I've improved the idea and am getting the hang of this more.
But I'm back to being unable to save again.
What you see works until "file-png-save" at the end.
I've tried to re-define the Image, Layer & Drawable though have clearly not succeeded. They are now commented out.
After merging the three layers, why can't I save them?
I've read that Python-Fu is easier to use. Would this easier to convert to Python?
(define (script-fu-save-png Image layer)
(gimp-displays-flush)
(define filename (car (gimp-image-get-filename Image)))
(define drawable (car (gimp-image-get-active-drawable Image)))
(script-fu-round-corners Image drawable 20 TRUE 0 0 15 TRUE FALSE)
(gimp-image-merge-visible-layers Image 0)
;(define layer (car (gimp-image-get-layer Image)))
;(define drawable (car (gimp-image-get-active-drawable Image)))
(file-png-save RUN-NONINTERACTIVE Image layer filename filename FALSE 9 FALSE FALSE FALSE FALSE FALSE)
;(gimp-quit 1)
)
(script-fu-register
"script-fu-save-png"
"<Image>/File/Save PNG & Exit"
"Save PNG file and exit GIMP."
"kes"
"kes"
"October 2017"
"RGB*, GRAY*, INDEXED*"
SF-IMAGE "Image" 0
SF-DRAWABLE "Layer" 0
)