Subject: bug#11585: 24.0.50; corrupted byte compiled files

From: Stefan Monnier <[email-masked]>
Date: Wed, 30 May 2012 11:24:49 -0400

> Certain of my .el files are incorrectly compiled. See the .elc
> file with a long name.

Duh, indeed it was byte-compile-fix-header, thanks for investigating.
I think your patch has the problem that it changes the byte-position of
the text in the rest of the buffer, which will break lazy-loaded
docstrings and byte-code.
Can you try the patch below instead, which will simply report the actual
load-file-name rather than file name of the source.

        Stefan

=== modified file 'lisp/emacs-lisp/bytecomp.el'
--- lisp/emacs-lisp/bytecomp.el	2012-05-30 03:59:42 +0000
+++ lisp/emacs-lisp/bytecomp.el	2012-05-30 15:18:29 +0000
@@ -1937,7 +1937,7 @@
 	     (byte-compile-fix-header byte-compile-current-file))))
      byte-compile--outbuffer)))
 
-(defun byte-compile-fix-header (filename)
+(defun byte-compile-fix-header (_filename)
   "If the current buffer has any multibyte characters, insert a version test."
   (when (< (point-max) (position-bytes (point-max)))
     (goto-char (point-min))
@@ -1962,11 +1962,8 @@
        ;; don't try to check the version number.
        "     (< (aref emacs-version (1- (length emacs-version))) ?A)\n"
        (format "     (string-lessp emacs-version \"%s\")\n" minimum-version)
-       "     (error \"`"
-       ;; prin1-to-string is used to quote backslashes.
-       (substring (prin1-to-string (file-name-nondirectory filename))
-		  1 -1)
-       (format "' was compiled for Emacs %s or later\"))\n\n"
+       "     (error \"`%s"
+       (format "' was compiled for Emacs %s or later\" #$))\n\n"
 	       minimum-version))
       ;; Now compensate for any change in size, to make sure all
       ;; positions in the file remain valid.
@@ -2037,7 +2034,7 @@
         (print-gensym t)
         (print-circle                   ; Handle circular data structures.
          (not byte-compile-disable-print-circle)))
-    (if (and (memq (car-safe form) '(defun defmacro defvar defvaralias defconst
+    (if (and (memq (car-safe form) '(defvar defvaralias defconst
                                       autoload custom-declare-variable))
              (stringp (nth 3 form)))
         (byte-compile-output-docform nil nil '("\n(" 3 ")") form nil