(set-auto-coding-for-load): New variable.

(set-auto-coding): If set-auto-coding-for-load is non-nil,
look for "unibyte" file variable first, then for "coding".
(load-with-code-conversion): Bind set-auto-coding-for-load to t.

1 files changed, 40 insertions, 18 deletions

diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index 923ff1178fb..bb05a12bbc1 100644
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -64,6 +64,7 @@ Return t if file exists."
         (setq preloaded-file-list (cons file preloaded-file-list)))
       (unwind-protect
           (let ((load-file-name fullname)
+                (set-auto-coding-for-load t)
                 (inhibit-file-name-operation nil))
             (save-excursion
               (set-buffer buffer)
@@ -774,12 +775,18 @@ LIST is a list of coding categories ordered by priority."
 
 ;;; FILE I/O
 
+(defvar set-auto-coding-for-load nil
+  "Non-nil means look for `load-coding' property instead of `coding'.
+This is used for loading and byte-compiling Emacs Lisp files.")
+
 (defun set-auto-coding (size)
   "Return coding system for a file of which SIZE bytes follow point.
+These bytes should include at least the first 1k of the file
+and the last 3k of the file, but the middle may be omitted.
 
-It checks for a -*- coding: tag in the first one or two lines
-following point.  If no coding: tag is found, it checks local
-variables spec in the last 3K-byte of SIZE bytes.
+It checks for a `coding:' tag in the first one or two lines following
+point.  If no `coding:' tag is found, it checks for alocal variables
+list in the last 3K bytes out of the SIZE bytes.
 
 The return value is the specified coding system,
 or nil if nothing specified.
@@ -792,14 +799,16 @@ function by default."
          (tail-start (+ head-start (max (- size 3072) 0)))
          (tail-end (+ head-start size))
          coding-system head-found tail-found pos)
-    ;; Try a short cut by searching for the string "coding:" at the
-    ;; head and tail of SIZE bytes.
-    (setq head-found (search-forward "coding:" head-end t))
+    ;; Try a short cut by searching for the string "coding:"
+    ;; and for "unibyte:" at th ehead and tail of SIZE bytes.
+    (setq head-found (or (search-forward "coding:" head-end t)
+                         (search-forward "unibyte:" head-end t)))
     (if (and head-found (> head-found tail-start))
         ;; Head and tail are overlapped.
         (setq tail-found head-found)
       (goto-char tail-start)
-      (setq tail-found (search-forward "coding:" tail-end t)))
+      (setq tail-found (or (search-forward "coding:" tail-end t)
+                           (search-forward "unibyte:" tail-end t))))
 
     ;; At first check the head.
     (when head-found
@@ -816,12 +825,18 @@ function by default."
       (if pos (setq head-end pos))
       (when (< head-found head-end)
         (goto-char head-start)
-        (if (re-search-forward
-             "-\\*-\\(.*;\\)?[ \t]*coding:[ \t]*\\([^ ;]+\\)" head-end t)
-            (progn
-              (setq coding-system (intern (match-string 2)))
-              (or (coding-system-p coding-system)
-                  (setq coding-system nil))))))
+        (when (and set-auto-coding-for-load
+                   (re-search-forward
+                    "-\\*-\\(.*;\\)?[ \t]*unibyte:[ \t]*\\([^ ;]+\\)"
+                    head-end t))
+          (setq coding-system 'raw-text))
+        (when (and (not coding-system)
+                   (re-search-forward
+                    "-\\*-\\(.*;\\)?[ \t]*coding:[ \t]*\\([^ ;]+\\)"
+                    head-end t))
+          (setq coding-system (intern (match-string 2)))
+          (or (coding-system-p coding-system)
+              (setq coding-system nil)))))
 
     ;; If no coding: tag in the head, check the tail.
     (when (and tail-found (not coding-system))
@@ -838,17 +853,24 @@ function by default."
                              "^" prefix
                              "coding[ \t]*:[ \t]*\\([^ \t]+\\)[ \t]*"
                              suffix "$"))
+                 (re-unibyte (concat
+                              "^" prefix
+                              "unibyte[ \t]*:[ \t]*\\([^ \t]+\\)[ \t]*"
+                              suffix "$"))
                  (re-end (concat
                           "^" prefix "end *:[ \t]*" suffix "$"))
                  (pos (point)))
             (re-search-forward re-end tail-end 'move)
             (setq tail-end (point))
             (goto-char pos)
-            (if (re-search-forward re-coding tail-end t)
-                (progn
-                  (setq coding-system (intern (match-string 1)))
-                  (or (coding-system-p coding-system)
-                      (setq coding-system nil)))))))
+            (when (and set-auto-coding-for-load
+                       (re-search-forward re-unibyte tail-end t))
+              (setq coding-system 'raw-text))
+            (when (and (not coding-system)
+                       (re-search-forward re-coding tail-end t))
+              (setq coding-system (intern (match-string 1)))
+              (or (coding-system-p coding-system)
+                  (setq coding-system nil))))))
     coding-system))
 
 (setq set-auto-coding-function 'set-auto-coding)