remove_make_var! should not leave an empty assignment

Library/Homebrew/test/test_inreplace.rb

@@ -14,13 +14,21 @@ class InreplaceTest < Test::Unit::TestCase
     s1.change_make_var! "FLAG", "\\1 def"
     assert_equal "FLAG=abc def", s1
   end
+  
+  def test_change_make_var_shell_style
+    # Shell variables have no spaces around =
+    s1="FLAG=abc"
+    s1.extend(HomebrewInreplaceExtension)
+    s1.change_make_var! "FLAG", "def"
+    assert_equal "FLAG=def", s1
+  end
 
   def test_remove_make_var
     # Replace flag
     s1="FLAG = abc\nFLAG2 = def"
     s1.extend(HomebrewInreplaceExtension)
     s1.remove_make_var! "FLAG"
-    assert_equal "FLAG=\nFLAG2 = def", s1
+    assert_equal "FLAG2 = def", s1
   end
 
   def test_remove_make_vars
@@ -28,6 +36,6 @@ class InreplaceTest < Test::Unit::TestCase
     s1="FLAG = abc\nFLAG2 = def"
     s1.extend(HomebrewInreplaceExtension)
     s1.remove_make_var! ["FLAG", "FLAG2"]
-    assert_equal "FLAG=\nFLAG2=", s1
+    assert_equal "", s1
   end
 end

Library/Homebrew/utils.rb

@@ -177,16 +177,20 @@ def archs_for_command cmd
     end
 end
 
+# String extensions added by inreplace below.
 module HomebrewInreplaceExtension
   # Looks for Makefile style variable defintions and replaces the
   # value with "new_value", or removes the definition entirely.
-  # See inreplace in utils.rb
+  def change_make_var! flag, new_value
-  def change_make_var! flag, new_value=nil
+    new_value = "#{flag}=#{new_value}"
-    new_value = "#{flag}=#{new_value}" unless new_value == nil
     gsub! Regexp.new("^#{flag}\\s*=\\s*(.*)$"), new_value
   end
+  # Removes variable assignments completely.
   def remove_make_var! flags
-    flags.each { |flag| change_make_var! flag, "" }
+    flags.each do |flag|
+      # Also remove trailing \n, if present.
+      gsub! Regexp.new("^#{flag}\\s*=(.*)$\n?"), ""
+    end
   end
 end