MEDIUMTEXT out parameter of procedure returns wrong value

[C. Deniz Akyuz]

The MEDIUMTEXT output value of a stored procedure that reads values from an InnoDb table is different from the stored values in the table. When the values are selected from the table directly correct data is obtained. The value returned from the table inside the stored procedure is also correct. However the value is incorrect as read from outside the procedure using the OUT parameter. Using SUBSTR(value, LENGTH(value)) inside the procedure to assign to the output parameter seems to fix this issue.

This bug is detected in version 5.6.28 and not present in version 5.6.21.

Tested version info:

innodb_version 5.6.28-76.1
protocol_version 10
version 5.6.28-76.1-log
version_comment Percona Server (GPL), Release 76.1, Revision 5759e76
version_compile_machine x86_64
version_compile_os debian-linux-gnu

Steps to recreate the bug are in the attached file.

[Kenn Takara (kenn-takara)]

Bug fixed upstream (5.6/5.7)
=======================

Bug #22232332: SAVING TEXT FIELD TO TEXT VARIABLE IN A
PROCEDURE RESULTS IN GARBAGE BYTES

Commit: 863f7cebd79e76f90bd8f1e3e0c1a1de5fe77d07 [863f7ce]
Parents: 3d1306f7b7
Author: Sreeharsha Ramanavarapu <email address hidden>
Date: January 7, 2016 at 3:16:59 PM HST

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-506