diff options
Diffstat (limited to 'sql/sql_parse.cc')
| -rw-r--r-- | sql/sql_parse.cc | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc index b5864fef19d..55509a31f77 100644 --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -1912,13 +1912,30 @@ bool alloc_query(THD *thd, const char *packet, uint packet_length) pos--; packet_length--; } - /* We must allocate some extra memory for query cache */ + /* We must allocate some extra memory for query cache + + The query buffer layout is: + buffer :== + <statement> The input statement(s) + '\0' Terminating null char (1 byte) + <length> Length of following current database name (size_t) + <db_name> Name of current database + <flags> Flags struct + */ if (! (query= (char*) thd->memdup_w_gap(packet, packet_length, - 1 + thd->db_length + + 1 + sizeof(size_t) + thd->db_length + QUERY_CACHE_FLAGS_SIZE))) return TRUE; query[packet_length]= '\0'; + /* + Space to hold the name of the current database is allocated. We + also store this length, in case current database is changed during + execution. We might need to reallocate the 'query' buffer + */ + size_t *len = (size_t *) (query + packet_length + 1); + *len= thd->db_length; + thd->set_query(query, packet_length); /* Reclaim some memory */ |