`history.back()` doesn't work after redirect to direct video page

[owi92]

This occurs whenever a user is redirected to a direct video page because of non-existent links. For example:

• https://tobira.opencast.org/lectures/d-baug/v/GuYZfNLh72B is a valid link since event GuYZfNLh72B is embedded as video block in lectures/d-baug
• It is part of the series "History and Theory of Architecture IX (Ursprung)"
• But when someone visits https://tobira.opencast.org/lectures/d-baug/v/GuYZfNLh72B, the videos inside the series block on the bottom of that page link to https://tobira.opencast.org/lectures/d-baug/v/{video_id}
• These urls do no exist if {video_id} isn't embedded on lectures/d-baug
• So a redirect to https://tobira.opencast.org/!v/{video_id} happens
• history.back() will attempt to revisit https://tobira.opencast.org/lectures/d-baug/v/{video_id}, which will then redirect to https://tobira.opencast.org/!v/{video_id} again and we're sort of stuck in a loop

I don't know if we can fix this for valid redirects to direct video pages, but we could change the way links inside series blocks on video pages are built.