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@flar I tweaked the patch to simplify the logic and added a unit test. Would you mind taking a look again? Thanks.

Also, do we have a test that confirms the behavior with raster cache checkerboarding off, but offscreen checkerboarding on? That would be nice, especially since we just got the 2 confused.

Yes, those tests are here
https://github.com/flutter/engine/blob/main/flow/layers/checkerboard_layertree_unittests.cc

Also, do we have a test that confirms the behavior with raster cache checkerboarding off, but offscreen checkerboarding on? That would be nice, especially since we just got the 2 confused.

Yes, those tests are here https://github.com/flutter/engine/blob/main/flow/layers/checkerboard_layertree_unittests.cc

I don't see them. All of those tests are outside of caching as far as I can tell...?

With offscreen vs rastercache checkerboarding being 2 flags we should be checking that all 4 combinations of

• rastercache checkerboarding of content that has checkerboarded offscreen layers
• layer-checkerboarding without any caching
• rastercache checkerboarding without any offscreen layers inside them
• neither

I think we already test the last 3, but we have no test of layer caching a layer that has a child that also has a saveLayer that will be offscreen-checkerboarded, do we?

Also, do we have a test that confirms the behavior with raster cache checkerboarding off, but offscreen checkerboarding on? That would be nice, especially since we just got the 2 confused.

Yes, those tests are here https://github.com/flutter/engine/blob/main/flow/layers/checkerboard_layertree_unittests.cc

I don't see them. All of those tests are outside of caching as far as I can tell...?

With offscreen vs rastercache checkerboarding being 2 flags we should be checking that all 4 combinations of

• rastercache checkerboarding of content that has checkerboarded offscreen layers
• layer-checkerboarding without any caching
• rastercache checkerboarding without any offscreen layers inside them
• neither

I think we already test the last 3, but we have no test of layer caching a layer that has a child that also has a saveLayer that will be offscreen-checkerboarded, do we?

I see, that test looks a little hard to implement though. Can we get this patch to land first? I filed an issue flutter/flutter#107676, we can address it in another PR.