X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/919a07bb1d628890cbd729285d9b307bb9fe471f..3b7f63b13fde224c5b0cf76a9dea51e820f1d93e:/lisp/jka-compr.el

diff --git a/lisp/jka-compr.el b/lisp/jka-compr.el
index 5c139c865d..caa0711081 100644
--- a/lisp/jka-compr.el
+++ b/lisp/jka-compr.el
@@ -1,99 +1,128 @@
-;;; jka-compr.el - reading/writing/loading compressed files.
-;;; Copyright (C) 1993, 1994  Free Software Foundation, Inc.
+;;; jka-compr.el --- reading/writing/loading compressed files
+
+;; Copyright (C) 1993, 1994, 1995, 1997  Free Software Foundation, Inc.
 
 ;; Author: jka@ece.cmu.edu (Jay K. Adams)
+;; Maintainer: FSF
 ;; Keywords: data
 
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
 ;;; Commentary: 
 
-;;; This package implements low-level support for reading, writing,
-;;; and loading compressed files.  It hooks into the low-level file
-;;; I/O functions (including write-region and insert-file-contents) so
-;;; that they automatically compress or uncompress a file if the file
-;;; appears to need it (based on the extension of the file name).
-;;; Packages like Rmail, VM, GNUS, and Info should be able to work
-;;; with compressed files without modification.
-
-
-;;; INSTRUCTIONS:
-;;;
-;;; To use jka-compr, simply load this package, and edit as usual.
-;;; Its operation should be transparent to the user (except for
-;;; messages appearing when a file is being compressed or
-;;; uncompressed).
-;;;
-;;; The variable, jka-compr-compression-info-list can be used to
-;;; customize jka-compr to work with other compression programs.
-;;; The default value of this variable allows jka-compr to work with
-;;; Unix compress and gzip.
-;;;
-;;; If you are concerned about the stderr output of gzip and other
-;;; compression/decompression programs showing up in your buffers, you
-;;; should set the discard-error flag in the compression-info-list.
-;;; This will cause the stderr of all programs to be discarded.
-;;; However, it also causes emacs to call compression/uncompression
-;;; programs through a shell (which is specified by jka-compr-shell).
-;;; This may be a drag if, on your system, starting up a shell is
-;;; slow.
-;;;
-;;; If you don't want messages about compressing and decompressing
-;;; to show up in the echo area, you can set the compress-name and
-;;; decompress-name fields of the jka-compr-compression-info-list to
-;;; nil.
-
-
-;;; APPLICATION NOTES:
-;;;
-;;; crypt++
-;;;   jka-compr can coexist with crpyt++ if you take all the decompression
-;;;   entries out of the crypt-encoding-list.  Clearly problems will arise if
-;;;   you have two programs trying to compress/decompress files.  jka-compr
-;;;   will not "work with" crypt++ in the following sense: you won't be able to
-;;;   decode encrypted compressed files--that is, files that have been
-;;;   compressed then encrypted (in that order).  Theoretically, crypt++ and
-;;;   jka-compr could properly handle a file that has been encrypted then
-;;;   compressed, but there is little point in trying to compress an encrypted
-;;;   file.
-;;;
-
-
-;;; ACKNOWLEDGMENTS
-;;; 
-;;; jka-compr is a V19 adaptation of jka-compr for V18 of Emacs.  Many people
-;;; have made helpful suggestions, reported bugs, and even fixed bugs in 
-;;; jka-compr.  I recall the following people as being particularly helpful.
-;;;
-;;;   Jean-loup Gailly
-;;;   David Hughes
-;;;   Richard Pieri
-;;;   Daniel Quinlan
-;;;   Chris P. Ross
-;;;   Rick Sladkey
