The layout is a recent (within the past year) change to allow placement of components in the corners, for example, the SVN plugin puts a button in the top right corner for certain actions. The coloring is wrong though, the bottom right corner in your 'error' image should be the same as that in the 'ok' image. The bottom scrollbar is somewhat narrower now in that it only spans the width of the text editing area and no longer includes the left gutter area or right side extension component area. This is an initentional change.
So it seems to me the bug here is the color in the bottom right corner is not the right color.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
The layout is a recent (within the past year) change to allow placement of components in the corners, for example, the SVN plugin puts a button in the top right corner for certain actions. The coloring is wrong though, the bottom right corner in your 'error' image should be the same as that in the 'ok' image. The bottom scrollbar is somewhat narrower now in that it only spans the width of the text editing area and no longer includes the left gutter area or right side extension component area. This is an initentional change.
So it seems to me the bug here is the color in the bottom right corner is not the right color.
Fixed in revision 24164, set corner background color to be the same as the adjacent scrollbar background color.