fixed union types merging and table related metadata (BUG#8824)

mysql-test/r/func_group.result:
  new result
mysql-test/r/metadata.result:
  new result
  test of metadata of variables, unions and derived tables
mysql-test/r/union.result:
  new results
  test of union of enum
mysql-test/t/metadata.test:
  test of metadata of variables, unions and derived tables
mysql-test/t/union.test:
  test of union of enum
sql/field.cc:
  Field type merging rules added
  Fixed table name/alias returting for field made from temporary tables
sql/field.h:
  removed unned field type reporting
sql/item.cc:
  fixed bug in NEW_DATE type field creartion
  replaced mechanism of merging types of UNION
sql/item.h:
  replaced mechanism of merging types of UNION
sql/item_func.h:
  new item type to make correct field type detection possible
sql/item_subselect.cc:
  added table name parameter to prepare() to show right table alias for derived tables
sql/sql_derived.cc:
  added table name parameter to prepare() to show right table alias for derived tables
sql/sql_lex.h:
  added table name parameter to prepare() to show right table alias for derived tables
sql/sql_parse.cc:
  made function for enum/set pack length calculation
sql/sql_prepare.cc:
  added table name parameter to prepare() to show right table alias for derived tables
sql/sql_select.cc:
  new temporary table field creation by Item_type_holder
  fixed table alias for temporary table
sql/sql_union.cc:
  added table name parameter to prepare() to show right table alias for derived tables

1 files changed, 6 insertions, 6 deletions

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 5fd59500ace..57479d6f64f 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -29,7 +29,7 @@ int mysql_union(THD *thd, LEX *lex, select_result *result,
 {
   DBUG_ENTER("mysql_union");
   int res= 0;
-  if (!(res= unit->prepare(thd, result, SELECT_NO_UNLOCK)))
+  if (!(res= unit->prepare(thd, result, SELECT_NO_UNLOCK, "")))
     res= unit->exec();
   res|= unit->cleanup();
   DBUG_RETURN(res);
@@ -142,7 +142,8 @@ st_select_lex_unit::init_prepare_fake_select_lex(THD *thd)
 
 
 int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
-				ulong additional_options)
+				ulong additional_options,
+                                const char *tmp_table_alias)
 {
   SELECT_LEX *lex_select_save= thd_arg->lex->current_select;
   SELECT_LEX *sl, *first_select;
@@ -252,7 +253,7 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
       while ((item_tmp= it++))
       {
 	/* Error's in 'new' will be detected after loop */
-	types.push_back(new Item_type_holder(thd_arg, item_tmp, empty_table));
+	types.push_back(new Item_type_holder(thd_arg, item_tmp));
       }
 
       if (thd_arg->is_fatal_error)
@@ -271,8 +272,7 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
       Item *type, *item_tmp;
       while ((type= tp++, item_tmp= it++))
       {
-        if (((Item_type_holder*)type)->join_types(thd_arg, item_tmp,
-                                                  empty_table))
+        if (((Item_type_holder*)type)->join_types(thd_arg, item_tmp))
 	  DBUG_RETURN(-1);
       }
     }
@@ -304,7 +304,7 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
 				  (first_select_in_union()->options |
 				   thd_arg->options |
 				   TMP_TABLE_ALL_COLUMNS),
-				  HA_POS_ERROR, (char*) "")))
+				  HA_POS_ERROR, (char *) tmp_table_alias)))
       goto err;
     table->file->extra(HA_EXTRA_WRITE_CACHE);
     table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);