Hi, Sergey! On Feb 09, svoj@mariadb.org wrote:

revision-id: 6ff2c0a05155f985484e23bd8611eb95f045907f parent(s): f13939061d468a47985dee0268652a6fe2db7862 committer: Sergey Vojtovich branch nick: 10.1 timestamp: 2015-02-09 16:12:00 +0400 message:

MDEV-5309 - RENAME TABLE does not check for existence of the table's engine

When RENAME TABLE is executed, it apparently does not check whether the engine is available (unlike ALTER TABLE .. RENAME, which does). It means that if the engine in question was not loaded on some reason, the table might become unusable, since the engine won't know about the change.

With this patch RENAME TABLE fails if storage engine is not available. .... diff --git a/sql/sql_table.cc b/sql/sql_table.cc index e9a1ae9..f1096da 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -5172,18 +5172,19 @@ bool mysql_create_table(THD *thd, TABLE_LIST *create_table, error= my_errno; (void) file->ha_create_partitioning_metadata(to, from, CHF_RENAME_FLAG); } - else if (!file || !(error=file->ha_rename_table(from_base, to_base))) + else if (!file) { + error= ER_UNKNOWN_STORAGE_ENGINE; + } + else if (!(error= file->ha_rename_table(from_base, to_base))) + { if (!(flags & NO_FRM_RENAME) && rename_file_ext(from,to,reg_ext)) { error= my_errno; - if (file) - { if (error == ENOENT) error= 0; // this is ok if file->ha_rename_table() succeeded else file->ha_rename_table(to_base, from_base); // Restore old file name - } } } delete file;

May be you'd rather fix it in the caller? Let's state that the first argument of mysql_rename_table() can never be NULL. While mysql_rename_table() is called in many places, the only place where it can actually get a NULL hton is sql_rename.cc, if ha_table_exists() returns hton=NULL. I'd add the check here and simplified mysql_rename_table(). Regards, Sergei