Allow formulae to use __END__

For this to work the "running script" must be the formulae file. Making this
so wasn't so hard, there is now an install.rb script which is included with
the -r flag to the ruby executable. An at_exit handler calls the install
function.

Having the install logic in its own file made it feel like there was so much
space that I added extra error handling. So there is something to be said for
separating functionality out into its own files.

Still the error handling sucks, we'll need to marshall the exception back to
the bin/brew command. Which is another PITA.

Still overall I think this will prove worthwhile. But if it doesn't we'll
revert.

As a first usage, you can put a diff after __END__ and return DATA from
Formula::patches to make Homebrew aware of it.

1 files changed, 22 insertions, 7 deletions

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index a5a69b496..bf7e55865 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -114,6 +114,8 @@ class Formula
   #     :p1 =>  'http://bar.com/patch2',
   #     :p2 => ['http://moo.com/patch5', 'http://moo.com/patch6']
   #   }
+  # The final option is to return DATA, then put a diff after __END__ and you
+  # can still return a Hash with DATA as the value for a patch level key.
   def patches; [] end
   # reimplement and specify dependencies
   def deps; end
@@ -128,6 +130,8 @@ class Formula
     stage do
       begin
         patch
+        # we allow formulas to do anything they want to the Ruby process
+        # so load any deps before this point! And exit asap afterwards
         yield self
       rescue Interrupt, RuntimeError, SystemCallError => e
         raise unless ARGV.debug?
@@ -158,7 +162,13 @@ class Formula
   end
 
   def self.factory name
-    require self.path(name)
+    path = Pathname.new(name)
+    if path.absolute?
+      require name
+      name = path.stem
+    else
+      require self.path(name)
+    end
     return eval(self.class_s(name)).new(name)
   rescue LoadError
     raise FormulaUnavailableError.new(name)
@@ -242,7 +252,7 @@ private
       yield
     end
   end
-
+  
   def patch
     return if patches.empty?
 
@@ -258,17 +268,20 @@ private
     n=0
     patch_defns.each do |arg, urls|
       urls.each do |url|
-        p = {:filename => '%03d-homebrew.patch' % n+=1, :compression => false}
+        p = {:filename => '%03d-homebrew.diff' % n+=1, :compression => false}
 
-        if url =~ %r[^\w+\://]
+        if defined? DATA and url == DATA
+          pn=Pathname.new p[:filename]
+          pn.write DATA.read
+        elsif url =~ %r[^\w+\://]
           out_fn = p[:filename]
           case url
           when /\.gz$/
             p[:compression] = :gzip
-            out_fn << '.gz'
+            out_fn += '.gz'
           when /\.bz2$/
             p[:compression] = :bzip2
-            out_fn << '.bz2'
+            out_fn += '.bz2'
           end
           p[:curl_args] = [url, '-o', out_fn]
         else
@@ -281,9 +294,11 @@ private
         patch_list << p
       end
     end
+    
+    return if patch_list.empty?
 
     # downloading all at once is much more efficient, espeically for FTP
-    curl *(patch_list.collect { |p| p[:curl_args] }).flatten
+    curl *(patch_list.collect{|p| p[:curl_args]}.select{|p| p}.flatten)
 
     patch_list.each do |p|
       case p[:compression]