[webkit-reviews] review requested: [Bug 84657] Crash or assertion failure (m_isAnimating) when adding another instance of a SMIL animated element while the animation is running : [Attachment 169101] Allow lazy initialization of SVG XML animated properties.

[bugzilla-daemon at webkit.org]

Philip Rogers <pdr at google.com> has asked  for review:
Bug 84657: Crash or assertion failure (m_isAnimating) when adding another
instance of a SMIL animated element while the animation is running
https://bugs.webkit.org/show_bug.cgi?id=84657

Attachment 169101: Allow lazy initialization of SVG XML animated properties.
https://bugs.webkit.org/attachment.cgi?id=169101&action=review

------- Additional Comments from Philip Rogers <pdr at google.com>
Finally getting a patch up for this!

I explored tracking the animating properties in the animator so that we could
catch this case once instead of checking for it on every call to
resetAnimValToBaseVal. Unfortunately the checks required ended up polluting the
instance code which would affect performance outside animations. I also
explored the naive approach of invalidating the entire tree when we dynamically
add instances of animating elements (see comment in
SVGElementInstance::invalidateAllInstancesOfElement about this) but, again,
that ended up being terrible for performance.