src/Pure/General/sha1.scala

--- a/src/Pure/General/sha1.scala	Fri Jul 20 21:05:47 2012 +0200
+++ b/src/Pure/General/sha1.scala	Fri Jul 20 22:29:25 2012 +0200
@@ -8,7 +8,7 @@
 package isabelle
 
 
-import java.io.{File, FileInputStream}
+import java.io.{File => JFile, FileInputStream}
 import java.security.MessageDigest
 
 
@@ -30,7 +30,7 @@
     Digest(result.toString)
   }
 
-  def digest(file: File): Digest =
+  def digest(file: JFile): Digest =
   {
     val stream = new FileInputStream(file)
     val digest = MessageDigest.getInstance("SHA")