1168245 - Remove seemingly nonsensical code from nsDisplayTransform::GetDeltaToTransformOrigin

Status: RESOLVED FIXED

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

Comment 1

[Jonathan Watt [:jwatt]]

Attachment: patch

Removing this code doesn't cause anything to fail on Try.

Note that this section of code used to be unconditional before bug 923193, part 1, but I realized in that bug that nsDisplayTransform::GetFrameBoundsForTransform (now TransformReferenceBox::EnsureDimensionsAreCached) always returns a rect with zero offset. Therefore this bit of code could/can only have an effect if aBoundsOverride is non-null.

I can't actually see a way in which aBoundsOverride can end up with non-zero offset either though. For example, when nsDisplayTransform::TransformRect passes in an override bounds it sets the offset of the 'newBounds' object that is passes to {0,0}.

Perhaps this code is in some way related to UNIFIED_CONTINUATIONS, but the UNIFIED_CONTINUATIONS code has never worked. Rather than have this mysterious bit of code left here I think we should remove (it unless someone can explain it). If something break as a result of removing it, we can add it back with a nice explanatory comment this time!

Comment 2

[Matt Woodrow (:mattwoodrow)]

Comment on attachment 8610305 [details] [diff] [review]
patch

Review of attachment 8610305 [details] [diff] [review]:
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Let's give it a shot!

Comment 3

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3c9ee60d1ca5

Comment 4

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

https://hg.mozilla.org/mozilla-central/rev/3c9ee60d1ca5