Support default Options values of None. (Gary Oberbrunner)

2 files changed, 16 insertions, 2 deletions

diff --git a/src/engine/SCons/Options/OptionsTests.py b/src/engine/SCons/Options/OptionsTests.py
index afcb4d3..4248dc3 100644
--- a/src/engine/SCons/Options/OptionsTests.py
+++ b/src/engine/SCons/Options/OptionsTests.py
@@ -244,7 +244,21 @@ class OptionsTestCase(unittest.TestCase):
         env = Environment()
         opts.Update(env, {})
         assert not env.has_key('ANSWER')
-        
+
+        # Test that a default value of None is all right.
+        test = TestSCons.TestSCons()
+        file = test.workpath('custom.py')
+        opts = SCons.Options.Options(file)
+
+        opts.Add('ANSWER',
+                 "This is the answer",
+                 None,
+                 check)
+
+        env = Environment()
+        opts.Update(env, {})
+        assert not env.has_key('ANSWER')
+
     def test_args(self):
         """Test updating an Environment with arguments overridden"""
 
diff --git a/src/engine/SCons/Options/__init__.py b/src/engine/SCons/Options/__init__.py
index 521171c..fdaee92 100644
--- a/src/engine/SCons/Options/__init__.py
+++ b/src/engine/SCons/Options/__init__.py
@@ -165,7 +165,7 @@ class Options:
 
         # Finally validate the values:
         for option in self.options:
-            if option.validator:
+            if option.validator and values.has_key(option.key):
                 option.validator(option.key, env.subst('${%s}'%option.key), env)
 
     def Save(self, filename, env):