Fix: (Pixelfed) Follow

[pfefferle]

add_to_outbox only supports generic visibilities like for example ACTIVITYPUB_CONTENT_VISIBILITY_PRIVATE or 'ACTIVITYPUB_CONTENT_VISIBILITY_PUBLIC'. For custom audiences, we would have to add the to, cc, ... fields of the Activity. With the former implementation, we were only able to set the audience for the Activity>Object and these were up-merged to the Activity afterwards. In the case of an Accept of a Follow we were forced to update the Follow-Activity. But because the Follow was sent by a remote platform, adding a new field (to for example) would change the scope and could cause problems for remote verification.

With the rewrite to store the full Activity instead of the Object, we are now able to add the audience to this Activity and keep the Object untouched.

Proposed changes:

• Do not rely on the Transformer
• Create the full Activity
• Add audience to Activity

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• Send Follow Activity to inbox
• Check Outbox for Accept-Activity

Changelog entry

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Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Properly set to audience of Activity instead of changing the Follow Object.