Clean up logic surrounding file downloader matching

CHANGELOG.md

@@ -47,6 +47,7 @@
   - Add missing translation for "saving" state on VirtualBox. [GH-1110]
   - Proper error message if the remote end unexpectedly resets the connection
     while downloading a box over HTTP. [GH-1090]
+  - Allow "file://" URLs for box URLs. [GH-1087]
 
 ## 1.0.3 (May 1, 2012)
 

lib/vagrant/downloaders/file.rb

@@ -8,7 +8,13 @@ module Vagrant
     class File < Base
       def self.match?(uri)
         extracted = URI.extract(uri, "file")
-        (extracted && extracted.include?(uri)) || ::File.file?(::File.expand_path(uri))
+
+        # We match if we got a file URI. It doesn't matter here if the file
+        # doesn't exist because we check again later as well.
+        return true if extracted && extracted.include?(uri)
+
+        # Otherwise we match if the file exists
+        return ::File.file?(::File.expand_path(uri))
       end
 
       def download!(source_url, destination_file)