Fix change_make_var! for empty variables.

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

Library/Homebrew/test/test_inreplace.rb

@@ -6,6 +6,14 @@ class InreplaceTest < Test::Unit::TestCase
     s1.change_make_var! "FLAG", "def"
     assert_equal "FLAG=def", s1
   end
+
+  def test_change_make_var_empty
+    # Replace empty flag
+    s1="FLAG = \nFLAG2=abc"
+    s1.extend(HomebrewInreplaceExtension)
+    s1.change_make_var! "FLAG", "def"
+    assert_equal "FLAG=def\nFLAG2=abc", s1
+  end
     
   def test_change_make_var_append
     # Append to flag

Library/Homebrew/utils.rb

@@ -157,7 +157,7 @@ module HomebrewInreplaceExtension
   # value with "new_value", or removes the definition entirely.
   def change_make_var! flag, new_value
     new_value = "#{flag}=#{new_value}"
-    gsub! Regexp.new("^#{flag}\\s*=\\s*(.*)$"), new_value
+    gsub! Regexp.new("^#{flag}\\s*=[ \\t]*(.*)$"), new_value
   end
   # Removes variable assignments completely.
   def remove_make_var! flags