413975 - GetCtx returning null does not mean we are an outer SVG

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Jonathan Watt [:jwatt]]

In nsSVGSVGElement.cpp we assume that if GetCtx() returns null then we are an outer SVG with an nsSVGOuterSVGFrame that has set our mViewportWidth and mViewportHeight. This is not the case of invalid SVG like:

<g id="docRoot">
  <svg>
    <stuff/>
  </svg>
</g>

Comment 1

[Robert Longson [:longsonr]]

Fix included in patch for bug 361920

Comment 2

[Robert Longson [:longsonr]]

Fixed by check in for bug 361920

Comment 3

[Brian Birtles (:birtles)]

Attachment: Test case

I'm running into this problem too in some of our mochitests. If we have a percentage length inside an SVG fragment whose parent is display:none we arrive at the same problem.

When we call nsSVGSVGElement::GetLength(), GetCtx() returns NULL and mViewportWidth and mViewportHeight are set to 0. So GetLength() returns 0 and nsSVGLength2::FixAxisLength returns 1e-20f. Hence the bogus result for this test.

Comment 4

[Robert Longson [:longsonr]]

Attachment: patch

This fixes the bug as originally described but the testcase is a different issue I think.

Comment 5

[Robert Longson [:longsonr]]

pushed http://hg.mozilla.org/mozilla-central/rev/de9d574b1a41

Comment 6

[Brian Birtles (:birtles)]

(In reply to comment #4)
> This fixes the bug as originally described but the testcase is a different
> issue I think.

Filed separate bug 628848 for that