-;;;
-;;; Andy Norman's ange-ftp was the inspiration for the original jka-compr for
-;;; Version 18 of Emacs.
-;;;
-;;; After I had made progress on the original jka-compr for V18, I learned of a
-;;; package written by Kazushi Jam Marukawa, called jam-zcat, that did exactly
-;;; what I was trying to do.  I looked over the jam-zcat source code and
-;;; probably got some ideas from it.
-;;;
+;; This package implements low-level support for reading, writing,
+;; and loading compressed files.  It hooks into the low-level file
+;; I/O functions (including write-region and insert-file-contents) so
+;; that they automatically compress or uncompress a file if the file
+;; appears to need it (based on the extension of the file name).
+;; Packages like Rmail, VM, GNUS, and Info should be able to work
+;; with compressed files without modification.
+
+
+;; INSTRUCTIONS:
+;;
+;; To use jka-compr, simply load this package, and edit as usual.
+;; Its operation should be transparent to the user (except for
+;; messages appearing when a file is being compressed or
+;; uncompressed).
+;;
+;; The variable, jka-compr-compression-info-list can be used to
+;; customize jka-compr to work with other compression programs.
+;; The default value of this variable allows jka-compr to work with
+;; Unix compress and gzip.
+;;
+;; If you are concerned about the stderr output of gzip and other
+;; compression/decompression programs showing up in your buffers, you
+;; should set the discard-error flag in the compression-info-list.
+;; This will cause the stderr of all programs to be discarded.
+;; However, it also causes emacs to call compression/uncompression
+;; programs through a shell (which is specified by jka-compr-shell).
+;; This may be a drag if, on your system, starting up a shell is
+;; slow.
+;;
+;; If you don't want messages about compressing and decompressing
+;; to show up in the echo area, you can set the compress-name and
+;; decompress-name fields of the jka-compr-compression-info-list to
+;; nil.
+
+
+;; APPLICATION NOTES:
+;;
+;; crypt++
+;;   jka-compr can coexist with crpyt++ if you take all the decompression
+;;   entries out of the crypt-encoding-list.  Clearly problems will arise if
+;;   you have two programs trying to compress/decompress files.  jka-compr
+;;   will not "work with" crypt++ in the following sense: you won't be able to
+;;   decode encrypted compressed files--that is, files that have been
+;;   compressed then encrypted (in that order).  Theoretically, crypt++ and
+;;   jka-compr could properly handle a file that has been encrypted then
+;;   compressed, but there is little point in trying to compress an encrypted
+;;   file.
+;;
+
+
+;; ACKNOWLEDGMENTS
+;; 
+;; jka-compr is a V19 adaptation of jka-compr for V18 of Emacs.  Many people
+;; have made helpful suggestions, reported bugs, and even fixed bugs in 
+;; jka-compr.  I recall the following people as being particularly helpful.
+;;
+;;   Jean-loup Gailly
+;;   David Hughes
+;;   Richard Pieri
+;;   Daniel Quinlan
+;;   Chris P. Ross
+;;   Rick Sladkey
+;;
+;; Andy Norman's ange-ftp was the inspiration for the original jka-compr for
+;; Version 18 of Emacs.
+;;
+;; After I had made progress on the original jka-compr for V18, I learned of a
+;; package written by Kazushi Jam Marukawa, called jam-zcat, that did exactly
+;; what I was trying to do.  I looked over the jam-zcat source code and
+;; probably got some ideas from it.
+;;
 
