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, 6 insertions, 6 deletions

diff --git a/sql/wsrep_thd.cc b/sql/wsrep_thd.cc
index 32b812a9bb2..e8dda53c95f 100644
--- a/sql/wsrep_thd.cc
+++ b/sql/wsrep_thd.cc
@@ -164,22 +164,23 @@ static void wsrep_prepare_bf_thd(THD *thd, struct wsrep_thd_shadow* shadow)
   thd->variables.tx_isolation = ISO_READ_COMMITTED;
   thd->tx_isolation           = ISO_READ_COMMITTED;
 
-  shadow->db            = thd->db;
-  shadow->db_length     = thd->db_length;
+  shadow->db            = thd->db.str;
+  shadow->db_length     = thd->db.length;
   shadow->user_time     = thd->user_time;
   shadow->row_count_func= thd->get_row_count_func();
-  thd->reset_db(NULL, 0);
+  thd->reset_db(&null_clex_str);
 }
 
 static void wsrep_return_from_bf_mode(THD *thd, struct wsrep_thd_shadow* shadow)
 {
+  LEX_CSTRING db= {shadow->db, shadow->db_length };
   thd->variables.option_bits  = shadow->options;
   thd->server_status          = shadow->server_status;
   thd->wsrep_exec_mode        = shadow->wsrep_exec_mode;
   thd->net.vio                = shadow->vio;
   thd->variables.tx_isolation = shadow->tx_isolation;
   thd->user_time              = shadow->user_time;
-  thd->reset_db(shadow->db, shadow->db_length);
+  thd->reset_db(&db);
 
   delete thd->system_thread_info.rpl_sql_info;
   delete thd->wsrep_rgi->rli->mi;
@@ -322,8 +323,7 @@ void wsrep_replay_transaction(THD *thd)
         break;
       default:
         WSREP_ERROR("trx_replay failed for: %d, schema: %s, query: %s",
-                    rcode,
-                    (thd->db ? thd->db : "(null)"),
+                    rcode, thd->get_db(),
                     thd->query() ? thd->query() : "void");
         /* we're now in inconsistent state, must abort */