(byte-compile-current-file): Don't bind

it, so that a boundp test can be used to determine if we're
currently byte-compiling.

lisp/emacs-lisp/bytecomp.el

@@ -10,7 +10,7 @@
 
 ;;; This version incorporates changes up to version 2.10 of the
 ;;; Zawinski-Furuseth compiler.
-(defconst byte-compile-version "$Revision: 2.78 $")
+(defconst byte-compile-version "$Revision: 2.79.1.1 $")
 
 ;; This file is part of GNU Emacs.
 
@@ -792,9 +792,11 @@ Each function's symbol gets marked with the `byte-compile-noruntime' property."
 ;;; byte compiler messages
 
 (defvar byte-compile-current-form nil)
-(defvar byte-compile-current-file nil)
 (defvar byte-compile-dest-file nil)
 
+;; Don't actually bind this.
+(defvar byte-compile-current-file)
+
 (defmacro byte-compile-log (format-string &rest args)
   (list 'and
 	'byte-optimize