 ;;; Code:
 
-(defvar jka-compr-shell "sh"
+(defgroup compression nil
+  "Data compression utilities"
+  :group 'data)
+
+(defgroup jka-compr nil
+  "jka-compr customization"
+  :group 'compression)
+
+
+(defcustom jka-compr-shell "sh"
   "*Shell to be used for calling compression programs.
 The value of this variable only matters if you want to discard the
 stderr of a compression/decompression program (see the documentation
-for `jka-compr-compression-info-list').")
-
-
-(defvar jka-compr-use-shell t)
+for `jka-compr-compression-info-list')."
+  :type 'string
+  :group 'jka-compr)
 
+(defvar jka-compr-use-shell 
+  (not (memq system-type '(ms-dos windows-nt))))
 
 ;;; I have this defined so that .Z files are assumed to be in unix
-;;; compress format; and .gz files, in gzip format.
-(defvar jka-compr-compression-info-list
+;;; compress format; and .gz files, in gzip format, and .bz2 files in bzip fmt.
+(defcustom jka-compr-compression-info-list
   ;;[regexp
   ;; compr-message  compr-prog  compr-args
   ;; uncomp-message uncomp-prog uncomp-args
@@ -102,6 +131,13 @@ for `jka-compr-compression-info-list').")
      "compressing"    "compress"     ("-c")
      "uncompressing"  "uncompress"   ("-c")
      nil t]
+     ;; Formerly, these had an additional arg "-c", but that fails with
+     ;; "Version 0.1pl2, 29-Aug-97." (RedHat 5.1 GNU/Linux) and
+     ;; "Version 0.9.0b, 9-Sept-98".
+    ["\\.bz2\\'"
+     "bzip2ing"        "bzip2"         nil
+     "bunzip2ing"      "bzip2"         ("-d")
+     nil t]
     ["\\.tgz\\'"
      "zipping"        "gzip"         ("-c" "-q")
      "unzipping"      "gzip"         ("-c" "-q" "-d")
@@ -142,17 +178,34 @@ APPEND-FLAG EXTENSION], where:
 
 Because of the way `call-process' is defined, discarding the stderr output of
 a program adds the overhead of starting a shell each time the program is
-invoked.")
+invoked."
+  :type '(repeat (vector regexp
+			 (choice :tag "Compress Message"
+				 (string :format "%v")
+				 (const :tag "No Message" nil))
+			 (string :tag "Compress Program")
+			 (repeat :tag "Compress Arguments" string)
+			 (choice :tag "Uncompress Message"
+				 (string :format "%v")
+				 (const :tag "No Message" nil))
+			 (string :tag "Uncompress Program")
+			 (repeat :tag "Uncompress Arguments" string)
+			 (boolean :tag "Append")
+			 (boolean :tag "Auto Mode")))
+  :group 'jka-compr)
 
 (defvar jka-compr-mode-alist-additions
   (list (cons "\\.tgz\\'" 'tar-mode))
-  "A list of pairs to add to auto-mode-alist when jka-compr is installed.")
+  "A list of pairs to add to `auto-mode-alist' when jka-compr is installed.")
+
+;; List of all the elements we actually added to file-coding-system-alist.
+(defvar jka-compr-added-to-file-coding-system-alist nil)
 
 (defvar jka-compr-file-name-handler-entry
   nil
   "The entry in `file-name-handler-alist' used by the jka-compr I/O functions.")
 
-;;; Functions for accessing the return value of jka-get-compression-info
+;;; Functions for accessing the return value of jka-compr-get-compression-info
 (defun jka-compr-info-regexp               (info)  (aref info 0))
 (defun jka-compr-info-compress-message     (info)  (aref info 1))
 (defun jka-compr-info-compress-program     (info)  (aref info 2))
@@ -181,27 +234,26 @@ based on the filename itself and `jka-compr-compression-info-list'."
 (put 'compression-error 'error-conditions '(compression-error file-error error))
 
 
-(defvar jka-compr-acceptable-retval-list '(0 141))
+(defvar jka-compr-acceptable-retval-list '(0 2 141))
 
 
 (defun jka-compr-error (prog args infile message &optional errfile)
 
   (let ((errbuf (get-buffer-create " *jka-compr-error*"))
 	(curbuf (current-buffer)))
-    (set-buffer errbuf)
-    (widen) (erase-buffer)
-    (insert (format "Error while executing \"%s %s < %s\"\n\n"
-		     prog
-		     (mapconcat 'identity args " ")
-		     infile))
-
-     (and errfile
-	  (insert-file-contents errfile))
-
-     (set-buffer curbuf)
+    (with-current-buffer errbuf
+      (widen) (erase-buffer)
+      (insert (format "Error while executing \"%s %s < %s\"\n\n"
+		      prog
+		      (mapconcat 'identity args " ")
+		      infile))
+
+      (and errfile
+	   (insert-file-contents errfile)))
      (display-buffer errbuf))
 
