The Blend node's primary input is drawn with line artifacts on certain pixel rows

[Keavon]

The Blend node takes two inputs. But it is sampling the primary (top) input differently in a way that seems to cause artifacts, despite being identical inputs:

This is the bottom input which renders correctly (when Opacity is set to 0%):

This is the primary (top) input which displays the artifacts on some rows (when Opacity is set to 100%):

This can be reproduced by giving the 512x512 Lena image layer graph (topology shown above) a transform of 834.1126644638082 by 553.0840346358935 and a uniform scale of 723.0485350346357.