(decode-coding-region-as-inserted-from-file): New function.

diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index 909ba315b77686733665de2ec6af1da6ab969671..aa14f442bd09f647a2cfcff272f8de2b385192d7 100644 (file)
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -1899,6 +1899,33 @@ or a function symbol which, when called, returns such a cons cell."
                   (cons (cons regexp coding-system)
                         network-coding-system-alist)))))))
 
+(defun decode-coding-region-as-inserted-from-file (from to filename
+                                                       &optional
+                                                       visit beg end replace)
+  "Decode the region between FROM and TO as if it is read from file FILENAME.
+Optional arguments VISIT, BEG, END, and REPLACE are the same as those
+of the function `insert-file-contents'."
+  (save-excursion
+    (save-restriction
+      (narrow-to-region from to)
+      (goto-char (point-min))
+      (let ((coding coding-system-for-read))
+       (or coding
+           (setq coding (funcall set-auto-coding-function
+                                 filename (- (point-max) (point-min)))))
+       (or coding
+           (setq coding (find-operation-coding-system
+                         'insert-file-contents
+                         filename visit beg end replace)))
+       (if (coding-system-p coding)
+           (or enable-multibyte-characters
+               (setq coding
+                     (coding-system-change-text-conversion coding 'raw-text)))
+         (setq coding nil))
+       (if coding
+           (decode-coding-region (point-min) (point-max) coding))
+       (setq last-coding-system-used coding)))))
+
 (defun make-translation-table (&rest args)
   "Make a translation table from arguments.
 A translation table is a char table intended for character