MDEV-5535: Cannot reopen temporary table

mysqld maintains a list of TABLE objects for all temporary
tables created within a session in THD. Here each table is
represented by a TABLE object.

A query referencing a particular temporary table for more
than once, however, failed with ER_CANT_REOPEN_TABLE error
because a TABLE_SHARE was allocate together with the TABLE,
so temporary tables always had only one TABLE per TABLE_SHARE.

This patch lift this restriction by separating TABLE and
TABLE_SHARE objects and storing TABLE_SHAREs for temporary
tables in a list in THD, and TABLEs in a list within their
respective TABLE_SHAREs.

1 files changed, 7 insertions, 2 deletions

diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index 9f63216af88..13ff5a74b0b 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -4078,7 +4078,12 @@ static TABLE *create_table_from_items(THD *thd,
     }
     else
     {
-      if (open_temporary_table(thd, create_table))
+      /*
+        The pointer to the newly created temporary table has been stored in
+        table->create_info.
+      */
+      create_table->table= create_info->table;
+      if (!create_table->table)
       {
         /*
           This shouldn't happen as creation of temporary table should make
@@ -4087,7 +4092,6 @@ static TABLE *create_table_from_items(THD *thd,
         */
         DBUG_ASSERT(0);
       }
-      DBUG_ASSERT(create_table->table == create_info->table);
     }
   }
   else
@@ -4461,6 +4465,7 @@ void select_create::abort_result_set()
   if (table)
   {
     bool tmp_table= table->s->tmp_table;
+
     table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
     table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE);
     table->auto_increment_field_not_null= FALSE;