The order of queues in row lock is changed (not FIFO)

Hi all,

In pgql-general, I reported that the queue order changed in
the following cases. [1]
・Multiple sessions request row locks for the same tuple
・Update occurs for target tuple

I would like to hear the opinion of experts on whether it is a
specification or a bug.
I think row locking is a FIFO specification, using tuple header
and lock managers. Therefore, I think that the above is a bug.

[1]
https://www.postgresql.org/message-id/TYAPR01MB6073506ECCD7B8F51DA807F68A0F9@TYAPR01MB6073.jpnprd01.prod.outlook.com


Regerds.