ID 567796 - Specifying pixel coordinates on the Expression node results in overscan pixels being affected by the expression

Problem summary
Specifying pixel coordinates on the Expression node results in overscan pixels being affected by the expression.
 
Customer reported version
Nuke 14.1v1
 
Customer reported platform
CentOS 7
 
Steps to reproduce
 
1) Open Nuke.
 
2) Copy and paste the following script into the Node Graph:

CheckerBoard2 { inputs 0 format "1024 1024 0 0 1024 1024 1 square_1K" color0 {0.5 0.5 0.5 1} color1 {1 1 1 1} color2 {0.5 0.5 0.5 1} color3 {1 1 1 1} linecolor 0 centerlinecolor {0 0 0 0} centerlinewidth 0 name CheckerBoard1 selected true xpos -61 ypos -417}Transform { scale 0.85 center {512 512} name Transform2 selected true xpos -61 ypos -313}Constant { inputs 0 channels rgb color {0 1 0 0} format "1024 1024 0 0 1024 1024 1 square_1K" name Constant2 selected true xpos -294 ypos -385}Merge2 { inputs 2 name Merge1 selected true xpos -61 ypos -236}Reformat { type scale scale 0.85 resize none pbb true name Reformat1 selected true xpos -61 ypos -172}

 
3) Connect a Viewer to the script, open the Viewer's properties and check show overscan.
 
4) Add an Expression node upstream of the Viewer.
 
5) Add the rgba.red(1,1) - 0.5 expression to the expr0 knob.
 
6) Save, close and reopen the script. 
 
Expected behaviour
Overscan pixels should not by affected by the Expression node. You can see the expected result by doing rgba.red - 0.5 instead of rgba.red(1,1) - 0.5.
 
Actual behaviour
Using rgba.red(1,1) - 0.5on the Expression node have any impact on overscan pixels.
 
Workaround
Unknown.
 
Reproduced by support
This bug has been reproduced in:
Nuke 15.0v4 - Windows 10 - Linux Rocky 9
Nuke 10.0v1 - Windows 10 - Linux CentOS 7
 
Earliest version tested
Nuke 10.0v1
- This issue appears to be in all tested versions of the product