unlock(&LOCK_grant);
+  close_thread_tables(thd);
+  if (result)
+    my_error(ER_HANDLE_USER, MYF(0), "DROP USER" , failures );
+  DBUG_RETURN(result);
+}
+
 
-    tables[0].table->field[0]->store(user_name->host.str,(uint)
-				     user_name->host.length,
-				     system_charset_info);
-    tables[0].table->field[1]->store(user_name->user.str,(uint)
-				     user_name->user.length,
-				     system_charset_info);
-    tables[0].table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
-    if (!tables[0].table->file->index_read_idx(tables[0].table->record[0],0,
-					       (byte*) tables[0].table->
-					       field[0]->ptr,
-					       tables[0].table->
-					       key_info[0].key_length,
-					       HA_READ_KEY_EXACT))
+/*
+  Rename a user.
+
+  SYNOPSIS
+    mysql_rename_user()
+    thd                         The current thread.
+    list                        The user name pairs: (from, to).
+
+  RETURN
+    FALSE       OK.
+    TRUE        Error.
+*/
+
+bool mysql_rename_user(THD *thd, List <LEX_USER> &list)
+{
+  int result= 0;
+  int found;
+  uint failures;
+  LEX_USER *user_from;
+  LEX_USER *user_to;
+  List_iterator <LEX_USER> user_list(list);
+  TABLE_LIST tables[4];
+  DBUG_ENTER("mysql_rename_user");
+
+  /* CREATE USER may be skipped on replication client. */
+  if ((result= open_grant_tables(thd, tables)))
+    DBUG_RETURN(result != 1);
+
+  rw_wrlock(&LOCK_grant);
+  VOID(pthread_mutex_lock(&acl_cache->lock));
+
+  failures= 0;
+  while ((user_from= user_list++))
+  {
+    user_to= user_list++;
+    DBUG_ASSERT((user_to)); /* Syntax enforces pairs of users. */
+
+    /*
+      Search all in-memory structures and grant tables
+      for a mention of the new user name.
+    */
+    if ((found= handle_grant_data(tables, 0, user_to, NULL)))
     {
-      int error;
-      if ((error = tables[0].table->file->delete_row(tables[0].table->
-						     record[0])))
+      if (found > 0)
+        sql_print_error("RENAME USER: Cannot rename to: '%s'@'%s': User exists",
+                        user_to->user.str,
+                        user_to->host.str);
+      failures++;
+      result= TRUE;
+    }
+    else
+    {
+      if ((found= handle_grant_data(tables, 0, user_from, user_to)) < 0)
       {
-	tables[0].table->file->print_error(error, MYF(0));
-	DBUG_RETURN(TRUE);
+        failures++;
+        result= TRUE;
+      }
+      else if (! found)
+      {
+        sql_print_error("RENAME USER: Cannot rename user: '%s'@'%s': "
+                        "No such user",
+                        user_from->user.str,
+                        user_from->host.str);
+        failures++;
+        result= TRUE;
       }
-      delete_dynamic_element(&acl_users, acl_userd);
     }
   }
 
@@ -3752,10 +4319,24 @@ bool mysql_drop_user(THD *thd, List <LEX_USER> &list)
   rw_unlock(&LOCK_grant);
   close_thread_tables(thd);
   if (result)
-    my_message(ER_DROP_USER, ER(ER_DROP_USER), MYF(0));
+    my_error(ER_HANDLE_USER, MYF(0), "RENAME USER", failures);
   DBUG_RETURN(result);
 }
 
+/*
+  Revoke all privileges from a list of users.
+
+  SYNOPSIS
+    mysql_revoke_all()
+    thd                         The current thread.
+    list                        The users to revoke all privileges from.
+
+  RETURN
+    > 0         Error. Error message already sent.
+    0           OK.
+    < 0         Error. Error message not yet sent.
+*/
+
 bool mysql_revoke_all(THD *thd,  List <LEX_USER> &list)
 {
   uint counter, revoked;