Fix url and version mutually exclusive options

Check url and version options are not both in options

README.rst

@@ -39,7 +39,7 @@ url
 
 version
     rubygems version, if not specified, recipe will try to find most recent
-    version.
+    version. Mutually exclusive with url option.
 
 ruby-executable
     A path to a Ruby executable. Gems will be installed using this executable.

rubygems.py

@@ -44,6 +44,10 @@ class Recipe(object):
                 "Configuration error, 'gems' option is missing")
 
         self.url = options.get('url')
+        if(self.url and options.get('version')):
+            raise zc.buildout.UserError(
+                "Configuration error, 'url' and 'version' options are mutually exclusive")
+
         # Allow to define specific ruby executable. If not, take just 'ruby'
         self.ruby_executable = options.get('ruby-executable', 'ruby')
 

tests/test_rubygems.py

@@ -288,6 +288,20 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
         recipe = rubygems.Recipe(buildout, name, options)
         recipe.install()
 
+    @fixture({'recipe': {
+        'gems': 'sass',
+        'url': 'https://rubygems.org/rubygems/rubygems-%s.zip'
+                % RUBYGEMS_DEFAULT_VERSION,
+        'version': RUBYGEMS_DEFAULT_VERSION,
+    }})
+    def test_version_and_url(self, path, patches, buildout, name, options, version):
+        self.assertRaisesRegexp(
+            zc.buildout.UserError,
+            "Configuration error, 'url' and 'version' options are mutually exclusive",
+            rubygems.Recipe, buildout, name, options
+        )
+
+
 class deployment_fixture(fixture):
     def check_output_mock(self, cmd, **kwargs):
         super(deployment_fixture, self).check_output_mock(cmd)