MySQL Bugs: #118819: Vertical (\G) doesn't work in MySQL 9.4.0

Bug #118819	Vertical (\G) doesn't work in MySQL 9.4.0
Submitted:	13 Aug 5:53	Modified:	13 Aug 13:50
Reporter:	Mark Callaghan	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Command-line Clients	Severity:	S2 (Serious)
Version:	9.4.0	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	regression

Description:
All of these work prior to 9.4.0
mysql -u... -p... -h... -e 'select 1'
mysql -u... -p... -h... -e 'select 1' -E
mysql -u... -p... -h... -e 'select 1\G'
mysql -u... -p... -h... -e 'select 1 \G'

The last two fail in 9.4.0
mysql -u... -p... -h... -e 'select 1\G'
mysql -u... -p... -h... -e 'select 1 \G'

And the error is:
ERROR at line 1: Unknown command '\G'

How to repeat:
Build 9.4.0 from source
Run the SQL listed above

Suggested fix:
Please add an MTR test for this

Hello Mark,

Thank you for the report and feedback.

Sincerely,
Umesh

It's effection of default-value of --commands (false)

https://dev.mysql.com/doc/refman/9.4/en/mysql-command-options.html#option_mysql_commands

Workaround is adding --commands into option like `mysql --commands` .
But I hope the default will be changed true for compatibility.

Whether this change is on purpose or by mistake it is going to break a lot of existing usage.

Someone was kind enough to find the code change for this:
https://www.linkedin.com/feed/update/urn:li:activity:7361269369361809428?commentUrn=urn%3A...

This isn't a bug.  Innovation releases may change things:

https://dev.mysql.com/doc/relnotes/mysql/9.4/en/news-9-4-0.html
"
    Important Change: Added the mysql client --commands option, which enables or disables most mysql client commands.

    This option is disabled by default. To enable it, start the client with --commands or --commands=ON.

    For a complete list of all commands affected by this option, and additional information, see mysql Client Options. (WL #16949)

    References: See also: Bug #36416568, Bug #38066040.
"

1. I noticed that without --commands, running a statement ending with \G returns
"Unknown command '\G'",
whereas other built-in commands like source or help return
"You have an error in your SQL syntax...".
Not sure if this is intentional, or if a more specific error message would make sense here.

2. It seems to only affect non-interactive mode — interactive mode still works for me. Not sure if this is intentional, but the documentation doesn’t mention the scope of this change. It would be great if more details could be included in the release notes and documentation.

Thanks you!