Update upgrade/outdated methods for head versions

Introduce `--fetch-HEAD` option. Without this option upgrade and
outdated never fetch latest upstream commit to detect if HEAD is
outdated -- tabs are used instead. However, if option is passed,
we fetch commit from upstream, which is more time consuming,
but we can be sure that version is up-to-date or outdated.

Library/Homebrew/cmd/outdated.rb

@@ -32,10 +32,19 @@ module Homebrew
 
   def print_outdated(formulae)
     verbose = ($stdout.tty? || ARGV.verbose?) && !ARGV.flag?("--quiet")
+    fetch_head = ARGV.fetch_head?
 
-    formulae.select(&:outdated?).each do |f|
+    outdated_formulae = formulae.select { |f| f.outdated?(:fetch_head => fetch_head) }
+
+    outdated_formulae.each do |f|
       if verbose
-        puts "#{f.full_name} (#{f.outdated_versions*", "} < #{f.pkg_version})"
+        outdated_versions = f.outdated_versions(:fetch_head => fetch_head)
+        current_version = if f.head? && outdated_versions.any? { |v| v.to_s == f.pkg_version.to_s }
+          "latest HEAD"
+        else
+          f.pkg_version.to_s
+        end
+        puts "#{f.full_name} (#{outdated_versions.join(", ")}) < #{current_version}"
       else
         puts f.full_name
       end
@@ -44,11 +53,20 @@ module Homebrew
 
   def print_outdated_json(formulae)
     json = []
-    outdated = formulae.select(&:outdated?).each do |f|
+    fetch_head = ARGV.fetch_head?
+    outdated_formulae = formulae.select { |f| f.outdated?(:fetch_head => fetch_head) }
+
+    outdated = outdated_formulae.each do |f|
+      outdated_versions = f.outdated_versions(:fetch_head => fetch_head)
+      current_version = if f.head? && outdated_versions.any? { |v| v.to_s == f.pkg_version.to_s }
+        "HEAD"
+      else
+        f.pkg_version.to_s
+      end
 
       json << { :name => f.full_name,
-                :installed_versions => f.outdated_versions.collect(&:to_s),
+                :installed_versions => outdated_versions.collect(&:to_s),
-                :current_version => f.pkg_version.to_s }
+                :current_version => current_version }
     end
     puts Utils::JSON.dump(json)
 

Library/Homebrew/cmd/upgrade.rb

@@ -19,10 +19,15 @@ module Homebrew
     Homebrew.perform_preinstall_checks
 
     if ARGV.named.empty?
-      outdated = Formula.installed.select(&:outdated?)
+      outdated = Formula.installed.select do |f|
+        f.outdated?(:fetch_head => ARGV.fetch_head?)
+      end
+
       exit 0 if outdated.empty?
     else
-      outdated = ARGV.resolved_formulae.select(&:outdated?)
+      outdated = ARGV.resolved_formulae.select do |f|
+        f.outdated?(:fetch_head => ARGV.fetch_head?)
+      end
 
       (ARGV.resolved_formulae - outdated).each do |f|
         versions = f.installed_kegs.map { |keg| keg.version }

Library/Homebrew/extend/ARGV.rb

@@ -223,6 +223,10 @@ module HomebrewArgvExtension
     include? "--force-bottle"
   end
 
+  def fetch_head?
+    include? "--fetch-HEAD"
+  end
+
   # eg. `foo -ns -i --bar` has three switches, n, s and i
   def switch?(char)
     return false if char.length > 1