From f6052e8cc44e885f4a8b31d77d1c579169779ac6 Mon Sep 17 00:00:00 2001
From: Adam Vandenberg <flangy@gmail.com>
Date: Fri, 9 Mar 2012 10:26:46 -0800
Subject: [PATCH] Add Patches class

---
 Library/Homebrew/patches.rb | 103 ++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Library/Homebrew/patches.rb

diff --git a/Library/Homebrew/patches.rb b/Library/Homebrew/patches.rb
new file mode 100644
index 0000000000..34a59cf2bf
--- /dev/null
+++ b/Library/Homebrew/patches.rb
@@ -0,0 +1,103 @@
+class Patches
+  # The patches defined in a formula and the DATA from that file
+  def initialize patches
+    @patches = []
+    return if patches.nil?
+
+    normalize_patches(patches).each do |patch_p, urls|
+      # Wrap the urls list in an array if it isn't already;
+      # DATA.each does each line, which doesn't work so great
+      urls = [urls] unless urls.kind_of? Array
+      urls.each_with_index do |url, n|
+        @patches << Patch.new(patch_p, '%03d-homebrew.diff' % n, url)
+      end
+    end
+  end
+
+  # Collects the urls and output names of all external patches
+  def external_curl_args
+    @patches.select{|p| p.external?}.collect{|p| p.curl_args}.flatten
+  end
+
+  def each(&blk)
+    @patches.each(&blk)
+  end
+  def empty?
+    @patches.empty?
+  end
+
+private
+
+  def normalize_patches patches
+    if patches.kind_of? Hash
+      patches
+    else
+      { :p1 => patches } # We assume -p1
+    end
+  end
+
+end
+
+class Patch
+  attr_reader :compression
+  attr_reader :url
+
+  def initialize patch_p, filename, url
+    @patch_p = patch_p
+    @patch_filename = filename
+    @compression = false
+    @url = nil
+
+    if url.kind_of? File # true when DATA is passed
+      write_data url
+    elsif looks_like_url(url)
+      @download_filename = @patch_filename
+      @url = url # Save URL
+      case @url
+      when /\.gz$/
+        @compression = :gzip
+        @download_filename += '.gz'
+      when /\.bz2$/
+        @compression = :bzip2
+        @download_filename += '.bz2'
+      end
+    else
+      # it's a file on the local filesystem
+      # use URL as the filename for patch
+      @patch_filename = url
+    end
+  end
+
+  def external?
+    !!@url
+  end
+
+  def compressed?
+    !!@compression
+  end
+
+  def patch_args
+    ["-#{@patch_p}", '-i', @patch_filename]
+  end
+
+  def curl_args
+    [@url, '-o', @download_filename]
+  end
+
+private
+
+  # Write the given file object (DATA) out to a local file for patch
+  def write_data f
+    pn = Pathname.new @patch_filename
+    pn.write(brew_var_substitution f.read.to_s)
+  end
+
+  # Do any supported substitutions of HOMEBREW vars in a DATA patch
+  def brew_var_substitution s
+    s.gsub("HOMEBREW_PREFIX", HOMEBREW_PREFIX)
+  end
+
+  def looks_like_url str
+    str =~ %r[^\w+\://]
+  end
+end