New patch implementation and DSL

This commit introduces a new patch implementation that supports
checksums and caching.

Patches are declared in blocks:

  patch do
    url ...
    sha1 ...
  end

A strip level of -p1 is assumed. It can be overridden using a symbol
argument:

  patch :p0 do
    url ...
    sha1 ...
  end

Patches can be declared in stable, devel, and head blocks. This form is
preferred over using conditionals.

  stable do
    # ...

    patch do
      url ...
      sha1 ...
    end
  end

Embedded (__END__) patches are declared like so:

  patch :DATA
  patch :p0, :DATA

Patches can also be embedded by passing a string. This makes it possible
to provide multiple embedded patches while making only some of them
conditional.

  patch :p0, "..."

1 files changed, 9 insertions, 2 deletions

diff --git a/Library/Homebrew/software_spec.rb b/Library/Homebrew/software_spec.rb
index 43969b2fa..0349dd3dd 100644
--- a/Library/Homebrew/software_spec.rb
+++ b/Library/Homebrew/software_spec.rb
@@ -5,12 +5,13 @@ require 'version'
 require 'build_options'
 require 'dependency_collector'
 require 'bottles'
+require 'patch'
 
 class SoftwareSpec
   extend Forwardable
 
-  attr_reader :name
-  attr_reader :build, :resources, :owner
+  attr_reader :name, :owner
+  attr_reader :build, :resources, :patches
   attr_reader :dependency_collector
   attr_reader :bottle_specification
 
@@ -25,6 +26,7 @@ class SoftwareSpec
     @build = BuildOptions.new(ARGV.options_only)
     @dependency_collector = DependencyCollector.new
     @bottle_specification = BottleSpecification.new
+    @patches = []
   end
 
   def owner= owner
@@ -35,6 +37,7 @@ class SoftwareSpec
       r.owner     = self
       r.version ||= version
     end
+    patches.each { |p| p.owner = self }
   end
 
   def url val=nil, specs={}
@@ -84,6 +87,10 @@ class SoftwareSpec
   def requirements
     dependency_collector.requirements
   end
+
+  def patch strip=:p1, io=nil, &block
+    patches << Patch.create(strip, io, &block)
+  end
 end
 
 class HeadSoftwareSpec < SoftwareSpec