Use GitRepositoryExtension for HOMEBREW_REPOSITORY

Library/Homebrew/diagnostic.rb

@@ -805,7 +805,7 @@ module Homebrew
       def check_git_origin
         return if !Utils.git_available? || !(HOMEBREW_REPOSITORY/".git").exist?
 
-        origin = Homebrew.git_origin
+        origin = HOMEBREW_REPOSITORY.git_origin
 
         if origin.nil?
           <<-EOS.undent

Library/Homebrew/formula_installer.rb

@@ -761,7 +761,7 @@ class FormulaInstaller
     tab.tap = formula.tap
     tab.poured_from_bottle = true
     tab.time = Time.now.to_i
-    tab.head = Homebrew.git_head
+    tab.head = HOMEBREW_REPOSITORY.git_head
     tab.write
   end
 

Library/Homebrew/global.rb

@@ -20,6 +20,8 @@ HOMEBREW_WWW = "http://brew.sh"
 
 require "config"
 
+HOMEBREW_REPOSITORY.extend(GitRepositoryExtension)
+
 if RbConfig.respond_to?(:ruby)
   RUBY_PATH = Pathname.new(RbConfig.ruby)
 else

Library/Homebrew/system_config.rb

@@ -23,15 +23,15 @@ class SystemConfig
     end
 
     def head
-      Homebrew.git_head || "(none)"
+      HOMEBREW_REPOSITORY.git_head || "(none)"
     end
 
     def last_commit
-      Homebrew.git_last_commit || "never"
+      HOMEBREW_REPOSITORY.git_last_commit || "never"
     end
 
     def origin
-      Homebrew.git_origin || "(none)"
+      HOMEBREW_REPOSITORY.git_origin || "(none)"
     end
 
     def core_tap_head

Library/Homebrew/tab.rb

@@ -24,7 +24,7 @@ class Tab < OpenStruct
       "poured_from_bottle" => false,
       "time" => Time.now.to_i,
       "source_modified_time" => source_modified_time.to_i,
-      "HEAD" => Homebrew.git_head,
+      "HEAD" => HOMEBREW_REPOSITORY.git_head,
       "compiler" => compiler,
       "stdlib" => stdlib,
       "source" => {

Library/Homebrew/utils.rb

@@ -198,34 +198,9 @@ module Homebrew
     _system(cmd, *args)
   end
 
-  def self.git_origin
-    return unless Utils.git_available?
-    HOMEBREW_REPOSITORY.cd { `git config --get remote.origin.url 2>/dev/null`.chuzzle }
-  end
-
-  def self.git_head
-    return unless Utils.git_available?
-    HOMEBREW_REPOSITORY.cd { `git rev-parse --verify -q HEAD 2>/dev/null`.chuzzle }
-  end
-
-  def self.git_short_head
-    return unless Utils.git_available?
-    HOMEBREW_REPOSITORY.cd { `git rev-parse --short=4 --verify -q HEAD 2>/dev/null`.chuzzle }
-  end
-
-  def self.git_last_commit
-    return unless Utils.git_available?
-    HOMEBREW_REPOSITORY.cd { `git show -s --format="%cr" HEAD 2>/dev/null`.chuzzle }
-  end
-
-  def self.git_last_commit_date
-    return unless Utils.git_available?
-    HOMEBREW_REPOSITORY.cd { `git show -s --format="%cd" --date=short HEAD 2>/dev/null`.chuzzle }
-  end
-
   def self.homebrew_version_string
-    if pretty_revision = git_short_head
-      last_commit = git_last_commit_date
+    if pretty_revision = HOMEBREW_REPOSITORY.git_short_head
+      last_commit = HOMEBREW_REPOSITORY.git_last_commit_date
       "#{HOMEBREW_VERSION} (git revision #{pretty_revision}; last commit #{last_commit})"
     else
       "#{HOMEBREW_VERSION} (no git repository)"