1242421 - [Static Analysis][Dereference before null check] In function DrawTargetCairo::FillGlyphs from DrawTargetCairo.cpp

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Andi [:andi]]

The Static Analysis tool Coverity added that variable mContext is null checked here:

>>  if (mContext && cairo_surface_status(cairo_get_group_target(mContext))) {
>>    gfxDebug() << "Ending FillGlyphs with a bad surface " << cairo_surface_status(cairo_get_group_target(mContext));
>>  }

Even though it's dereferenced earlier in the function. This checker is a false positive since we know for sure that at this step of the execution mContext has already been
created by the stack path:

>>	-> mozilla::gfx::DrawTargetCairo::InitAlreadyReferenced
>> 	mozilla::gfx::DrawTargetCairo::Init
>> 	mozilla::gfx::Factory::CreateDrawTargetForCairoSurface
>> 	gfxPlatform::CreateDrawTargetForSurface

So the null checker of mContext from FillGlyphs is useless.

Comment 1

[Andi [:andi]]

Attachment: MozReview Request: Bug 1242421 - remove useless null check. r?[e-mail]

Review commit: https://reviewboard.mozilla.org/r/32273/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/32273/

Comment 2

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

Comment on attachment 8711634 [details]
MozReview Request: Bug 1242421 - remove useless null check. r?[e-mail]

https://reviewboard.mozilla.org/r/32273/#review28969

Comment 3

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/441b3adc9f6e

Comment 4

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/441b3adc9f6e

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/441b3adc9f6e