Add an option "--root_url=" to bottle command.

Closes Homebrew/homebrew#29081.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Library/Contributions/brew_bash_completion.sh

@@ -140,7 +140,7 @@ _brew_bottle ()
     local cur="${COMP_WORDS[COMP_CWORD]}"
     case "$cur" in
     --*)
-        __brewcomp "--merge --rb --write"
+        __brewcomp "--merge --rb --write --root_url="
         return
         ;;
     esac

Library/Homebrew/cmd/bottle.rb

@@ -9,6 +9,9 @@ require 'extend/pathname'
 
 BOTTLE_ERB = <<-EOS
   bottle do
+    <% if  root_url != BottleSpecification.new.root_url %>
+    root_url "<%= root_url %>"
+    <% end  %>
     <% if  prefix.to_s != "/usr/local" %>
     prefix "<%= prefix %>"
     <% end  %>
@@ -181,7 +184,10 @@ module Homebrew extend self
       end
     end
 
+    root_url = ARGV.value("root_url")
+
     bottle = BottleSpecification.new
+    bottle.root_url(root_url) if root_url
     bottle.prefix HOMEBREW_PREFIX
     bottle.cellar relocatable ? :any : HOMEBREW_CELLAR
     bottle.revision bottle_revision