1149194 - use of uninitialized value in Animation.h

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Tom Tromey :tromey]

While looking into another bug, I ran ./browser/devtools/storage/test/browser_storage_dynamic_updates.js
under valgrind.  This showed the appended error due to using an uninitalized value.

I believe the bug is that ComputedTimingFunction::operator== unconditionally compares both the
mTimingFunction and mSteps members; but ComputedTimingFunction::Init will only initialize one
member, not both.

I'll attach a patch that fixes the problem.


Valgrind output:

==7192== Conditional jump or move depends on uninitialised value(s)
==7192==    at 0x83437EF: operator== (Animation.h:119)
==7192==    by 0x83437EF: operator== (Animation.h:143)
==7192==    by 0x83437EF: operator==<nsTArrayInfallibleAllocator> (nsTArray.h:874)
==7192==    by 0x83437EF: operator== (Animation.h:172)
==7192==    by 0x83437EF: operator==<nsTArrayInfallibleAllocator> (nsTArray.h:874)
==7192==    by 0x83437EF: operator!= (nsTArray.h:884)
==7192==    by 0x83437EF: nsAnimationManager::CheckAnimationRule(nsStyleContext*, mozilla::dom::Element*) (nsAnimationManager.cpp:336)
==7192==    by 0x8367506: nsStyleSet::GetContext(nsStyleContext*, nsRuleNode*, nsRuleNode*, nsIAtom*, nsCSSPseudoElements::Type, mozilla::dom::Element*, unsigned int) (nsStyleSet.cpp:890)
==7192==    by 0x83678A6: nsStyleSet::ResolveStyleFor(mozilla::dom::Element*, nsStyleContext*, TreeMatchContext&) (nsStyleSet.cpp:1293)
==7192==    by 0x839DF4B: mozilla::ElementRestyler::RestyleSelf(nsIFrame*, nsRestyleHint, unsigned int*) (RestyleManager.cpp:3232)
==7192==    by 0x839D511: mozilla::ElementRestyler::Restyle(nsRestyleHint) (RestyleManager.cpp:2764)
==7192==    by 0x839DA3D: mozilla::ElementRestyler::RestyleContentChildren(nsIFrame*, nsRestyleHint) (RestyleManager.cpp:3987)
==7192==    by 0x839DB7B: mozilla::ElementRestyler::RestyleChildren(nsRestyleHint) (RestyleManager.cpp:3527)
==7192==    by 0x839D6C0: mozilla::ElementRestyler::Restyle(nsRestyleHint) (RestyleManager.cpp:2869)
==7192==    by 0x839DA3D: mozilla::ElementRestyler::RestyleContentChildren(nsIFrame*, nsRestyleHint) (RestyleManager.cpp:3987)
==7192==    by 0x839DB7B: mozilla::ElementRestyler::RestyleChildren(nsRestyleHint) (RestyleManager.cpp:3527)
==7192==    by 0x839D6C0: mozilla::ElementRestyler::Restyle(nsRestyleHint) (RestyleManager.cpp:2869)
==7192==    by 0x839DA3D: mozilla::ElementRestyler::RestyleContentChildren(nsIFrame*, nsRestyleHint) (RestyleManager.cpp:3987)

Comment 1

[Tom Tromey :tromey]

Attachment: don't use uninitialized value in ComputedTimingFunction::operator==

Comment 2

[Brian Birtles (:birtles, Feb 26~ parental leave)]

Comment on attachment 8585569 [details] [diff] [review]
don't use uninitialized value in ComputedTimingFunction::operator==

Review of attachment 8585569 [details] [diff] [review]:
-----------------------------------------------------------------

Thanks for doing this!

Comment 3

[Tom Tromey :tromey]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=d6f737f74461

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3e9e33791d34

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3e9e33791d34