401795 - Canvas toDataURL does not accept excess arguments

Status: RESOLVED DUPLICATE of bug 564388

(Core :: Graphics: Canvas2D, defect, P2)

Description

[Philip Taylor]

User-Agent:       Opera/9.24 (X11; Linux i686; U; en)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a9pre) Gecko/2007103004 Minefield/3.0a9pre

The spec explicitly says about the toDataURL(type) method:

   "Arguments other than the type must be ignored, and must not cause the user agent to raise an exception (as would normally occur if a method was called with the wrong number of arguments). A future version of this specification will probably allow extra parameters to be passed to toDataURL() to allow authors to more carefully control compression settings, image metadata, etc."


Reproducible: Always

Steps to Reproduce:
1. Call toDataURL with arguments other than type, from unprivileged content.

Actual Results:  
NS_ERROR_DOM_SECURITY_ERR is thrown.

Expected Results:  
The extra arguments should be ignored.

It looks like the extra arguments are used for some proprietary purpose by trusted code (hence the security exception in untrusted code). Since it directly contradicts the spec, either the implementation or the spec should be changed so they're consistent.

Comment 1

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

This is required to pass

http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.arguments.1.html
http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.arguments.2.html
http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.arguments.3.html
http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.jpeg.quality.basic.html
http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.jpeg.quality.notnumber.html
http://www.w3c-test.org/html/tests/approved/canvas/toDataURL.jpeg.quality.outsiderange.html

Comment 3

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

Fixed in bug 564388.