mc cp with --checksum MD5 doesn't seem to store checksum #5136
Description
This bug report resulted from a conversation with @marktheunissen in slack.
Expected behavior
When using the --checksum MD5 argument with mc cp, the MD5 checksum should be stored with the object and accessible in a mc stat CLI or HeadObject API call.
Actual behavior
The MD5 checksum is not available. The CRC32, CRC32C, and SHA256 checksums are available if specified (but see "Other notes" below)
Steps to reproduce the behavior
~$ ~/minio/mc/RELEASE/2025-02-08T19-14-21Z/mc cp --checksum MD5 tinyfile.crap local9000/test/tinyfile.md5.crap
~$ ~/minio/mc/RELEASE/2025-02-08T19-14-21Z/mc stat local9000/test/tinyfile.md5.crap
Name : tinyfile.md5.crap
Date : 2025-02-12 13:07:32 PST
Size : 8 B
ETag : 1b9554867d35f0d59e4705f6b2712cd1
Type : file
Metadata :
Content-Type: application/octet-stream
mc --version
~$ ~/minio/mc/RELEASE/2025-02-08T19-14-21Z/mc -v
mc version RELEASE.2025-02-08T19-14-21Z (commit-id=bd925c01a1ccab367993f20c251b7bae9d22f8a5)
Runtime: go1.23.6 linux/amd64
Copyright (c) 2015-2025 MinIO, Inc.
License GNU AGPLv3 <https://www.gnu.org/licenses/agpl-3.0.html>
~$ ~/minio/mc/RELEASE/2025-02-08T19-14-21Z/mc admin info local9000
● localhost:9000
Uptime: 1 hour
Version: 2025-02-07T23:21:09Z
*snip*
System information
Just my laptop
Other notes
It seems that if multiple --checksum arguments are supplied on the command line, they're all ignored except for the last one. I would expect either they're all honored or an error is thrown. If you'd like me to make another issue for this LMK