1297211 - CanvasRenderingContext2D.drawImage can throw 0x80040111 (NS_ERROR_NOT_AVAILABLE)

Status: RESOLVED FIXED

(Core :: Canvas: 2D, defect)

Description

[Oriol Brufau [:Oriol]]

Run this code in the console:

    document.createElement("canvas").getContext("2d")
    .drawImage(new Image(), 0, 0, 0, 0);

Result:

    [Exception... "Component is not available"
     nsresult: "0x80040111 (NS_ERROR_NOT_AVAILABLE)"
     location: "JS frame :: debugger eval code :: <TOP_LEVEL> :: line 1"
     data: no]

I think that [checking the usability of the image argument][1] should return "bad" because the intrinsic width and height of the image are 0.

And then [drawImage][2] should abort, but without throwing.

Chrome and Edge don't throw.

[1]: https://html.spec.whatwg.org/multipage/scripting.html#check-the-usability-of-the-image-argument
[2]: https://html.spec.whatwg.org/multipage/scripting.html#dom-context-2d-drawimage

Comment 1

[Jeff Muizelaar [:jrmuizel]]

Can you submit a webplatform test to https://github.com/w3c/web-platform-tests? That will make sure everyone has the same behaviour.

Comment 2

[Oriol Brufau [:Oriol]]

The test already exists:

https://github.com/w3c/web-platform-tests/blob/master/2dcontext/drawing-images-to-the-canvas/2d.drawImage.incomplete.nosrc.html

However, Firefox expects it to fail:

https://dxr.mozilla.org/mozilla-central/rev/b7f7ae14590aced450bb0b0469dfb38edd2c0ace/testing/web-platform/meta/2dcontext/drawing-images-to-the-canvas/2d.drawImage.incomplete.nosrc.html.ini

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Ok, great. Lee do you think you'd have time to look at this while I'm away next week? It should be pretty easy to fix.

Comment 4

[Lee Salzman [:lsalzman]]

Attachment: treat an empty src as available in image requests for canvas2d drawImage

This marks an image element with an empty source as available by letting its size be accessed so that canvas drawImage won't throw an error anymore, as the spec mandates.

This also fixes our results on several web platform tests that check for this behavior.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/52eed50488c2
treat an empty src as available in image requests for canvas2d drawImage. r=mchang

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/52eed50488c2