-  (signal 'compression-error (list "Opening input file" (format "error %s" message) infile)))
+  (signal 'compression-error
+	  (list "Opening input file" (format "error %s" message) infile)))
 			
    
 (defvar jka-compr-dd-program
@@ -255,8 +307,10 @@ to keep: LEN chars starting BEG chars from the beginning."
 (defun jka-compr-call-process (prog message infile output temp args)
   (if jka-compr-use-shell
 
-      (let ((err-file (jka-compr-make-temp-name)))
-	    
+      (let ((err-file (jka-compr-make-temp-name))
+	    (coding-system-for-read (or coding-system-for-read 'undecided))
+            (coding-system-for-write 'no-conversion))
+
 	(unwind-protect
 
 	    (or (memq
@@ -287,20 +341,20 @@ to keep: LEN chars starting BEG chars from the beginning."
 	(jka-compr-error prog args infile message))
 
     (and (stringp output)
-	 (let ((cbuf (current-buffer)))
-	   (set-buffer temp)
+	 (with-current-buffer temp
 	   (write-region (point-min) (point-max) output)
-	   (erase-buffer)
-	   (set-buffer cbuf)))))
+	   (erase-buffer)))))
 
 
 ;;; Support for temp files.  Much of this was inspired if not lifted
 ;;; from ange-ftp.
 
-(defvar jka-compr-temp-name-template
-  "/tmp/jka-com"
+(defcustom jka-compr-temp-name-template
+  (expand-file-name "jka-com" temporary-file-directory)
   "Prefix added to all temp files created by jka-compr.
-There should be no more than seven characters after the final `/'")
+There should be no more than seven characters after the final `/'."
+  :type 'string
+  :group 'jka-compr)
 
 (defvar jka-compr-temp-name-table (make-vector 31 nil))
 
@@ -361,68 +415,57 @@ There should be no more than seven characters after the final `/'")
 		(uncompress-message (jka-compr-info-uncompress-message info))
 		(compress-args (jka-compr-info-compress-args info))
 		(uncompress-args (jka-compr-info-uncompress-args info))
-		(temp-file (jka-compr-make-temp-name))
 		(base-name (file-name-nondirectory visit-file))
-		cbuf temp-buffer)
-
-	    (setq cbuf (current-buffer)
-		  temp-buffer (get-buffer-create " *jka-compr-temp*"))
-	    (set-buffer temp-buffer)
-	    (widen) (erase-buffer)
-	    (set-buffer cbuf)
-
-	    (and append
-		 (not can-append)
-		 (file-exists-p filename)
-		 (let* ((local-copy (file-local-copy filename))
-			(local-file (or local-copy filename)))
-
-		   (unwind-protect
-
-		       (progn
-		      
-			 (and
-			  uncompress-message
-			  (message "%s %s..." uncompress-message base-name))
-
-			 (jka-compr-call-process uncompress-program
-						 (concat uncompress-message
-							 " " base-name)
-						 local-file
-						 temp-file
-						 temp-buffer
-						 uncompress-args)
-			 (and
-			  uncompress-message
-			  (message "%s %s...done" uncompress-message base-name)))
-		     
-		     (and
-		      local-copy
-		      (file-exists-p local-copy)
-		      (delete-file local-copy)))))
+		temp-file temp-buffer
+		;; we need to leave `last-coding-system-used' set to its
+		;; value after calling write-region the first time, so
+		;; that `basic-save-buffer' sees the right value.
+		(coding-system-used last-coding-system-used))
+
+	    (setq temp-buffer (get-buffer-create " *jka-compr-wr-temp*"))
+	    (with-current-buffer temp-buffer
+	      (widen) (erase-buffer))
+
+	    (if (and append
+		     (not can-append)
+		     (file-exists-p filename))
+		
+		(let* ((local-copy (file-local-copy filename))
+		       (local-file (or local-copy filename)))
+		  
+		  (setq temp-file local-file))
+
+	      (setq temp-file (jka-compr-make-temp-name)))
 
