-#(define (inverted-flag stem-grob)
- (let* ((dir (if (eqv? (ly:grob-property stem-grob 'direction) UP) "d" "u"))
- (flag (retrieve-glyph-flag "" dir "" stem-grob))
- (stroke-style (ly:grob-property stem-grob 'stroke-style))
+#(define (inverted-flag grob)
+ (let* ((stem-grob (ly:grob-parent grob X))
+ (dir (if (eqv? (ly:grob-property stem-grob 'direction) UP) "d" "u"))
+ (flag (retrieve-glyph-flag "" dir "" grob))
+ (line-thickness (ly:staff-symbol-line-thickness grob))
+ (stem-thickness (ly:grob-property stem-grob 'thickness))
+ (stem-width (* line-thickness stem-thickness))
+ (stroke-style (ly:grob-property grob 'stroke-style))