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, 17 deletions

diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index f9801d2bf36..12f230724fb 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -174,7 +174,7 @@ mysql_handle_single_derived(LEX *lex, TABLE_LIST *derived, uint phases)
   DBUG_ENTER("mysql_handle_single_derived");
   DBUG_PRINT("enter", ("phases: 0x%x  allowed: 0x%x  alias: '%s'",
                        phases, allowed_phases,
-                       (derived->alias ? derived->alias : "<NULL>")));
+                       (derived->alias.str ? derived->alias.str : "<NULL>")));
   if (!lex->derived_tables)
     DBUG_RETURN(FALSE);
 
@@ -365,7 +365,7 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived)
   Query_arena *arena, backup;
   DBUG_ENTER("mysql_derived_merge");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
 
   if (derived->merged)
@@ -514,7 +514,7 @@ bool mysql_derived_merge_for_insert(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
   DBUG_ENTER("mysql_derived_merge_for_insert");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
   DBUG_PRINT("info", ("merged_for_insert: %d  is_materialized_derived: %d  "
                       "is_multitable: %d  single_table_updatable: %d  "
@@ -572,7 +572,7 @@ bool mysql_derived_init(THD *thd, LEX *lex, TABLE_LIST *derived)
   SELECT_LEX_UNIT *unit= derived->get_unit();
   DBUG_ENTER("mysql_derived_init");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
 
   // Skip already prepared views/DT
@@ -647,11 +647,10 @@ bool mysql_derived_init(THD *thd, LEX *lex, TABLE_LIST *derived)
 bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
   SELECT_LEX_UNIT *unit= derived->get_unit();
-  DBUG_ENTER("mysql_derived_prepare");
   bool res= FALSE;
-  DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
-                       unit));
+  DBUG_ENTER("mysql_derived_prepare");
+  DBUG_PRINT("enter", ("unit: %p  table_list: %p  alias: '%s'",
+                       unit, derived, derived->alias.str));
 
   if (!unit)
     DBUG_RETURN(FALSE);
@@ -692,7 +691,7 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
                                   (first_select->options |
                                    thd->variables.option_bits |
                                    TMP_TABLE_ALL_COLUMNS),
-                                  derived->alias, FALSE, FALSE, FALSE, 0);
+                                  &derived->alias, FALSE, FALSE, FALSE, 0);
     thd->create_tmp_table_for_derived= FALSE;
 
     if (!res && !derived->table)
@@ -785,7 +784,7 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
                                                    (first_select->options |
                                                    thd->variables.option_bits |
                                                    TMP_TABLE_ALL_COLUMNS),
-                                                   derived->alias,
+                                                   &derived->alias,
                                                    FALSE, FALSE, FALSE,
                                                    0))
   { 
@@ -810,8 +809,8 @@ exit:
         thd->get_stmt_da()->sql_errno() == ER_SP_DOES_NOT_EXIST))
     {
       thd->clear_error();
-      my_error(ER_VIEW_INVALID, MYF(0), derived->db,
-               derived->table_name);
+      my_error(ER_VIEW_INVALID, MYF(0), derived->db.str,
+               derived->table_name.str);
     }
   }
 
@@ -881,11 +880,10 @@ bool mysql_derived_optimize(THD *thd, LEX *lex, TABLE_LIST *derived)
   SELECT_LEX_UNIT *unit= derived->get_unit();
   SELECT_LEX *first_select= unit->first_select();
   SELECT_LEX *save_current_select= lex->current_select;
-
   bool res= FALSE;
   DBUG_ENTER("mysql_derived_optimize");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
 
   lex->current_select= first_select;
@@ -966,7 +964,7 @@ bool mysql_derived_create(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
   DBUG_ENTER("mysql_derived_create");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
   TABLE *table= derived->table;
   SELECT_LEX_UNIT *unit= derived->get_unit();
@@ -1067,7 +1065,7 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
   bool res= FALSE;
   DBUG_ENTER("mysql_derived_fill");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
 
   if (unit->executed && !unit->uncacheable && !unit->describe &&
@@ -1189,7 +1187,7 @@ bool mysql_derived_reinit(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
   DBUG_ENTER("mysql_derived_reinit");
   DBUG_PRINT("enter", ("Alias: '%s'  Unit: %p",
-                       (derived->alias ? derived->alias : "<NULL>"),
+                       (derived->alias.str ? derived->alias.str : "<NULL>"),
                        derived->get_unit()));
   st_select_lex_unit *unit= derived->get_unit();