 	    (and 
 	     compress-message
 	     (message "%s %s..." compress-message base-name))
-
+	    
 	    (jka-compr-run-real-handler 'write-region
 					(list start end temp-file t 'dont))
-
-	    (jka-compr-call-process compress-program
-				    (concat compress-message
-					    " " base-name)
-				    temp-file
-				    temp-buffer
-				    nil
-				    compress-args)
-
-	    (set-buffer temp-buffer)
-	    (jka-compr-run-real-handler 'write-region
-					(list (point-min) (point-max)
-					      filename
-					      (and append can-append) 'dont))
-	    (erase-buffer)
-	    (set-buffer cbuf)
+	    ;; save value used by the real write-region
+	    (setq coding-system-used last-coding-system-used)
+
+	    ;; Here we must read the output of compress program as is
+	    ;; without any code conversion.
+	    (let ((coding-system-for-read 'no-conversion))
+	      (jka-compr-call-process compress-program
+				      (concat compress-message
+					      " " base-name)
+				      temp-file
+				      temp-buffer
+				      nil
+				      compress-args))
+
+	    (with-current-buffer temp-buffer
+              (let ((coding-system-for-write 'no-conversion))
+                (if (memq system-type '(ms-dos windows-nt))
+                    (setq buffer-file-type t) )
+                (jka-compr-run-real-handler 'write-region
+                                            (list (point-min) (point-max)
+                                                  filename
+                                                  (and append can-append) 'dont))
+                (erase-buffer)) )
 
 	    (jka-compr-delete-temp-file temp-file)
 
@@ -444,6 +487,9 @@ There should be no more than seven characters after the final `/'")
 		     (stringp visit))
 		 (message "Wrote %s" visit-file))
 
+	    ;; ensure `last-coding-system-used' has an appropriate value
+	    (setq last-coding-system-used coding-system-used)
+
 	    nil)
 	      
 	(jka-compr-run-real-handler 'write-region
@@ -470,7 +516,18 @@ There should be no more than seven characters after the final `/'")
 	      (local-copy
 	       (jka-compr-run-real-handler 'file-local-copy (list filename)))
 	      local-file
-	      size start)
+	      size start
+              (coding-system-for-read
+	       (or coding-system-for-read
+		   ;; If multibyte characters are disabled,
+		   ;; don't do that conversion.
+		   (and (null enable-multibyte-characters)
+			'raw-text)
+		   (let ((coding (find-operation-coding-system
+				  'insert-file-contents
+				  (jka-compr-byte-compiler-base-file-name file))))
+		     (and (consp coding) (car coding)))
+		   'undecided)) )
 
 	  (setq local-file (or local-copy filename))
 
@@ -502,13 +559,18 @@ There should be no more than seven characters after the final `/'")
 							(if (and beg end)
 							    (- end beg)
 							  end))
-			(jka-compr-call-process uncompress-program
-						(concat uncompress-message
-							" " base-name)
-						local-file
-						t
-						nil
-						uncompress-args))
+			;; If visiting, bind off buffer-file-name so that
+			;; file-locking will not ask whether we should
+			;; really edit the buffer.
+			(let ((buffer-file-name
+			       (if visit nil buffer-file-name)))
+			  (jka-compr-call-process uncompress-program
+						  (concat uncompress-message
+							  " " base-name)
+						  local-file
+						  t
+						  nil
+						  uncompress-args)))
 		      (setq size (- (point) start))
 		      (if replace
 			  (let* ((del-beg (point))
@@ -548,18 +610,22 @@ There should be no more than seven characters after the final `/'")
 	   (signal 'file-error
 		   (cons "Opening input file" (nth 2 notfound))))
 
