Specify encoding of the bookmark file

* lisp/bookmark.el (bookmark-insert-file-format-version-stamp):
Accept an argument CODING and include a 'coding:' cookie in the
bookmark file preamble.
(bookmark-upgrade-file-format-from-0): Call
'bookmark-insert-file-format-version-stamp' with the file buffer's
encoding, as detected when it was read.
(bookmark-file-coding-system): New variable.
(bookmark-load): Set bookmark-file-coding-system to the encoding
of the loaded file.
(bookmark-write-file): Bind coding-system-for-write to either the
user setting via "C-x RET c" or to the existing file encoding,
defaulting to 'utf-8-emacs'.  Update the value of
bookmark-file-coding-system.  (Bug#25365)

1 files changed, 18 insertions, 8 deletions

diff --git a/lisp/bookmark.el b/lisp/bookmark.el
index 3440a52ad4d..e18362bca95 100644
--- a/lisp/bookmark.el
+++ b/lisp/bookmark.el
@@ -267,6 +267,8 @@ or the deprecated form (BOOKMARK-NAME PARAM-ALIST).
 (defvar bookmarks-already-loaded nil
   "Non-nil if and only if bookmarks have been loaded from `bookmark-default-file'.")
 
+(defvar bookmark-file-coding-system nil
+  "The coding-system of the last loaded or saved bookmark file.")
 
 ;; more stuff added by db.
 
@@ -689,7 +691,7 @@ This expects to be called from `point-min' in a bookmark file."
   (let* ((old-list (bookmark-alist-from-buffer))
          (new-list (bookmark-upgrade-version-0-alist old-list)))
     (delete-region (point-min) (point-max))
-    (bookmark-insert-file-format-version-stamp)
+    (bookmark-insert-file-format-version-stamp buffer-file-coding-system)
     (pp new-list (current-buffer))
     (save-buffer))
   (goto-char (point-min))
@@ -726,11 +728,14 @@ This expects to be called from `point-min' in a bookmark file."
       (error "Bookmark file format version strangeness")))))
 
 
-(defun bookmark-insert-file-format-version-stamp ()
-  "Insert text indicating current version of bookmark file format."
+(defun bookmark-insert-file-format-version-stamp (coding)
+  "Insert text indicating current version of bookmark file format.
+CODING is the symbol of the coding-system in which the file is encoded."
+  (if (memq (coding-system-base coding) '(undecided prefer-utf-8))
+      (setq coding 'utf-8-emacs))
   (insert
-   (format ";;;; Emacs Bookmark Format Version %d ;;;;\n"
-           bookmark-file-format-version))
+   (format ";;;; Emacs Bookmark Format Version %d ;;;; -*- coding: %S -*- \n"
+           bookmark-file-format-version (coding-system-base coding)))
   (insert ";;; This format is meant to be slightly human-readable;\n"
           ";;; nevertheless, you probably don't want to edit it.\n"
           ";;; "
@@ -1417,14 +1422,17 @@ for a file, defaulting to the file defined by variable
   (with-current-buffer (get-buffer-create " *Bookmarks*")
     (goto-char (point-min))
     (delete-region (point-min) (point-max))
-    (let ((print-length nil)
+    (let ((coding-system-for-write
+           (or coding-system-for-write
+               bookmark-file-coding-system 'utf-8-emacs))
+          (print-length nil)
           (print-level nil)
           ;; See bug #12503 for why we bind `print-circle'.  Users
           ;; can define their own bookmark types, which can result in
           ;; arbitrary Lisp objects being stored in bookmark records,
           ;; and some users create objects containing circularities.
           (print-circle t))
-      (bookmark-insert-file-format-version-stamp)
+      (bookmark-insert-file-format-version-stamp coding-system-for-write)
       (insert "(")
       ;; Rather than a single call to `pp' we make one per bookmark.
       ;; Apparently `pp' has a poor algorithmic complexity, so this
@@ -1440,6 +1448,7 @@ for a file, defaulting to the file defined by variable
         (condition-case nil
             (write-region (point-min) (point-max) file)
           (file-error (message "Can't write %s" file)))
+        (setq bookmark-file-coding-system coding-system-for-write)
         (kill-buffer (current-buffer))
         (bookmark-maybe-message
          "Saving bookmarks to file %s...done" file)))))
@@ -1521,7 +1530,8 @@ unique numeric suffixes \"<2>\", \"<3>\", etc."
                     (expand-file-name bookmark-default-file))
                    file)
                   (setq bookmarks-already-loaded t))
-              (bookmark-bmenu-surreptitiously-rebuild-list))
+              (bookmark-bmenu-surreptitiously-rebuild-list)
+              (setq bookmark-file-coding-system buffer-file-coding-system))
           (error "Invalid bookmark list in %s" file)))
       (kill-buffer (current-buffer)))
     (if (null no-msg)