@@ -423,17 +423,19 @@ This procedure returns #t on success."
(port-encoding in)))
(post-bv (get-bytevector-all in))
(str* (proc str)))
- ;; Verify the edited expression is still a scheme expression.
- (call-with-input-string str* read)
- ;; Update the file with edited expression.
- (with-atomic-file-output file
- (lambda (out)
- (put-bytevector out pre-bv)
- (display str* out)
- ;; post-bv maybe the end-of-file object.
- (when (not (eof-object? post-bv))
- (put-bytevector out post-bv))
- #t))))))))
+ ;; Modify FILE only if there are changes.
+ (unless (string=? str* str)
+ ;; Verify the edited expression is still a scheme expression.
+ (call-with-input-string str* read)
+ ;; Update the file with edited expression.
+ (with-atomic-file-output file
+ (lambda (out)
+ (put-bytevector out pre-bv)
+ (display str* out)
+ ;; post-bv maybe the end-of-file object.
+ (when (not (eof-object? post-bv))
+ (put-bytevector out post-bv))
+ #t)))))))))
;;;