diff options
Diffstat (limited to 'sql/protocol.cc')
| -rw-r--r-- | sql/protocol.cc | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/sql/protocol.cc b/sql/protocol.cc index e608420f21a..a99259ffbcf 100644 --- a/sql/protocol.cc +++ b/sql/protocol.cc @@ -576,7 +576,8 @@ bool Protocol::send_fields(List<Item> *list, uint flags) else { /* With conversion */ - uint max_char_len; + ulonglong max_length; + uint32 field_length; int2store(pos, thd_charset->number); /* For TEXT/BLOB columns, field_length describes the maximum data @@ -587,12 +588,22 @@ bool Protocol::send_fields(List<Item> *list, uint flags) char_count * mbmaxlen, where character count is taken from the definition of the column. In other words, the maximum number of characters here is limited by the column definition. + + When one has a LONG TEXT column with a single-byte + character set, and the connection character set is multi-byte, the + client may get fields longer than UINT_MAX32, due to + <character set column> -> <character set connection> conversion. + In that case column max length does not fit into the 4 bytes + reserved for it in the protocol. */ - max_char_len= (field.type >= (int) MYSQL_TYPE_TINY_BLOB && - field.type <= (int) MYSQL_TYPE_BLOB) ? - field.length / item->collation.collation->mbminlen : - field.length / item->collation.collation->mbmaxlen; - int4store(pos+2, max_char_len * thd_charset->mbmaxlen); + max_length= (field.type >= MYSQL_TYPE_TINY_BLOB && + field.type <= MYSQL_TYPE_BLOB) ? + field.length / item->collation.collation->mbminlen : + field.length / item->collation.collation->mbmaxlen; + max_length*= thd_charset->mbmaxlen; + field_length= (max_length > UINT_MAX32) ? + UINT_MAX32 : (uint32) max_length; + int4store(pos + 2, field_length); } pos[6]= field.type; int2store(pos+7,field.flags); |