Hi, Nikita, On May 05, Nikita Malyavin wrote:

revision-id: 24c653be25a (mariadb-11.0.1-123-g24c653be25a) parent(s): c1cbda5a2c8 author: Nikita Malyavin committer: Nikita Malyavin timestamp: 2023-05-04 20:49:43 +0300 message:

unpack_row: unpack a correct number of fields

diff --git a/sql/rpl_record.cc b/sql/rpl_record.cc index 908d2c39d97..30bd80bdfc7 100644 --- a/sql/rpl_record.cc +++ b/sql/rpl_record.cc @@ -228,24 +228,30 @@ int unpack_row(const rpl_group_info *rgi, TABLE *table, uint const colcnt, const TABLE *conv_table= rpl_data.conv_table; DBUG_PRINT("debug", ("Table data: tabldef: %p, conv_table: %p", tabledef, conv_table)); - + bool is_online_alter= rpl_data.is_online_alter(); DBUG_ASSERT(rgi);

- for (field_ptr= begin_ptr; field_ptr < end_ptr && *field_ptr; ++field_ptr) + for (field_ptr= begin_ptr; field_ptr < end_ptr + /* In Online Alter conv_table can be wider than + original table, but we need to unpack it all. */ + && (*field_ptr || is_online_alter);

I failed to understand this, could you please explain? The comment didn't help much, unfortunately. The test case didn't either.

+ ++field_ptr) { + intptr fidx= field_ptr - begin_ptr;

intptr is a variant of int with sizeof(intptr) == sizeof(void*). it's needed to cast a pointer to int, do some math, cast back. here you need my_ptrdiff_t or ptrdiff_t

/* If there is a conversion table, we pick up the field pointer to the conversion table. If the conversion table or the field pointer is NULL, no conversions are necessary. */ - Field *conv_field= conv_table ? conv_table->field[field_ptr - begin_ptr] : NULL; + Field *conv_field= conv_table ? conv_table->field[fidx] : NULL; Field *const f= conv_field ? conv_field : *field_ptr; +#ifdef DBUG_TRACE + Field *dbg= is_online_alter ? f : *field_ptr; +#endif DBUG_PRINT("debug", ("Conversion %srequired for field '%s' (#%ld)", conv_field ? "" : "not ", - (*field_ptr)->field_name.str, - (long) (field_ptr - begin_ptr))); + dbg->field_name.str, + (long) ()));

eh? you surely meant `(long) fidx` ? how did it even compile?

DBUG_ASSERT(f != NULL);

Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org