Simplify setup for local bottle installation

Closes Homebrew/homebrew#22833.

Library/Homebrew/bottles.rb

@@ -11,9 +11,7 @@ def bottle_filename f, bottle_revision=nil
 end
 
 def install_bottle? f, options={:warn=>false}
-  return true if f.downloader and defined? f.downloader.local_bottle_path \
-    and f.downloader.local_bottle_path
-
+  return true if f.local_bottle_path
   return false if ARGV.build_from_source?
   return true if ARGV.force_bottle?
   return false unless f.pour_bottle?

Library/Homebrew/download_strategy.rb

@@ -2,8 +2,6 @@ require 'open-uri'
 require 'utils/json'
 
 class AbstractDownloadStrategy
-  attr_accessor :local_bottle_path
-
   attr_reader :name, :resource
 
   def initialize name, resource
@@ -251,9 +249,9 @@ end
 
 # This strategy extracts local binary packages.
 class LocalBottleDownloadStrategy < CurlDownloadStrategy
-  def initialize formula, local_bottle_path
+  def initialize formula
     super formula.name, formula.active_spec
-    @tarball_path = local_bottle_path
+    @tarball_path = formula.local_bottle_path
   end
 
   def stage

Library/Homebrew/formula.rb

@@ -23,6 +23,8 @@ class Formula
   # Will only be non-nil inside #stage and #test.
   attr_reader :buildpath, :testpath
 
+  attr_accessor :local_bottle_path
+
   # Homebrew determines the name
   def initialize name='__UNKNOWN__', path=nil
     @name = name

Library/Homebrew/formula_installer.rb

@@ -509,11 +509,10 @@ class FormulaInstaller
   end
 
   def pour
-    downloader = f.downloader
-    if downloader.local_bottle_path
-      downloader = LocalBottleDownloadStrategy.new f,
-                     downloader.local_bottle_path
+    if f.local_bottle_path
+      downloader = LocalBottleDownloadStrategy.new(f)
     else
+      downloader = f.downloader
       fetched = f.fetch
       f.verify_download_integrity fetched
     end

Library/Homebrew/formulary.rb

@@ -74,7 +74,7 @@ class Formulary
 
     def get_formula
       formula = klass.new(name)
-      formula.downloader.local_bottle_path = @bottle_filename
+      formula.local_bottle_path = @bottle_filename
       return formula
     end
   end