Fix: Missing Actor in Outbox-Activities

[pfefferle]

In some cases the Actor of an Activity will not properly set and we wrongly set the inReplyTo for the Activity.

These fixes are cherry picked from #1562

Proposed changes:

• Add Actor before storing the Activity in the Outbox
• Add Actor before federating the Activity (for backwards compatibility)
• Remove reply-to from Activity context

Other information:

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

Testing instructions:

• Publish a post
• Check outbox item if Activity has an Actor

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

Ensure that an Activity is properly built before adding it to the Outbox.

[obenland]

In some cases the Actor of an Activity will not properly set.

Do we know which cases those are?

[pfefferle]

If you use the add_to_outbox() and let the function build the Activity, like with add_to_outbox( $activity, 'Announce', $id ).