MySQL Bugs: #76171: WL#6661 no longer suppresses timestamps for events in the same second?

Bug #76171	WL#6661 no longer suppresses timestamps for events in the same second?
Submitted:	5 Mar 2015 11:06	Modified:	23 Apr 2015 17:48
Reporter:	Laurynas Biveinis (OCA)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.7.2+	OS:	Any
Assigned to:	Paul DuBois	CPU Architecture:	Any
Tags:	slow log

Description:
I see this change in the code but not in the docs, but maybe I'm just not finding it.

WL #6661 did, for example:

-  if (event_time != last_time)
-  {
-    last_time= event_time;
-
-    tm start;
-    localtime_r(&event_time, &start);

So, previously, slow log events falling in the same second would not get a timestamp, and now they always do. Is this change documented anywhere?

How to repeat:
I have looked at http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-2.html and http://dev.mysql.com/doc/refman/5.7/en/slow-query-log.html

Suggested fix:
Clarify docs

Hello Laurynas,

Thank you for the report.

Thanks,
Umesh

Yes, this is a consequence of the 5.7.2 changes to log line format. All log lines get a timestamp prefix.

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly.

Added to slow-log section:

As of MySQL 5.7.2, all log lines contain a timestamp. Previously, for
lines falling in the same second, only the first contained a
timestamp.