Describe the Bug

When a POST /api/<upload-slug>?select[…]=true request creates a doc on a collection configured with @payloadcms/storage-s3 (or any cloud-storage adapter), and the select query projects mimeType (and/or filename) out of the result doc, the file is silently not uploaded to S3:

• HTTP 201 returned
• doc persisted to Mongo with all sharp-computed metadata (filename, mimeType, filesize, sizes)
• Bucket holds no object at the key
• GET <public-url> → 403 / 404
• Server logs: nothing — no error, no warning

The same request without the select query writes all variants to S3 normally.

Root cause

@payloadcms/plugin-cloud-storage/src/utilities/getIncomingFiles.ts reads filename and mimeType from the data argument (the doc passed through hooks):

if (file && data.filename && data.mimeType) {
  const mainFile = { buffer: file.data, ..., mimeType: data.mimeType }
  files = [mainFile]
  // ...build sizes
}
return files

When the request uses ?select[id]=true&select[filename]=true&select[filesize]=true, the doc flowing through hooks is the select-projected version — data.mimeType is undefined. The condition fails, files = [], the afterChange hook in plugin-cloud-storage does nothing, and adapter.handleUpload is never called.

The file itself is on req.file (set by addDataAndFileToRequest / processMultipart) with the correct mime type the whole time. The hook just refuses to use it because the projected doc is missing the field.

Symptom signature

Side-by-side from the reproduction, same source file, same auth, same endpoint:

=== WITH ?select[id,filename,filesize] (broken) → 201 ===
{ "filename": "bug-with-select-….webp", "filesize": 5000, "id": "…" }
bucket: 0 objects for that key

=== WITHOUT select (control) → 201 ===
{ "filename": "ok-without-select-….webp", "filesize": 5000 }
bucket: 5 objects (original + xs/sm/md/og variants)

Link to the code that reproduces this issue

https://github.com/jhb-dev/payload-s3-client-uploads-rest-silent-skip

Reproduction Steps

1. Clone the reproduction repository and run the development server:

   docker compose up -d       # starts mongo + minio + creates the bucket
   pnpm install
   pnpm dev
   

2. In another terminal, run the reproduction script:

   node scripts/reproduce.mjs
   

   The script registers an admin user, mints an API key, and uploads the same test.webp twice — first with ?select[id]=true&select[filename]=true&select[filesize]=true, then with no select query.

3. Inspect the bucket:

   docker exec repro-minio mc ls local/payload-repro-bucket
   

4. Expected: both uploads land in the bucket (original + size variants).

5. Actual: only the control upload (without select) is in the bucket. The first upload — returned 201 with a created doc — has no objects. The doc points at a filename whose binary never reached storage. GET against media.url returns 403/404. No server-side error logged.

Suggested Fix

getIncomingFiles should fall back to the in-memory file object when data.filename / data.mimeType are missing — those fields are already populated on req.file regardless of what the response doc projection includes:

// packages/plugin-cloud-storage/src/utilities/getIncomingFiles.ts
const effectiveFilename = data.filename ?? file?.name
const effectiveMimeType = data.mimeType ?? file?.mimetype

if (file && effectiveFilename && effectiveMimeType) {
  const mainFile = {
    buffer: file.data,
    clientUploadContext: file.clientUploadContext,
    filename: effectiveFilename,
    filesize: file.size,
    mimeType: effectiveMimeType,
    tempFilePath: file.tempFilePath,
  }
  files = [mainFile]
  // …
}

Verified locally with pnpm patch @payloadcms/plugin-cloud-storage@3.84.1 against the reproduction: the main object now uploads correctly when ?select[…] is used.

Follow-up: the same projection issue affects data.sizes. If sizes isn't in the select, image-size variants are still skipped even after the fix above. A complete fix should fall back to req.payloadUploadSizes for variants when data.sizes is missing.

Which area(s) are affected?

plugin: cloud-storage

Environment Info

Relevant Packages:
  payload: 3.84.1
  next: 16.2.6
  @payloadcms/db-mongodb: 3.84.1
  @payloadcms/graphql: 3.84.1
  @payloadcms/next/utilities: 3.84.1
  @payloadcms/plugin-cloud-storage: 3.84.1
  @payloadcms/richtext-lexical: 3.84.1
  @payloadcms/storage-s3: 3.84.1