Improve ls date switch parsing in Dired (Bug#6987).

* dired.el (dired-ls-sorting-switches, dired-sort-by-name-regexp):
Improve regexps (Bug#6987).
(dired-sort-toggle): Search more robustly for -t flag.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 026b05a723102c4d30ff22088a86640c40d81ed6..81061db87598ed9d7525b568407028b7abb76340 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,9 @@
 2010-09-05  Chong Yidong  <cyd@stupidchicken.com>
 
+       * dired.el (dired-ls-sorting-switches, dired-sort-by-name-regexp):
+       Improve regexps (Bug#6987).
+       (dired-sort-toggle): Search more robustly for -t flag.
+
        * files.el (get-free-disk-space): Search more robustly for
        "available" column.  Suggested by Ehud Karni
        <ehud@unix.mvs.co.il>.

diff --git a/lisp/dired.el b/lisp/dired.el
index ecc3b5bd47e2309b38564a7c37b5dc389446e166..3fdb82ca7d304890d5969e62e8ba335cdc355fd0 100644 (file)
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -3249,12 +3249,16 @@ variable `dired-listing-switches'.  To temporarily override the listing
 format, use `\\[universal-argument] \\[dired]'.")
 
 (defvar dired-sort-by-date-regexp
-  (concat "^-[^" dired-ls-sorting-switches
-         "]*t[^" dired-ls-sorting-switches "]*$")
+  (concat "\\(\\`\\| \\)-[^- ]*t"
+         ;; `dired-ls-sorting-switches' after -t overrides -t.
+         "[^ " dired-ls-sorting-switches "]*"
+         "\\(\\(\\`\\| +\\)\\(--[^ ]+\\|-[^- t"
+         dired-ls-sorting-switches "]+\\)\\)* *$")
   "Regexp recognized by Dired to set `by date' mode.")
 
 (defvar dired-sort-by-name-regexp
-  (concat "^-[^t" dired-ls-sorting-switches "]+$")
+  (concat "\\`\\(\\(\\`\\| +\\)\\(--[^ ]+\\|"
+         "-[^- t" dired-ls-sorting-switches "]+\\)\\)* *$")
   "Regexp recognized by Dired to set `by name' mode.")
 
 (defvar dired-sort-inhibit nil
@@ -3280,8 +3284,8 @@ The idea is to set this buffer-locally in special dired buffers.")
     (force-mode-line-update)))
 
 (defun dired-sort-toggle-or-edit (&optional arg)
-  "Toggle between sort by date/name and refresh the dired buffer.
-With a prefix argument you can edit the current listing switches instead."
+  "Toggle sorting by date, and refresh the Dired buffer.
+With a prefix argument, edit the current listing switches instead."
   (interactive "P")
   (when dired-sort-inhibit
     (error "Cannot sort this dired buffer"))
@@ -3292,24 +3296,24 @@ With a prefix argument you can edit the current listing switches instead."
 
 (defun dired-sort-toggle ()
   ;; Toggle between sort by date/name.  Reverts the buffer.
-  (setq dired-actual-switches
-       (let (case-fold-search)
-         (if (string-match " " dired-actual-switches)
-             ;; New toggle scheme: add/remove a trailing " -t"
-             (if (string-match " -t\\'" dired-actual-switches)
-                 (substring dired-actual-switches 0 (match-beginning 0))
-               (concat dired-actual-switches " -t"))
-           ;; old toggle scheme: look for some 't' switch and add/remove it
-           (concat
-            "-l"
-            (dired-replace-in-string (concat "[-lt"
-                                             dired-ls-sorting-switches "]")
-                                     ""
-                                     dired-actual-switches)
-            (if (string-match (concat "[t" dired-ls-sorting-switches "]")
-                              dired-actual-switches)
-                ""
-              "t")))))
+  (let ((sorting-by-date (string-match dired-sort-by-date-regexp
+                                      dired-actual-switches))
+       ;; Regexp for finding (possibly embedded) -t switches.
+       (switch-regexp "\\(\\`\\| \\)-\\([a-su-zA-Z]*\\)\\(t\\)\\([^ ]*\\)")
+       case-fold-search)
+    ;; Remove the -t switch.
+    (while (string-match switch-regexp dired-actual-switches)
+      (if (and (equal (match-string 2 dired-actual-switches) "")
+              (equal (match-string 4 dired-actual-switches) ""))
+         ;; Remove a stand-alone -t switch.
+         (setq dired-actual-switches
+               (replace-match "" t t dired-actual-switches))
+       ;; Remove a switch of the form -XtY for some X and Y.
+       (setq dired-actual-switches
+             (replace-match "" t t dired-actual-switches 3))))
+    ;; Now, if we weren't sorting by date before, add the -t switch.
+    (unless sorting-by-date
+      (setq dired-actual-switches (concat dired-actual-switches " -t"))))
   (dired-sort-set-modeline)
   (revert-buffer))