-	  ;; Run the functions that insert-file-contents would.
-	  (let ((p after-insert-file-functions)
-		(insval size))
-	    (while p
-	      (setq insval (funcall (car p) size))
-	      (if insval
-		  (progn
-		    (or (integerp insval)
-			(signal 'wrong-type-argument
-				(list 'integerp insval)))
-		    (setq size insval)))
-	      (setq p (cdr p))))
+	  ;; This is done in insert-file-contents after we return.
+	  ;; That is a little weird, but better to go along with it now
+	  ;; than to change it now.
+
+;;;	  ;; Run the functions that insert-file-contents would.
+;;; 	  (let ((p after-insert-file-functions)
+;;; 		(insval size))
+;;; 	    (while p
+;;; 	      (setq insval (funcall (car p) size))
+;;; 	      (if insval
+;;; 		  (progn
+;;; 		    (or (integerp insval)
+;;; 			(signal 'wrong-type-argument
+;;; 				(list 'integerp insval)))
+;;; 		    (setq size insval)))
+;;; 	      (setq p (cdr p))))
 
 	  (list filename size))
 
@@ -580,44 +646,48 @@ There should be no more than seven characters after the final `/'")
 	      (local-copy
 	       (jka-compr-run-real-handler 'file-local-copy (list filename)))
 	      (temp-file (jka-compr-make-temp-name t))
-	      (temp-buffer (get-buffer-create " *jka-compr-temp*"))
+	      (temp-buffer (get-buffer-create " *jka-compr-flc-temp*"))
 	      (notfound nil)
-	      (cbuf (current-buffer))
 	      local-file)
 
 	  (setq local-file (or local-copy filename))
 
 	  (unwind-protect
 
-	      (progn
+	      (with-current-buffer temp-buffer
 		  
 		(and
 		 uncompress-message
 		 (message "%s %s..." uncompress-message base-name))
-
-		(set-buffer temp-buffer)
 		  
-		(jka-compr-call-process uncompress-program
-					(concat uncompress-message
-						" " base-name)
-					local-file
-					t
-					nil
-					uncompress-args)
-
-		(and
-		 uncompress-message
-		 (message "%s %s...done" uncompress-message base-name))
-
-		(write-region
-		 (point-min) (point-max) temp-file nil 'dont))
+		;; Here we must read the output of uncompress program
+		;; and write it to TEMP-FILE without any code
+		;; conversion.  An appropriate code conversion (if
+		;; necessary) is done by the later I/O operation
+		;; (e.g. load).
+		(let ((coding-system-for-read 'no-conversion)
+		      (coding-system-for-write 'no-conversion))
+
+		  (jka-compr-call-process uncompress-program
+					  (concat uncompress-message
+						  " " base-name)
+					  local-file
+					  t
+					  nil
+					  uncompress-args)
+
+		  (and
+		   uncompress-message
+		   (message "%s %s...done" uncompress-message base-name))
+
+		  (write-region
+		   (point-min) (point-max) temp-file nil 'dont)))
 
 	    (and
 	     local-copy
 	     (file-exists-p local-copy)
 	     (delete-file local-copy))
 
-	    (set-buffer cbuf)
 	    (kill-buffer temp-buffer))
 
 	  temp-file)
@@ -639,7 +709,8 @@ There should be no more than seven characters after the final `/'")
 	  (or nomessage
 	      (message "Loading %s..." file))
 
-	  (load load-file noerror t t)
+	  (let ((load-force-doc-strings t))
+	    (load load-file noerror t t))
 
 	  (or nomessage
 	      (message "Loading %s...done." file)))
@@ -647,16 +718,30 @@ There should be no more than seven characters after the final `/'")
       (jka-compr-delete-temp-file local-copy))
 
     t))
+
+(defun jka-compr-byte-compiler-base-file-name (file)
+  (let ((info (jka-compr-get-compression-info file)))
+    (if (and info (jka-compr-info-strip-extension info))
+	(save-match-data
+	  (substring file 0 (string-match (jka-compr-info-regexp info) file)))
+      file)))
 
 (put 'write-region 'jka-compr 'jka-compr-write-region)
 (put 'insert-file-contents 'jka-compr 'jka-compr-insert-file-contents)
 (put 'file-local-copy 'jka-compr 'jka-compr-file-local-copy)
 (put 'load 'jka-compr 'jka-compr-load)
+(put 'byte-compiler-base-file-name 'jka-compr
+     'jka-compr-byte-compiler-base-file-name)
+
+(defvar jka-compr-inhibit nil
+  "Non-nil means inhibit automatic uncompression temporarily.
+Lisp programs can bind this to t to do that.
+It is not recommended to set this variable permanently to anything but nil.")
 
