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[Bug] Small images should be eagerly loaded
Closed, InvalidPublic


Steps to Reproduce

  1. Visit
  2. Scroll quickly to the bottom of the page

Expected Results

  • Tiny images are eagerly loaded

Actual Results

  • Tiny images are lazily loaded with the rest. E.g., if I go offline and then scroll, it's very obvious that small images have been lazily loaded:

Screenshot from 2018-07-11 12-26-03.png (986×1 px, 302 KB)

Environments Observed

Browser Version

  • Chromium v66.0.3359.181

OS Version

  • Ubuntu v18.04

Device Model

  • Desktop

Device Language

  • English

Event Timeline

What does "eagerly loaded" mean in this context? I'm not understanding the bug here.
Right now images will be lazily load as soon as they are scrolled into view. Are you saying that they should be loaded by some other heuristic?

Also, note that usually sections are collapsed by default. I'm only seeing flags downloaded when the sections they are in are expanded and scroll past them, but that seems expected behaviour to me.

We do have wgMFLazyLoadSkipSmallImages which will not lazy load small icons, but at some point we decided not to use this (see declined T128897), as there is evidence that these additional HTTP requests can throttle first paint and we didn't have the time or resources to investigate. Note, there is also evidence that loading them can cause performance issues (T185835). Is this what you are suggesting we do?

By "eager" I meant simply the opposite of "lazy." I was mistakenly thinking that small images were meant to be omitted and wasn't aware of the tickets you referenced.

Okay got it. Is there some way in the code/project page we can document this so it's more obvious? It has come up a few times before as unexpected.

@Jdlrobson, nope. In my mind, this was a longstanding bug that I had just never gotten around to filing a ticket for so I probably wouldn't have checked said page! D: