Changed database, tablename and alias to be LEX_CSTRING

This was done in, among other things:
- thd->db and thd->db_length
- TABLE_LIST tablename, db, alias and schema_name
- Audit plugin database name
- lex->db
- All db and table names in Alter_table_ctx
- st_select_lex db

Other things:
- Changed a lot of functions to take const LEX_CSTRING* as argument
  for db, table_name and alias. See init_one_table() as an example.
- Changed some function arguments from LEX_CSTRING to const LEX_CSTRING
- Changed some lists from LEX_STRING to LEX_CSTRING
- threads_mysql.result changed because process list_db wasn't always
  correctly updated
- New append_identifier() function that takes LEX_CSTRING* as arguments
- Added new element tmp_buff to Alter_table_ctx to separate temp name
  handling from temporary space
- Ensure we store the length after my_casedn_str() of table/db names
- Removed not used version of rename_table_in_stat_tables()
- Changed Natural_join_column::table_name and db_name() to never return
  NULL (used for print)
- thd->get_db() now returns db as a printable string (thd->db.str or "")

1 files changed, 15 insertions, 19 deletions

diff --git a/sql/sql_truncate.cc b/sql/sql_truncate.cc
index bd3f1fdc111..2ddb4bc042c 100644
--- a/sql/sql_truncate.cc
+++ b/sql/sql_truncate.cc
@@ -48,7 +48,7 @@ static bool fk_info_append_fields(THD *thd, String *str,
 
   while ((field= it++))
   {
-    res|= append_identifier(thd, str, field->str, field->length);
+    res|= append_identifier(thd, str, field);
     res|= str->append(", ");
   }
 
@@ -80,22 +80,17 @@ static const char *fk_info_str(THD *thd, FOREIGN_KEY_INFO *fk_info)
     `db`.`tbl`, CONSTRAINT `id` FOREIGN KEY (`fk`) REFERENCES `db`.`tbl` (`fk`)
   */
 
-  res|= append_identifier(thd, &str, fk_info->foreign_db->str,
-                          fk_info->foreign_db->length);
+  res|= append_identifier(thd, &str, fk_info->foreign_db);
   res|= str.append(".");
-  res|= append_identifier(thd, &str, fk_info->foreign_table->str,
-                          fk_info->foreign_table->length);
+  res|= append_identifier(thd, &str, fk_info->foreign_table);
   res|= str.append(", CONSTRAINT ");
-  res|= append_identifier(thd, &str, fk_info->foreign_id->str,
-                          fk_info->foreign_id->length);
+  res|= append_identifier(thd, &str, fk_info->foreign_id);
   res|= str.append(" FOREIGN KEY (");
   res|= fk_info_append_fields(thd, &str, &fk_info->foreign_fields);
   res|= str.append(") REFERENCES ");
-  res|= append_identifier(thd, &str, fk_info->referenced_db->str,
-                          fk_info->referenced_db->length);
+  res|= append_identifier(thd, &str, fk_info->referenced_db);
   res|= str.append(".");
-  res|= append_identifier(thd, &str, fk_info->referenced_table->str,
-                          fk_info->referenced_table->length);
+  res|= append_identifier(thd, &str, fk_info->referenced_table);
   res|= str.append(" (");
   res|= fk_info_append_fields(thd, &str, &fk_info->referenced_fields);
   res|= str.append(')');
@@ -303,8 +298,8 @@ bool Sql_cmd_truncate_table::lock_table(THD *thd, TABLE_LIST *table_ref,
   */
   if (thd->locked_tables_mode)
   {
-    if (!(table= find_table_for_mdl_upgrade(thd, table_ref->db,
-                                            table_ref->table_name, FALSE)))
+    if (!(table= find_table_for_mdl_upgrade(thd, table_ref->db.str,
+                                            table_ref->table_name.str, FALSE)))
       DBUG_RETURN(TRUE);
 
     *hton_can_recreate= ha_check_storage_engine_flag(table->s->db_type(),
@@ -322,11 +317,12 @@ bool Sql_cmd_truncate_table::lock_table(THD *thd, TABLE_LIST *table_ref,
                          thd->variables.lock_wait_timeout, 0))
       DBUG_RETURN(TRUE);
 
-    if (!ha_table_exists(thd, table_ref->db, table_ref->table_name,
+    if (!ha_table_exists(thd, &table_ref->db, &table_ref->table_name,
                          &hton, &is_sequence) ||
         hton == view_pseudo_hton)
     {
-      my_error(ER_NO_SUCH_TABLE, MYF(0), table_ref->db, table_ref->table_name);
+      my_error(ER_NO_SUCH_TABLE, MYF(0), table_ref->db.str,
+               table_ref->table_name.str);
       DBUG_RETURN(TRUE);
     }
 
@@ -364,8 +360,8 @@ bool Sql_cmd_truncate_table::lock_table(THD *thd, TABLE_LIST *table_ref,
   else
   {
     /* Table is already locked exclusively. Remove cached instances. */
-    tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table_ref->db,
-                     table_ref->table_name, FALSE);
+    tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table_ref->db.str,
+                     table_ref->table_name.str, FALSE);
   }
 
   DBUG_RETURN(FALSE);
@@ -418,7 +414,7 @@ bool Sql_cmd_truncate_table::truncate_table(THD *thd, TABLE_LIST *table_ref)
     bool hton_can_recreate;
 
     if (WSREP(thd) &&
-        wsrep_to_isolation_begin(thd, table_ref->db, table_ref->table_name, 0))
+        wsrep_to_isolation_begin(thd, table_ref->db.str, table_ref->table_name.str, 0))
         DBUG_RETURN(TRUE);
     if (lock_table(thd, table_ref, &hton_can_recreate))
       DBUG_RETURN(TRUE);
@@ -429,7 +425,7 @@ bool Sql_cmd_truncate_table::truncate_table(THD *thd, TABLE_LIST *table_ref)
         The storage engine can truncate the table by creating an
         empty table with the same structure.
       */
-      error= dd_recreate_table(thd, table_ref->db, table_ref->table_name);
+      error= dd_recreate_table(thd, table_ref->db.str, table_ref->table_name.str);
 
       if (thd->locked_tables_mode && thd->locked_tables_list.reopen_tables(thd))
           thd->locked_tables_list.unlink_all_closed_tables(thd, NULL, 0);