Bug #107553 ColumnDefinition41 different for same request across MySQL 5.7.28 and 8.0.21

• Submitted: 13 Jun 2022 20:17
• Modified: 14 Jul 2022 9:08
• Reporter: Dorothy Ordogh
• Status: No Feedback
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 8.0.21
• OS: MacOS (12.4)
• Assigned to: MySQL Verification Team
• CPU Architecture: x86

[13 Jun 2022 20:17] Dorothy Ordogh

Description:
The Protocol::ColumnDefinition41 message I am returned after sending a request for the same message is different across MySQL 5.7.28 and 8.0.21. Specifically, the bytes that describe the column length and type are different. 

For the query: “SELECT group_concat(‘1’, ‘2’, ‘3’)”

MySQL 5.7.28: 03 64 65 66 00 00 00 12 66 69 6e 61 67 6c 65 2d 6d 79 73 71 6c 2d 74 65 73 74 00 0c 21 00 ff 03 00 00 fd 00 00 00 00 00

MySQL 8.0.21: 03 64 65 66 00 00 00 12 66 69 6e 61 67 6c 65 2d 6d 79 73 71 6c 2d 74 65 73 74 00 0c 21 00 00 24 00 00 fb 00 00 00 00 00

The row packets are the same though: "03 31 32 33"

How to repeat:
Query “SELECT group_concat(‘1’, ‘2’, ‘3’)” and compare the ColumnDefinition41 response packets between 5.7.28 and 8.0.21

MySQL 5.7.28: 03 64 65 66 00 00 00 12 66 69 6e 61 67 6c 65 2d 6d 79 73 71 6c 2d 74 65 73 74 00 0c 21 00 ff 03 00 00 fd 00 00 00 00 00

MySQL 8.0.21: 03 64 65 66 00 00 00 12 66 69 6e 61 67 6c 65 2d 6d 79 73 71 6c 2d 74 65 73 74 00 0c 21 00 00 24 00 00 fb 00 00 00 00 00

The row packets are the same though: "03 31 32 33"

Note that the column length and type are what are different.

[14 Jun 2022 9:08] MySQL Verification Team

Hi Dorothy,

Before I plunge into testing if this "statement" is correct can you please explain why, if it is correct, you believe this is a bug?

Thanks
Bogdan

[15 Jul 2022 1:00] Bugs System

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".