info: output correct URL for tapped dupes

Tapped formulae that dupe those in core now display the correct URL when
invoked like `brew info homebrew/dupes/openssl`.

This also fixes the broken `brew info` test.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/cmd/info.rb

@@ -28,8 +28,8 @@ module Homebrew extend self
     end
   end
 
-  def github_info name
-    path = Formula.path(name).realpath
+  def github_info f
+    path = f.path.realpath
 
     if path.to_s =~ %r{#{HOMEBREW_REPOSITORY}/Library/Taps/(\w+)-(\w+)/(.*)}
       user = $1
@@ -47,7 +47,7 @@ module Homebrew extend self
   end
 
   def info_formula f
-    exec 'open', github_info(f.name) if ARGV.flag? '--github'
+    exec 'open', github_info(f) if ARGV.flag? '--github'
 
     puts "#{f.name} #{f.version}"
     puts f.homepage
@@ -77,7 +77,7 @@ module Homebrew extend self
       puts "Not installed"
     end
 
-    history = github_info f.name
+    history = github_info(f)
     puts history if history
 
     the_caveats = (f.caveats || "").strip

Library/Homebrew/test/testball.rb

@@ -6,6 +6,7 @@ class TestBall <Formula
     @url="file:///#{TEST_FOLDER}/tarballs/testball-0.1.tbz"
     @homepage = 'http://example.com/'
     super "testball"
+    @path = Pathname.new(__FILE__)
   end
   def install
     prefix.install "bin"