Rebase

Disable deleting thick sidebar sources

Block deleting a sidebar source in thick threads

Rebase

Revert error handling change

ESLint

Simplify the code

Correctly handle thread children

That's right. There was a mistake here. During the review, I was comparing changes in this diff with changes from D14512 and I misunderstood changes to initialURI in that diff, making me think this diff is correct.

Remove redundant code

Apologies if the update was in progress, but passing back to you. Feel free to re-request review when the test plan has been updated (and performed) as requested above

It seems like you've updated the test plan to include the string "(image and video that requires and doesn't require transcoding)", which I suppose is an improvement, but very far from what I was looking for.

Review changes

In my opinion, inadequate testing of your changes is the reason our mobile releases have been blocked for the past 2 weeks.

In D14566#404086, @ashoat wrote:

It seems like we're discarding the processed media, since we're returning uploadURI to the caller (non-processed media). I hope I'm missing something here, as both @angelika and @bartek did not flag this...