images sometimes disappear when navigating back <> forward

[fabricedesre]

I can reproduce with these steps:

• open https://google.com.
• navigate to the link below the input box (currently a youtube tv page for me).
• navigate back with alt + left

Observed:
The Google logo has disappeared.

Expected:
The Google logo is displayed.

When alternating from the one page to the other with alt left and alt right, the image eventually re-appears.

@glennw could that be some WR image cache issue?

[jdm]

@gw3583 ^

[gw3583]

It's possible - it seems more likely to be related to Servo code though, since I'm not aware of anything similar occurring in Gecko.

[fabricedesre]

Ok thanks. Do you know by chance where I should look?

[gw3583]

I would probably start with the command line option to dump display lists, and see if anything is apparent from that.

In particular, I'd be looking to make sure that the Image Display Item is always there, and at the correct location.

From there, you could identify the ImageKey associated with that display item (and make sure it stays the same), and add some debugging to the servo image cache thread to check when the image is being added (and perhaps removed) to WR.

These might all be unrelated, but that's probably what I'd start with.