Files
mattermost/server
Doug Lauder 5504435231 MM-68705 - Order-tolerant Shared Channel plugin API's for receiving attachments (#36486)
* MM-68705 - Make ReceiveSharedChannelAttachmentSyncMsg order tolerant

  Allow plugin remotes to invoke ReceiveSharedChannelAttachmentSyncMsg
  and ReceiveSharedChannelSyncMsg in either order without losing the
  post/file binding, and make repeat deliveries of the same file id
  idempotent.

  Two localised changes inside ReceiveSharedChannelAttachmentSyncMsg:

  - Idempotency check before CreateUploadSession. If a FileInfo with
    the sender's id already exists for the same channel and creator,
    return it instead of inserting a duplicate (which would violate
    the FileInfo PK and force the caller to retry indefinitely after
    any transient ack failure). A mismatched channel or creator on the
    same id is rejected.

  - Lazy bind to post after UploadData. When the matching post is
    already present (post-then-file ordering), CreatePost will have
    stripped the unmatched file id from Post.FileIds; AttachToPost
    plus Post.Overwrite restore the binding. When the post is not
    yet present (file-then-post ordering), the FileInfo is left
    unbound so the eventual post arrival's CreatePost path binds it.
    The post is fetched first because AttachToPost is a blind UPDATE
    that does not validate post existence, so calling it before the
    post exists would orphan the FileInfo.

  No other paths change. Cluster (non-plugin) shared-channel attachments,
  ReceiveSharedChannelProfileImageSyncMsg, and UI uploads are unaffected.

  New tests in shared_channel_test.go cover both orderings, repeated
  receive success and rejection on channel/creator mismatch, and the
  empty-PostId no-op.
2026-05-08 15:35:52 -04:00
..
2026-04-21 02:33:20 -07:00