Pinned posts cause profile timeline to skip into the past when scrolling

1. Pin a post from a week ago.
2. Scroll through posts.
3. Suddenly you've jumped back a week, even though you have many posts newer than that.

This is probably fixed by not adding the pinned posts to the profile timeline twice.

sounds like a bigger issue. Although i don't like the idea of NOT adding pinned posts twice.

I have the same issue on my profile timeline. https://ministry.moonbutt.science/winzstd

I pinned a post right after I'd posted it. I don't remember have I pinned it twice, probably not.

Currenlty, there are exactly the 20 latest posts on my timeline. The posts between these and the pinned post don't appear.

And there https://ministry.moonbutt.science/commagray

• Two pinned posts;
• 20 latest posts are visible;
• The next posts before the first pinned post are skipped;
• All the posts between the two pinned posts are skipped;
• All the post earlier than the first pinned post are visible.

I was trying to reproduce this issue. Anyone still seeing it? More info would help track down the issue.

@wyatt777 you can visit my profile: https://shigusegubu.club/hj

Basically what is happening:

FE fetches recent posts and pinned posts. In most cases if there are pinned posts they are quite old. What ends up happening is that system knows 20 recent post and 1 old one, when fetching older posts it uses the oldest post it knows as a reference, so instead of querying posts starting from last recent post it fetches them using pinned post because it's the oldest one.

This issue is somewhat related to the duplicated pinned posts #549 (closed) and not quite easy to actually fix it properly without ripping pinned posts out of context and other issues.

Hi @hj thanks.

In src/modules/statuses.js it seems to get the maxId (oldest post) using lodash maxBy. If maxBy was rewritten to ignore pinned posts, it might fix this.

Something like:

const maxBy = (array, iteratee) => {
  let result
  if (array == null) {
    return result
  }
  let computed
  for (const value of array) {
    let current = 0
    if (!value.pinned) {
      current = value[iteratee]
    }
    if (current != null && (computed === undefined
      ? (!isSymbol(current))
      : (current > computed)
    )) {
      computed = current
      result = value
    }
  }
  return result
}

i.e. never use pinned posts to do the API call for timelines.

On local the pinned posts are still at the top and show in their original timeline place below. If I can reproduce the original issue locally I will test it out with that.

You can ignore this until I test it locally.

More on how maxId is used so it can be reviewed easier. Time line fetcher I was able to reproduce it locally.

@hj I was able to resolve this locally in src/modules/statuses.js

fetchPinnedStatuses: I added another variable here isPinned set to true.

When it is true addNewStatuses does not reset the maxId or minId of the timeline.

Local testing: multiple / single pinned statuses are still at the top of the timeline. The timeline no longer skips statuses as described in this issue.

mentioned in merge request !850 (merged)

mentioned in commit a1c50c3f

I think there's something else going on here. Every time you hit the bottom of the statuses of a profile with pinned statuses they get loaded again.

pinned_profile

@feld basically when displaying user timeline it displays all known posts sorted by their id (read = time, for local users).

Internally it knows about:

• User's recent posts
• User's pinned posts (which could be months old)

It displays in UI, in separate lists:

• User's pinned posts
• All user's posts

All users's posts have certain filters so that they don't contain pinned posts if they are the very beginning, so you don't get situations like this

Post 1 [Pinned]
Post 1 [Pinned]
Post 2
Post 3
Post 4

however since FE knows about pinned posts it will show it at the bottom of all known posts because they are the oldest.

Post 99 [Pinned]
Post 1
Post 2
Post 3
Post 4
Post 99 [Pinned]

We need to somehow know whether we should show old pinned post in all posts list or not, so that can render such situations correctly:

Post 5 [pinned]
Post 1
Post 2
Post 3
Post 4
Post 5 [pinned]
Post 6

This issue was about that loading was broken (it's fixed now) since it essentially started loading posts after the oldest post (which is pinned, now ignored), i suggest opening another issue, you may even copy-paste my comment explaining the situation.

I don't see this behavior, has this been fixed?

i see it on my instance on my profile

at least the issue with "pinned post always at the bottom"

the "loading jumps a week" however has been fixed

I found a backend bug relating to this...

it's a frontend bug, really, as I mentioned above.

yeah, i know, just found an additional bug :)

closed