REGRESSION: GuardMallloc crash in SVGListPropertyTearOff<SVGPointList>::processIncomingListItemWrapper
https://bugs.webkit.org/show_bug.cgi?id=154969

Patch by Said Abou-Hallawa <sabouhallawa@apple.com> on 2016-03-10
Reviewed by Darin Adler.

The life cycle of the SVGAnimatedPropertyTearOff::m_baseVal and m_animVal
was not correct. Like what was done in SVGAnimatedListPropertyTearOff,
m_baseVal and m_animVal have to be raw RefCounted pointers. When requested
through, SVGAnimatedPropertyTearOff::baseVal() and animVal() they are
encapsulated in a RefPtr to ensure they existence as long as they are
referenced. When the animated property object (which is stored in either
m_baseVal or m_animVal) is not referenced by anyone, it is going to be
deleted. In the destructor of their class, SVGAnimatedPropertyTearOff
will be notified of this deletion through propertyWillBeDeleted() to clean
its member m_baseVal or m_animVal.

* bindings/scripts/CodeGeneratorJS.pm:
(NativeToJSValue): Now all the SVG animated property return RefPtrs. In
addition to that, SVGViewSpec.transform also returns
RefPtr<SVGTransformListPropertyTearOff>.

* svg/properties/SVGAnimatedListPropertyTearOff.h:
(WebCore::SVGAnimatedListPropertyTearOff::animVal):
(WebCore::SVGAnimatedListPropertyTearOff::currentAnimatedValue):
(WebCore::SVGAnimatedListPropertyTearOff::animationStarted):
(WebCore::SVGAnimatedListPropertyTearOff::animationEnded):
(WebCore::SVGAnimatedListPropertyTearOff::synchronizeWrappersIfNeeded):
(WebCore::SVGAnimatedListPropertyTearOff::isAnimating):
(WebCore::SVGAnimatedListPropertyTearOff::propertyWillBeDeleted):
Change propertyWillBeDeleted() to be virtual and make it takes an SVGProperty*.
Rename m_animatingAnimVal to be m_animatedProperty. Add isAnimating() which
returns true if m_animatedProperty is not null. Use isAnimating() instead of
m_isAnimating because it's deleted from the base class.

* svg/properties/SVGAnimatedProperty.cpp:
(WebCore::SVGAnimatedProperty::SVGAnimatedProperty):
(WebCore::SVGAnimatedProperty::~SVGAnimatedProperty):
* svg/properties/SVGAnimatedProperty.h:
(WebCore::SVGAnimatedProperty::isAnimating):
(WebCore::SVGAnimatedProperty::propertyWillBeDeleted):
Delete m_isAnimating since its value can be deduced from the value of
m_animatedProperty in the derived class. Add propertyWillBeDeleted() and
isAnimating() as virtual functions with the default behavior.

* svg/properties/SVGAnimatedPropertyTearOff.h:
(WebCore::SVGAnimatedPropertyTearOff::baseVal):
(WebCore::SVGAnimatedPropertyTearOff::animVal):
Like SVGAnimatedListPropertyTearOff::baseVal() and animVal() create the
value if it does not exist. Keep a raw RefCounted pointer but return a
RefPtr.

(WebCore::SVGAnimatedPropertyTearOff::isAnimating):
(WebCore::SVGAnimatedPropertyTearOff::propertyWillBeDeleted):
Override virtual functions.

(WebCore::SVGAnimatedPropertyTearOff::currentAnimatedValue):
(WebCore::SVGAnimatedPropertyTearOff::animationStarted):
(WebCore::SVGAnimatedPropertyTearOff::animationEnded):
(WebCore::SVGAnimatedPropertyTearOff::animValWillChange):
(WebCore::SVGAnimatedPropertyTearOff::animValDidChange):
Replace m_isAnimating with isAnimating(). Ensure that we get a new animated
property through animVal() and store it in a RefPtr to ensure it will not
go away while animating.

* svg/properties/SVGAnimatedStaticPropertyTearOff.h:
(WebCore::SVGAnimatedStaticPropertyTearOff::isAnimating):
(WebCore::SVGAnimatedStaticPropertyTearOff::currentAnimatedValue):
(WebCore::SVGAnimatedStaticPropertyTearOff::animationStarted):
(WebCore::SVGAnimatedStaticPropertyTearOff::animationEnded):
(WebCore::SVGAnimatedStaticPropertyTearOff::animValWillChange):
(WebCore::SVGAnimatedStaticPropertyTearOff::animValDidChange):
Add isAnimating() and replace all the instances of m_isAnimating with calls
to isAnimating().

* svg/properties/SVGPropertyTearOff.h:
(WebCore::SVGPropertyTearOff::animatedProperty):
(WebCore::SVGPropertyTearOff::setAnimatedProperty):
(WebCore::SVGPropertyTearOff::contextElement):
(WebCore::SVGPropertyTearOff::SVGPropertyTearOff):
(WebCore::SVGPropertyTearOff::~SVGPropertyTearOff):
SVGPropertyTearOff is what SVGAnimatedPropertyTearOff creates for its
baseVal() and animVal() values. These values can be null anytime once
they are not referenced. The SVGAnimatedPropertyTearOff holds only raw
RefCounted pointer for them. So (1) SVGPropertyTearOff needs to hold a
RefPtr for its SVGAnimatedProperty and (2) it needs to notify its
SVGAnimatedProperty when it's deleted by calling propertyWillBeDeleted()
from the destructor. Also there is no need to get the contextElement()
and save it in class member, m_contextElement since it can be always be
retrieved from SVGAnimatedProperty::contextElement().

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@197967 268f45cc-cd09-0410-ab3c-d52691b4dbfc
8 files changed