lisp/desktop.el (desktop-clear): Be more careful about deleting frames.

[bpt/emacs.git] / lisp / sort.el

diff --git a/lisp/sort.el b/lisp/sort.el
index cd0b443..9493768 100644 (file)
--- a/lisp/sort.el
+++ b/lisp/sort.el
@@ -1,7 +1,7 @@
 ;;; sort.el --- commands to sort text in an Emacs buffer
 
-;; Copyright (C) 1986-1987, 1994-1995, 2001-2012
-;;   Free Software Foundation, Inc.
+;; Copyright (C) 1986-1987, 1994-1995, 2001-2013 Free Software
+;; Foundation, Inc.
 
 ;; Author: Howie Kaye
 ;; Maintainer: FSF
@@ -77,8 +77,13 @@ ENDKEYFUN moves from the start of the sort key to the end of the sort key.
 ENDKEYFUN may be nil if STARTKEYFUN returns a value or if it would be the
 same as ENDRECFUN.
 
-PREDICATE is the function to use to compare keys.  If keys are numbers,
-it defaults to `<', otherwise it defaults to `string<'."
+PREDICATE, if non-nil, is the predicate function for comparing
+keys; it is called with two arguments, the keys to compare, and
+should return non-nil if the first key should sort before the
+second key.  If PREDICATE is nil, comparison is done with `<' if
+the keys are numbers, with `compare-buffer-substrings' if the
+keys are cons cells (the car and cdr of each cons cell are taken
+as start and end positions), and with `string<' otherwise."
   ;; Heuristically try to avoid messages if sorting a small amt of text.
   (let ((messages (> (- (point-max) (point-min)) 50000)))
     (save-excursion
@@ -563,7 +568,8 @@ From a program takes two point or marker arguments, BEG and END."
       (insert (car ll)))))
 
 ;;;###autoload
-(defun delete-duplicate-lines (beg end &optional reverse adjacent interactive)
+(defun delete-duplicate-lines (beg end &optional reverse adjacent keep-blanks
+                               interactive)
   "Delete duplicate lines in the region between BEG and END.
 
 If REVERSE is nil, search and delete duplicates forward keeping the first
@@ -577,6 +583,9 @@ delete repeated lines only if they are adjacent.  It works like the utility
 this is more efficient in performance and memory usage than when ADJACENT
 is nil that uses additional memory to remember previous lines.
 
+If KEEP-BLANKS is non-nil (when called interactively with three C-u prefixes),
+duplicate blank lines are preserved.
+
 When called from Lisp and INTERACTIVE is omitted or nil, return the number
 of deleted duplicate lines, do not print it; if INTERACTIVE is t, the
 function behaves in all respects as if it had been called interactively."
@@ -586,6 +595,7 @@ function behaves in all respects as if it had been called interactively."
      (list (region-beginning) (region-end)
           (equal current-prefix-arg '(4))
           (equal current-prefix-arg '(16))
+          (equal current-prefix-arg '(64))
           t)))
   (let ((lines (unless adjacent (make-hash-table :weakness 'key :test 'equal)))
        line prev-line
@@ -600,14 +610,16 @@ function behaves in all respects as if it had been called interactively."
               (and (< (point) end) (not (eobp))))
        (setq line (buffer-substring-no-properties
                    (line-beginning-position) (line-end-position)))
-       (if (if adjacent (equal line prev-line) (gethash line lines))
-           (progn
-             (delete-region (progn (forward-line 0) (point))
-                            (progn (forward-line 1) (point)))
-             (if reverse (forward-line -1))
-             (setq count (1+ count)))
-         (if adjacent (setq prev-line line) (puthash line t lines))
-         (forward-line (if reverse -1 1)))))
+        (if (and keep-blanks (string= "" line))
+            (forward-line 1)
+          (if (if adjacent (equal line prev-line) (gethash line lines))
+              (progn
+                (delete-region (progn (forward-line 0) (point))
+                               (progn (forward-line 1) (point)))
+                (if reverse (forward-line -1))
+                (setq count (1+ count)))
+            (if adjacent (setq prev-line line) (puthash line t lines))
+            (forward-line (if reverse -1 1))))))
     (set-marker beg nil)
     (set-marker end nil)
     (when interactive