(defun gnus-remove-from-range (range1 range2)
"Return a range that has all articles from RANGE2 removed from
RANGE1. The returned range is always a list. RANGE2 can also be a
-unsorted list of articles."
+unsorted list of articles. RANGE1 is modified by side effects, RANGE2
+is not modified."
(if (or (null range1) (null range2))
range1
(let (out r1 r2 r1_min r1_max r2_min r2_max
- (range1 range1)
- (range2 (if (listp (cdr range2))
- (sort range2 (lambda (e1 e2)
- (< (if (consp e1) (car e1) e1)
- (if (consp e2) (car e2) e2))))
- range2)))
+ (range2 (gnus-copy-sequence range2)))
(setq range1 (if (listp (cdr range1)) range1 (list range1))
- range2 (if (listp (cdr range2)) range2 (list range2))
+ range2 (sort (if (listp (cdr range2)) range2 (list range2))
+ (lambda (e1 e2)
+ (< (if (consp e1) (car e1) e1)
+ (if (consp e2) (car e2) e2))))
r1 (car range1)
r2 (car range2)
r1_min (if (consp r1) (car r1) r1)