Transposing a clef by interval "0" leads to incorrect output, and it
does not make logical sense.
This commit prevents the transposition from being "0" and fixes the
output.
(let ((e '())
(c0 0)
(oct 0)
(let ((e '())
(c0 0)
(oct 0)
- (match (string-match "^(.*)([_^])([0-9]+)$" clef-name)))
+ (match (string-match "^(.*)([_^])([1-9][0-9]*)$" clef-name)))
(if match
(begin
(set! clef-name (match:substring match 1))
(if match
(begin
(set! clef-name (match:substring match 1))