I'm aware that #24118 breaks some test cases, but I believe those test cases were incorrect. I also flagged this PR as introducing breaking changes in the mailing list, please see https://lists.apache.org/thread/g1jq0vkq0wt28mdnbg63bpw8fpx9ml42
I'd like to better understand the scope of the breakage. Is it limited to internal KoP usage—such as test cases where developers use partitioned-topic format without metadata? Or does it also affect users who might be doing this in practice? In our organization, we also maintain KoP and have updated our test cases accordingly. Personally, I believe that the partitioned topic should have associated metadata. If someone uses the partitioned format without metadata, it feels more like a workaround or an unsupported edge case. I'm open to discussion. If this behavior is something users actually depend on, then we should talk about how to handle it more gracefully. Thanks, Zixuan
