[Version: 3.13.1] Upload fails for inline attachments with `@Core.AcceptableMediaTypes` annotation

[TiborAdk]

Describe the bug

Annotating an inline attachment with @Core.AcceptableMediaTypes leads to the file upload to fail.

(local development using cds watch)

To Reproduce
Steps to reproduce the behavior:

1. Create an entity with an inline attachment.

using {cuid} from '@sap/cds/common';
using {Attachment, Attachments} from '@cap-js/attachments';

namespace sample

entity Invoices : cuid {
  documentNumber : String;
  // annotation causes file upload to fail
  attachment     : Attachment;
  // Required trigger UI enhancement for attachments due to a different bug.
  attachments    : Composition of many Attachments;
}

annotate Invoices with @(
  UI.LineItem: [ {Value: attachment_filename}],
  UI.Facets  : [] // Required for plugin to add facets
)

(Note: the attachments composition is only required to add the facet for the inline attachment. see: #470)

2. Expose the entity through a service definition and apply annotation

service AccountinService {
  @odata.draft.enabled
  entity Invoices as projection on my.Invoices;
}
annotate AccounetingServie.Invoices with {
  attachment @Core.AcceptableMediatypes: ['application/pdf']
}

3. Start development preview with cds watch
4. Open Fiori preview for AccountingService.Invoices
5. Create a new entity to open the object page
6. Select a file to upload for the inline attachment
7. The upload fails with an on screen error message "The file upload failed".

Logs:

[odata] - PUT /odata/v4/accountin/Invoices(ID=9f9c3291-eccf-40ed-80ac-e9d9c043c3d4,IsActiveEntity=false)/attachment_content 
[cds] - ❗️Uncaught TypeError: Cannot read properties of undefined (reading 'split')
    at checkMimeTypeMatch (.../sample/node_modules/@cap-js/attachments/lib/helper.js:415:33)
    at validateAttachmentMimeType (.../sample/node_modules/@cap-js/attachments/lib/generic-handlers.js:574:8)
    at ApplicationService.putUpdateInlineAttachments (.../sample/node_modules/@cap-js/attachments/lib/plugin.js:601:14)
    at next (.../sample/node_modules/@sap/cds/lib/srv/srv-dispatch.js:57:36)
    at ApplicationService.handle (.../sample/node_modules/@sap/cds/lib/srv/srv-dispatch.js:60:6)
    at process.processTicksAndRejections (node:internal/process/task_queues:104:5)
    at async ApplicationService.draftHandle [as handle] (.../sample/node_modules/@sap/cds/libx/_runtime/fiori/lean-draft.js:1127:7)
[cds] - ❗️server shutdown ...❗️

Expected behavior

When using @Core.AcceptableMediaTypes with an inline attachment, the upload should not fail.

Screenshots

On screen failure message after submiting a document to upload:

Customer Info
Company: TUM project with SAP.

[github-actions]

👋 Hello @TiborAdk, thank you for submitting this issue. Our team is reviewing your report and will follow up with you as soon as possible.

[eric-pSAP]

Hi @TiborAdk,

I just wanted to follow up and thank you for the bug reports. We're experiencing many delays at the moment, but we will have the fixes out as soon as possible. Thank you for your patience!

[eric-pSAP]

Hi @TiborAdk ,

The fix has been released. Thanks for your help!