patch 8.0.0453: adding fold marker creates new comment
Problem: Adding fold marker creates new comment.
Solution: Use an existing comment if possible. (LemonBoy, closes #1549)
diff --git a/src/proto/ops.pro b/src/proto/ops.pro
index ef044e7..0740dda 100644
--- a/src/proto/ops.pro
+++ b/src/proto/ops.pro
@@ -38,6 +38,7 @@
int preprocs_left(void);
int get_register_name(int num);
void ex_display(exarg_T *eap);
+char_u *skip_comment(char_u *line, int process, int include_space, int *is_comment);
int do_join(long count, int insert_space, int save_undo, int use_formatoptions, int setmark);
void op_format(oparg_T *oap, int keep_cursor);
void op_formatexpr(oparg_T *oap);