From 7718c939b06987ff8f1ecd599c8ace6f998ce180 Mon Sep 17 00:00:00 2001
From: Jack Nagel <jacknagel@gmail.com>
Date: Mon, 23 Apr 2012 20:21:12 -0500
Subject: [PATCH] GitDownloadStrategy optimization

The current series of fetch invocations in GitDownloadStrategy has the
unfortunate behavior of fetching full history even in shallow clones
that only need the history between the clone point and the remote HEAD.
It should be possible to determine if it is actually necessary to fetch
the full history, including all tags, and if it is not to avoid this
overhead.

Fixes #11958, and several other recurring problems.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
---
 Library/Formula/git-multipush.rb              |  4 +-
 Library/Formula/reattach-to-user-namespace.rb |  2 +-
 Library/Formula/topgit.rb                     |  2 +-
 Library/Homebrew/download_strategy.rb         | 43 ++++++++++++-------
 4 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/Library/Formula/git-multipush.rb b/Library/Formula/git-multipush.rb
index 7ab88fd741e1..a6c70b4b72f3 100644
--- a/Library/Formula/git-multipush.rb
+++ b/Library/Formula/git-multipush.rb
@@ -5,13 +5,13 @@ class GitMultipush < Formula
   url 'http://git-multipush.googlecode.com/files/git-multipush-2.3.tar.bz2'
   sha1 'a53f171af5e794afe9b1de6ccd9bd0661db6fd91'
 
-  head 'https://github.com/gavinbeatty/git-multipush.git', :sha => 'HEAD'
+  head 'https://github.com/gavinbeatty/git-multipush.git', :revision => 'HEAD'
 
   depends_on 'asciidoc' => :build if ARGV.build_head?
 
   def install
     if ARGV.build_head?
-      ENV['GIT_DIR'] = cached_location/'.git'
+      ENV['GIT_DIR'] = cached_download/'.git'
       inreplace 'make/gen-version.mk', '.git', '$(GIT_DIR)'
       system "make"
     end
diff --git a/Library/Formula/reattach-to-user-namespace.rb b/Library/Formula/reattach-to-user-namespace.rb
index aed66dadc381..7f9357399b00 100644
--- a/Library/Formula/reattach-to-user-namespace.rb
+++ b/Library/Formula/reattach-to-user-namespace.rb
@@ -3,7 +3,7 @@
 class ReattachToUserNamespace < Formula
   head 'https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard.git'
   homepage 'https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard'
-  url 'https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard.git', :tag => 'dadea0aa48259c704d0b412b9588de2f5623e323'
+  url 'https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard.git', :revision => 'dadea0aa48259c704d0b412b9588de2f5623e323'
   version 'dadea0'
 
   def options
diff --git a/Library/Formula/topgit.rb b/Library/Formula/topgit.rb
index bca8c570a950..9d5032642275 100644
--- a/Library/Formula/topgit.rb
+++ b/Library/Formula/topgit.rb
@@ -2,7 +2,7 @@
 
 class Topgit < Formula
   homepage 'http://repo.or.cz/w/topgit.git'
-  url 'git://repo.or.cz/topgit.git', :tag => '1744aca50f3d7b6b4863523207e5010e112dfb85'
+  url 'git://repo.or.cz/topgit.git', :revision => '1744aca50f3d7b6b4863523207e5010e112dfb85'
   version '0.8'
 
   def install
diff --git a/Library/Homebrew/download_strategy.rb b/Library/Homebrew/download_strategy.rb
index 6b8aff900ce0..6a5dd6ac7c59 100644
--- a/Library/Homebrew/download_strategy.rb
+++ b/Library/Homebrew/download_strategy.rb
@@ -324,14 +324,10 @@ def cached_location
   end
 
   def support_depth?
-    !commit_history_required? and depth_supported_host?
+    @spec != :revision and host_supports_depth?
   end
 
-  def commit_history_required?
-    @spec == :sha
-  end
-
-  def depth_supported_host?
+  def host_supports_depth?
     @url =~ %r(git://) or @url =~ %r(https://github.com/)
   end
 
@@ -352,16 +348,31 @@ def fetch
 
     unless @clone.exist?
       # Note: first-time checkouts are always done verbosely
-      git_args = %w(git clone)
-      git_args << "--depth" << "1" if support_depth?
-      git_args << @url << @clone
-      safe_system(*git_args)
+      clone_args = %w[git clone]
+      clone_args << '--single-branch'
+      clone_args << '--depth' << '1' if support_depth?
+
+      case @spec
+      when :branch, :tag
+        clone_args << '--branch' << @ref
+      end
+
+      clone_args << @url << @clone
+      safe_system(*clone_args)
     else
       puts "Updating #{@clone}"
       Dir.chdir(@clone) do
-        safe_system 'git', 'remote', 'set-url', 'origin', @url
-        quiet_safe_system 'git', 'fetch', 'origin'
-        quiet_safe_system 'git', 'fetch', '--tags' if @spec == :tag
+        safe_system 'git', 'config', 'remote.origin.url', @url
+
+        safe_system 'git', 'config', 'remote.origin.fetch', case @spec
+          when :branch then "+refs/heads/#{@ref}:refs/remotes/origin/#{@ref}"
+          when :tag then "+refs/tags/#{@ref}:refs/tags/#{@ref}"
+          else '+refs/heads/master:refs/remotes/origin/master'
+          end
+
+        git_args = %w[git fetch origin]
+        git_args << '--depth' << '1' if support_depth?
+        quiet_safe_system(*git_args)
       end
     end
   end
@@ -373,9 +384,9 @@ def stage
         ohai "Checking out #{@spec} #{@ref}"
         case @spec
         when :branch
-          nostdout { quiet_safe_system 'git', 'checkout', "origin/#{@ref}" }
-        when :tag, :sha
-          nostdout { quiet_safe_system 'git', 'checkout', @ref }
+          nostdout { quiet_safe_system 'git', 'checkout', "origin/#{@ref}", '--' }
+        when :tag, :revision
+          nostdout { quiet_safe_system 'git', 'checkout', @ref, '--' }
         end
       else
         # otherwise the checkout-index won't checkout HEAD