Should we clear image data or not after the image is adopted into a data document.

[allstarschh]

See the test in http://software.hixie.ch/utilities/js/live-dom-viewer/?saved=5501

Firefox/Edge/IE still keeps the width/height and the image can be drawn into canvas,
whereas Safari and Chrome reset the image data, and the width/height are both 0 and the canvas is empty.

[bzbarsky]

@annevk

[annevk]

I don't know much about the img element, but reading through it I get the impression Edge and Firefox might be correct. Currently "adopting steps" are a "relevant mutation". That triggers "update the image data" which would hang in step 1.2 given that this img element's node document is not the active document. So no internal state would be updated. I'm not sure it's ideal for the algorithm to just hang though, that seems rather crappy.

@zcorpan?

[zcorpan]

Indeed the spec doesn't copy internal state. I don't know if that should change. Are there any known web compat issues?

The 1.2 step I tried to model after Gecko I believe. See ResponsiveImagesCG/picture-element@ee68507

In particular before that change the algorithm would just abort if the document is not active, and then nothing would happen when the document became active. But there could be better ways to specify that logic.