111991 - SVG DOM should throw exception on negative values for some attributes

Status: RESOLVED WONTFIX

(Core :: SVG, defect)

Description

[Håkan Waara]

Spun off bug #111492...

For some attributes, such as the rectangle's rx/ry, negative values are not 
allowed. Per the W3C spec, we should return some sort of W3C exception there -- 
currently we just jump out of the |nsSVGRectFrame::ConstructPath| function.

This error checking should be done higher up in the system, for all attributes 
that do not allow negative values.

Comment 1

[Jonathan Watt [:jwatt]]

Mass reassign of SVG bugs that aren't currently being worked on by Alex to
[e-mail]. If you think someone should be assigned to your bug you can
join the #svg channel on mozilla.org's IRC server ( irc://irc.mozilla.org/svg )
where you can try to convince one of the SVG hackers to work on it. We aren't
always there, so if you don't get a response straight away please try again later. 

Comment 2

[Jonathan Watt [:jwatt]]

Actually per the W3C spec we should be putting the document into error rather
than throwing.

http://w3.org/TR/SVG11/implnote.html#ErrorProcessing

However, I don't see us doing this any time soon, and I have to admit I'd also
prefer to throw when an attempt is made to give such a property a negative value
using the DOM.

Comment 3

[Jonathan Watt [:jwatt]]

We do the parsing in nsSVGLength2::SetBaseValueString (called from nsSVGElement::ParseAttribute). At that point we only know we're a length and not which attribute we belong to. That's a problem since we need that information. E.g. 'x' can have a negative value, but 'width' can not.

Comment 4

[Robert Longson [:longsonr]]

Neither Chrome nor Safari throw. They do warn on parsing so perhaps that's all we can/should do here.

Comment 5

[Robert Longson [:longsonr]]

Attachment: Bug 111991 - Warn if we parse a negative length that's not supposed to be negative r=emilio