Hi, Alexander, On Jan 22, Alexander Barkov wrote:

revision-id: 33e36944232 (mariadb-10.6.20-19-g33e36944232) parent(s): 25be7da2024 author: Alexander Barkov committer: Alexander Barkov timestamp: 2024-11-14 10:19:24 +0400 message:

MDEV-30111 InnoDB: Failing assertion: update->n_fields == 0 in row_ins_sec_index_entry_by_modify

Also fixes:

MDEV-32190 Index corruption with unique key and nopad collation (without DESC or HASH keys)

The code in strings/strcoll.inl when comparing an empty string to a string like 0x0001050001 did not take into account that the leftmost weight in the latter can be zero, while there are some more weights can follow the zero weight.

Rewriting the code to treat the shorter string as smaller than a longer string.

--- a/strings/strcoll.inl +++ b/strings/strcoll.inl @@ -192,10 +192,10 @@ MY_FUNCTION_NAME(strnncoll)(CHARSET_INFO *cs __attribute__((unused)), >0 >0 Two weights were scanned, check weight difference. */ if (!a_wlen) - return b_wlen ? -b_weight : 0; + return b_wlen ? -1 : 0;

if (!b_wlen) - return b_is_prefix ? 0 : a_weight; + return b_is_prefix ? 0 : +1;

if ((res= (a_weight - b_weight))) return res;

Sorry, I don't understand it. The function returns >0, 0, or <0. It shouldn't matter whether it returns -b_weight or -1, a_weight or +1. Except if the weight can be <= 0 itself. But in that case, if ((res= (a_weight - b_weight))) return res; is rather suspicious too. Regards, Sergei Chief Architect, MariaDB Server and security@mariadb.org