1243359 - [Static Analysis][Uninitialized scalar field] In function ScrollWheelInput::ScrollWheelInput

Status: RESOLVED FIXED

(Core :: Widget, defect)

Description

[Andi [:andi]]

The Static Analysis tool Coverity added that variable mScrollSeriesNumber is not initialized when constructor:

>> ScrollWheelInput::ScrollWheelInput(const WidgetWheelEvent& aWheelEvent)

get's called.

This variable is initialed in the 2nd constructor:

>>  ScrollWheelInput(uint32_t aTime,
>>                   TimeStamp aTimeStamp,
>>                   Modifiers aModifiers,
>>                   ScrollMode aScrollMode,
>>                   ScrollDeltaType aDeltaType,
>>                   const ScreenPoint& aOrigin,
>>                   double aDeltaX,
>>                   double aDeltaY)

The only place where this variable is attributed a value outside of the 2nd constructor is:

>>  if (!mLastEventTime.IsNull() &&
>>      (aEvent.mTimeStamp - mLastEventTime).ToMilliseconds() > kScrollSeriesTimeoutMs)
>>  {
>>    mScrollSeriesCounter = 0;
>>  }
>>  aEvent.mScrollSeriesNumber = ++mScrollSeriesCounter;

The only place where this variable is used is in AsyncPanZoomController::GetScrollWheelDelta(const ScrollWheelInput& aEvent) const but i don't know for sure what constructor was used to build
aEvent nor if it already passed through WheelBlockState::Update(ScrollWheelInput& aEvent).

Comment 1

[Andi [:andi]]

Attachment: MozReview Request: Bug 1243359 - initialize mScrollSeriesNumber in all ScrollWheelInput constructors. r?roc

Review commit: https://reviewboard.mozilla.org/r/32601/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/32601/

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8712653 [details]
MozReview Request: Bug 1243359 - initialize mScrollSeriesNumber in all ScrollWheelInput constructors. r?roc

https://reviewboard.mozilla.org/r/32601/#review29529

Comment 3

[Carsten Book [:Tomcat]]

this failed to apply:

patching file widget/InputData.cpp
Hunk #1 FAILED at 373
1 out of 1 hunks FAILED -- saving rejects to file widget/InputData.cpp.rej
patch failed to apply
abort: fix up the merge and run hg transplant --continue

Comment 4

[Andi [:andi]]

i don't see why this would fail, i've applied it to the latest revision: from mozilla-central 281836 and it worked. Can you please givbe me more details?

Comment 5

[Andi [:andi]]

Comment on attachment 8712653 [details]
MozReview Request: Bug 1243359 - initialize mScrollSeriesNumber in all ScrollWheelInput constructors. r?roc

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/32601/diff/1-2/

Comment 6

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/13f6aa359a3c

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/13f6aa359a3c