Update Tap for alias_path

Library/Homebrew/tab.rb

@@ -56,6 +56,10 @@ class Tab < OpenStruct
     attributes["source_modified_time"] ||= 0
     attributes["source"] ||= {}
 
+    if alias_path = attributes["alias_path"]
+      attributes["alias_path"] = Pathname.new(alias_path)
+    end
+
     tapped_from = attributes["tapped_from"]
     unless tapped_from.nil? || tapped_from == "path or URL"
       attributes["source"]["tap"] = attributes.delete("tapped_from")
@@ -294,7 +298,7 @@ class Tab < OpenStruct
       "time" => time,
       "source_modified_time" => source_modified_time.to_i,
       "HEAD" => self.HEAD,
-      "alias_path" => alias_path,
+      "alias_path" => alias_path && alias_path.to_s,
       "stdlib" => (stdlib.to_s if stdlib),
       "compiler" => (compiler.to_s if compiler),
       "source" => source

Library/Homebrew/test/fixtures/receipt.json

@@ -11,7 +11,7 @@
   "poured_from_bottle": true,
   "time": 1403827774,
   "HEAD": "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef",
-  "alias_path": "test-formula",
+  "alias_path": "/usr/local/Library/Taps/homebrew/homebrew-core/Aliases/test-formula",
   "stdlib": "libcxx",
   "compiler": "clang",
   "source": {

Library/Homebrew/test/test_tab.rb

@@ -100,6 +100,7 @@ class TabTests < Homebrew::TestCase
   def test_from_file
     path = Pathname.new(TEST_DIRECTORY).join("fixtures", "receipt.json")
     tab = Tab.from_file(path)
+    alias_path = Pathname.new("/usr/local/Library/Taps/homebrew/homebrew-core/Aliases/test-formula")
 
     assert_equal @used.sort, tab.used_options.sort
     assert_equal @unused.sort, tab.unused_options.sort
@@ -117,7 +118,7 @@ class TabTests < Homebrew::TestCase
     assert_equal "2.14", tab.stable_version.to_s
     assert_equal "2.15", tab.devel_version.to_s
     assert_equal "HEAD-0000000", tab.head_version.to_s
-    assert_equal "test-formula", tab.alias_path
+    assert_equal alias_path, tab.alias_path
   end
 
   def test_to_json