[Bug]: Thumbnails are being requested for folders

[filerun]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

HTTP GET requests are being made needlessly to "index.php/core/preview" for retrieving thumbnails for folders.

Steps to reproduce

Browse a synched folder via Windows Explorer. Look for HTTP requests made.

Expected behavior

ThumbnailProvider::GetThumbnail should:

SFGAOF attributes = 0; if (SUCCEEDED(_shellItem->GetAttributes(SFGAO_FOLDER, &attributes)) && (attributes & SFGAO_FOLDER)) { return E_FAIL; }

Which files are affected by this bug

None

Operating system

Windows

Which version of the operating system you are running.

Windows 11

Package

Official Linux AppImage

Nextcloud Server version

Latest

Nextcloud Desktop Client version

Latest

Is this bug present after an update or on a fresh install?

Updated from a minor version (ex. 3.16.1 to 3.16.2)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

Additional info

No response