nsresult SVGAnimatedPathSegList::SetBaseValueString(const nsAString& aValue) { SVGPathData newBaseValue; // The spec says that the path data is parsed and accepted up to the first // error encountered, so we don't return early if an error occurs. However, // we do want to throw any error code from setAttribute if there's a problem. nsresult rv = newBaseValue.SetValueFromString(aValue); // We must send these notifications *before* changing mBaseVal! Our baseVal's // DOM wrapper list may have to remove DOM items from itself, and any removed // DOM items need to copy their internal counterpart's values *before* we // change them. See the comments in // DOMSVGPathSegList::InternalListWillChangeTo(). DOMSVGPathSegList *baseValWrapper = DOMSVGPathSegList::GetDOMWrapperIfExists(GetBaseValKey()); if (baseValWrapper) { baseValWrapper->InternalListWillChangeTo(newBaseValue); } DOMSVGPathSegList* animValWrapper = nullptr; if (!IsAnimating()) { // DOM anim val wraps our base val too! animValWrapper = DOMSVGPathSegList::GetDOMWrapperIfExists(GetAnimValKey()); if (animValWrapper) { animValWrapper->InternalListWillChangeTo(newBaseValue); } } // Only now may we modify mBaseVal! // We don't need to call DidChange* here - we're only called by // nsSVGElement::ParseAttribute under Element::SetAttr, // which takes care of notifying. nsresult rv2 = mBaseVal.CopyFrom(newBaseValue); if (NS_FAILED(rv2)) { // Attempting to increase mBaseVal's length failed (mBaseVal is left // unmodified). We MUST keep any DOM wrappers in sync: if (baseValWrapper) { baseValWrapper->InternalListWillChangeTo(mBaseVal); } if (animValWrapper) { animValWrapper->InternalListWillChangeTo(mBaseVal); } return rv2; } return rv; }