Fix Ruby warnings.

Fixes Homebrew/homebrew#11966.

Library/Homebrew/dependencies.rb

@@ -105,7 +105,7 @@ class LanguageModuleDependency < Requirement
   def fatal?; true; end
 
   def satisfied?
-    quiet_system *the_test
+    quiet_system(*the_test)
   end
 
   def message; <<-EOS.undent

Library/Homebrew/download_strategy.rb

@@ -355,7 +355,7 @@ class GitDownloadStrategy < AbstractDownloadStrategy
       git_args = %w(git clone)
       git_args << "--depth" << "1" if support_depth?
       git_args << @url << @clone
-      safe_system *git_args
+      safe_system(*git_args)
     else
       puts "Updating #{@clone}"
       Dir.chdir(@clone) do

Library/Homebrew/extend/fileutils.rb

@@ -27,6 +27,7 @@ module FileUtils extend self
   end
 
   # A version of mkdir that also changes to that folder in a block.
+  alias mkdir_old mkdir
   def mkdir name, &block
     FileUtils.mkdir(name)
     if block_given?

Library/Homebrew/extend/pathname.rb

@@ -117,6 +117,7 @@ class Pathname
   end
 
   # extended to support common double extensions
+  alias extname_old extname
   def extname
     return $1 if to_s =~ bottle_regex
     return $1 if to_s =~ old_bottle_regex

Library/Homebrew/formula.rb

@@ -592,14 +592,14 @@ private
 
     def stable &block
       raise "url and md5 must be specified in a block" unless block_given?
-      instance_eval &block unless ARGV.build_devel? or ARGV.build_head?
+      instance_eval(&block) unless ARGV.build_devel? or ARGV.build_head?
     end
 
     def devel &block
       raise "url and md5 must be specified in a block" unless block_given?
       if ARGV.build_devel?
         @mirrors = nil # clear out mirrors from the stable release
-        instance_eval &block
+        instance_eval(&block)
       end
     end
 
@@ -632,7 +632,7 @@ private
         end
       end
 
-      bottle_block.instance_eval &block
+      bottle_block.instance_eval(&block)
       @bottle_version, @bottle_url, @bottle_sha1 = bottle_block.data
     end
 

Library/Homebrew/formula_support.rb

@@ -19,7 +19,9 @@ class SoftwareSpecification
   def initialize url, specs=nil
     raise "No url provided" if url.nil?
     @url = url
-    unless specs.nil?
+    if specs.nil?
+      @using = nil
+    else
       # Get download strategy hint, if any
       @using = specs.delete :using
       # The rest of the specs are for source control