1497275 - CanvasRenderingContext2D.drawImage (9 args) throws IndexSizeError when 0 is given to sWidth or sHeight

Status: UNCONFIRMED

(Core :: Graphics: Canvas2D, defect, P3)

Description

[Ryo Kato [:r_kato]]

Attachment: index.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:62.0) Gecko/20100101 Firefox/62.0

Steps to reproduce:

STR:
- Open the attached `index.html` file in Firefox (62 - 64)


Actual results:

3 `IndexSizeError` are thrown, though it seems the relevant spec does not state that.

spec: https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-drawimage

That errors are caused by test cases where 0 is given to `sWidth` or `sHeight` in drawImage()

Google Chrome 69 and Safari 12 don't cause this issue.


Expected results:

Throw no errors.

Comment 1

[Ryo Kato [:r_kato]]

An affected web site: https://vaaaaanquish.jp/bank

Comment 2

[Sotaro Ikeda [:sotaro]]

There is a similar issue in stackoverflow
https://stackoverflow.com/questions/19338032/canvas-indexsizeerror-index-or-size-is-negative-or-greater-than-the-allowed-a

Comment 3

[Sotaro Ikeda [:sotaro]]

(In reply to Ryo Kato [:r_kato] from comment #0)
> 
> spec:
> https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-drawimage

w3c spec still has "If the one of the source rectangle dimensions is zero, throws an IndexSizeError exception."
  https://www.w3.org/TR/2dcontext/#dom-context-2d-drawimage

Comment 4

[Sotaro Ikeda [:sotaro]]

MDN has an explanation. "INDEX_SIZE_ERR  If the canvas or source rectangle width or height is zero."
 https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/drawImage#Exceptions_thrown

Comment 5

[Sotaro Ikeda [:sotaro]]

I talked with :birtles. Then we concluded that it seems better to align to whatwg spec and update MDN.

Comment 6

[Sotaro Ikeda [:sotaro]]

:dholbert, can you comment to the bug? Thanks.

Comment 7

[Daniel Holbert [:dholbert]]

(In reply to Sotaro Ikeda [:sotaro] from comment #6)
> :dholbert, can you comment to the bug? Thanks.

Do you have a particular question that you'd like me to comment on?

(Your conclusion in comment 5 sounds reasonable; the WHATWG spec is the more authoritative one, when it comes to HTML element behavior.)

Comment 8

[Sotaro Ikeda [:sotaro]]

I just wanted to check if comment 5 is reasonable. Thanks.