Use multiple argument form of system

Library/Homebrew/build.rb

@@ -147,8 +147,8 @@ class Build
 
     f.brew do
       if ARGV.flag? '--git'
-        system "git init"
-        system "git add -A"
+        system "git", "init"
+        system "git", "add", "-A"
       end
       if ARGV.interactive?
         ohai "Entering interactive mode"

Library/Homebrew/cmd/tap.rb

@@ -21,7 +21,7 @@ module Homebrew
     # we downcase to avoid case-insensitive filesystem issues
     tapd = HOMEBREW_LIBRARY/"Taps/#{user.downcase}/homebrew-#{repo.downcase}"
     return false if tapd.directory?
-    abort unless system "git clone https://github.com/#{repouser}/homebrew-#{repo} #{tapd}"
+    abort unless system "git", "clone", "https://github.com/#{repouser}/homebrew-#{repo}", tapd.to_s
 
     files = []
     tapd.find_formula { |file| files << file }

Library/Homebrew/cmd/update.rb

@@ -77,17 +77,17 @@ module Homebrew
   private
 
   def git_init_if_necessary
-    if Dir['.git/*'].empty?
-      safe_system "git init"
-      safe_system "git config core.autocrlf false"
-      safe_system "git remote add origin https://github.com/Homebrew/homebrew.git"
-      safe_system "git fetch origin"
-      safe_system "git reset --hard origin/master"
+    if Dir[".git/*"].empty?
+      safe_system "git", "init"
+      safe_system "git", "config", "core.autocrlf", "false"
+      safe_system "git", "remote", "add", "origin", "https://github.com/Homebrew/homebrew.git"
+      safe_system "git", "fetch", "origin"
+      safe_system "git", "reset", "--hard", "origin/master"
     end
 
     if `git remote show origin -n` =~ /Fetch URL: \S+mxcl\/homebrew/
-      safe_system "git remote set-url origin https://github.com/Homebrew/homebrew.git"
-      safe_system "git remote set-url --delete origin .*mxcl\/homebrew.*"
+      safe_system "git", "remote", "set-url", "origin", "https://github.com/Homebrew/homebrew.git"
+      safe_system "git", "remote", "set-url", "--delete", "origin", ".*mxcl\/homebrew.*"
     end
   rescue Exception
     FileUtils.rm_rf ".git"
@@ -138,12 +138,12 @@ class Updater
   attr_reader :initial_revision, :current_revision
 
   def pull!
-    safe_system "git checkout -q master"
+    safe_system "git", "checkout", "-q", "master"
 
     @initial_revision = read_current_revision
 
     # ensure we don't munge line endings on checkout
-    safe_system "git config core.autocrlf false"
+    safe_system "git", "config", "core.autocrlf", "false"
 
     args = ["pull"]
     args << "--rebase" if ARGV.include? "--rebase"