1492344 - Screenshots can't handle threads on Twitter

Status: NEW

(Firefox :: Screenshots, defect, P5)

Description

[Brian Carpenter [:geeknik]]

Attachment: Screenshot_2018-09-18 TMZ on Twitter.jpg

I was trying to capture the thread @ https://twitter.com/TMZ/status/1041340986432139264 but Screenshots is having trouble with the way in which Twitter pops out their threads. Fresh profile in Nightly, right click -> Take a Screenshot -> Save full page and the attached image is the result. Screenshots only saves the visible part of the thread while capturing the page that is behind the thread.

Comment 1

[Pablo]

I was able to replicate on windows10 and ubuntu20 using firefox 94.0.1
altho on my screenshot only just some of the threads appear and the rest are just blank

Comment 2

[Sam Foster [:sfoster] (he/him)]

Twitter - and lots of other sites - use a virtual list which dynamically creates and renders the document as you scroll through it. Typically a site might decide to prepare one viewport-worth of content below the part you are currently viewing. And to avoid the document becoming too large and performance getting very sluggish, the site may remove elements that are no longer visible. So, to support this, Screenshots would need to create a series of snapshots as you scroll and stitch them together into one image.

This seems a valid but niche use case. I want to keep this bug on file, but I don't expect we'll be able to fix this any time soon.