 (defun jka-compr-handler (operation &rest args)
   (save-match-data
     (let ((jka-op (get operation 'jka-compr)))
-      (if jka-op
+      (if (and jka-op (not jka-compr-inhibit))
 	  (apply jka-op args)
 	(jka-compr-run-real-handler operation args)))))
 
@@ -672,11 +757,26 @@ There should be no more than seven characters after the final `/'")
 	(inhibit-file-name-operation operation))
     (apply operation args)))
 
-(defun toggle-auto-compression (arg)
-  "Toggle automatic file compression and decompression.
+;;;###autoload(defun auto-compression-mode (&optional arg)
+;;;###autoload  "\
+;;;###autoloadToggle automatic file compression and uncompression.
+;;;###autoloadWith prefix argument ARG, turn auto compression on if positive, else off.
+;;;###autoloadReturns the new status of auto compression (non-nil means on)."
+;;;###autoload  (interactive "P")
+;;;###autoload  (if (not (fboundp 'jka-compr-installed-p))
+;;;###autoload      (progn
+;;;###autoload        (require 'jka-compr)
+;;;###autoload        ;; That turned the mode on, so make it initially off.
+;;;###autoload        (toggle-auto-compression)))
+;;;###autoload  (toggle-auto-compression arg t))
+
+(defun toggle-auto-compression (&optional arg message)
+  "Toggle automatic file compression and uncompression.
 With prefix argument ARG, turn auto compression on if positive, else off.
-Returns the new status of auto compression (non-nil means on)."
-  (interactive "P")
+Returns the new status of auto compression (non-nil means on).
+If the argument MESSAGE is non-nil, it means to print a message
+saying whether the mode is now on or off."
+  (interactive "P\np")
   (let* ((installed (jka-compr-installed-p))
 	 (flag (if (null arg)
 		   (not installed)
@@ -694,14 +794,13 @@ Returns the new status of auto compression (non-nil means on)."
       (jka-compr-uninstall)))
 
 
-    (and (interactive-p)
+    (and message
 	 (if flag
 	     (message "Automatic file (de)compression is now ON.")
 	   (message "Automatic file (de)compression is now OFF.")))
 
     flag))
 
-
 (defun jka-compr-build-file-regexp ()
   (concat
    "\\("
@@ -723,8 +822,18 @@ and `inhibit-first-line-modes-suffixes'."
   (setq file-name-handler-alist (cons jka-compr-file-name-handler-entry
 				      file-name-handler-alist))
 
+  (setq jka-compr-added-to-file-coding-system-alist nil)
+
   (mapcar
    (function (lambda (x)
+	       ;; Don't do multibyte encoding on the compressed files.
+	       (let ((elt (cons (jka-compr-info-regexp x)
+				 '(no-conversion . no-conversion))))
+		 (setq file-coding-system-alist
+		       (cons elt file-coding-system-alist))
+		 (setq jka-compr-added-to-file-coding-system-alist
+		       (cons elt jka-compr-added-to-file-coding-system-alist)))
+
 	       (and (jka-compr-info-strip-extension x)
 		    ;; Make entries in auto-mode-alist so that modes
 		    ;; are chosen right according to the file names
@@ -782,7 +891,19 @@ by `jka-compr-installed'."
 	  (setcdr last (cdr (cdr last)))
 	(setq last (cdr last))))
     
-    (setq auto-mode-alist (cdr ama))))
+    (setq auto-mode-alist (cdr ama)))
+
+  (let* ((ama (cons nil file-coding-system-alist))
+	 (last ama)
+	 entry)
+
+    (while (cdr last)
+      (setq entry (car (cdr last)))
+      (if (member entry jka-compr-added-to-file-coding-system-alist)
+	  (setcdr last (cdr (cdr last)))
+	(setq last (cdr last))))
+    
+    (setq file-coding-system-alist (cdr ama))))
 
       
 (defun jka-compr-installed-p ()