0f9eb6566f
The actor-shader-effect test actors are 50px wide, but we check the 51st pixel. This went along undetected until "clutter: Avoid rounding compensation when invalidating 2D actors" because the paint volumes were made slightly bigger and the shaders paint all over them (I guess nobody noticed those actors being actually ~52px wide). Update the test to check the middle of the opposite edge, so we keep neatly rounded numbers. (cherry picked from commit 1d73533f786b8f83fcffae7e5f5965d3b1f4e57a)