Add a git-integration formula

Library/Formula/git-integration.rb

@@ -0,0 +1,48 @@
+require 'formula'
+
+class SufficientlyRecentGit < Requirement
+  fatal true
+  default_formula 'git'
+
+  satisfy do
+    # `git stripspace` condition copy/pasted from git-integration 0.2
+    system 'git stripspace --comment-lines </dev/null 2>/dev/null'
+  end
+
+  def message
+    "Your Git is too old.  Please upgrade to Git 1.8.2 or newer."
+  end
+end
+
+class GitIntegration < Formula
+  homepage 'http://johnkeeping.github.io/git-integration/'
+  url 'https://github.com/johnkeeping/git-integration/archive/v0.2.zip'
+  sha1 'ce86564077a683c8ce270c85530f9100f3f8c950'
+
+  depends_on 'asciidoc' => [:build, :optional]
+  depends_on SufficientlyRecentGit
+
+  def install
+    ENV["XML_CATALOG_FILES"] = "#{HOMEBREW_PREFIX}/etc/xml/catalog"
+    (buildpath/"config.mak").write "prefix = #{prefix}"
+    system "make", "install"
+    if build.with? "asciidoc"
+      system "make", "install-doc"
+    end
+    system "make", "install-completion"
+  end
+
+  test do
+    system "git", "init"
+    system "git", "commit", "--allow-empty", "-m", "An initial commit"
+    system "git", "checkout", "-b", "branch-a", "master"
+    system "git", "commit", "--allow-empty", "-m", "A commit on branch-a"
+    system "git", "checkout", "-b", "branch-b", "master"
+    system "git", "commit", "--allow-empty", "-m", "A commit on branch-b"
+    system "git", "checkout", "master"
+    system "git", "integration", "--create", "integration"
+    system "git", "integration", "--add", "branch-a"
+    system "git", "integration", "--add", "branch-b"
+    system "git", "integration", "--rebuild"
+  end
+end