Persist False value for defeat_cache correctly

If cdparanoia can't work around the audio caching of a drive,
defeats_cache = False is written to the config.  However, when it is
read back the string 'False' ends up being converted to True (as it is
not an empty string).

This corrects the behaviour when reading the value back and adds tests
to make sure that both True and False can be correctly retrieved from
the config.

morituri/common/config.py

@@ -113,7 +113,7 @@ class Config:
         section = self._findDriveSection(vendor, model, release)
 
         try:
-            return bool(self._parser.get(section, 'defeats_cache'))
+            return self._parser.get(section, 'defeats_cache') == 'True'
         except ConfigParser.NoOptionError:
             raise KeyError("Could not find defeats_cache for %s/%s/%s" % (
                 vendor, model, release))

morituri/test/test_common_config.py

@@ -9,7 +9,7 @@ from morituri.common import config
 from morituri.test import common as tcommon
 
 
-class OffsetTestCase(tcommon.TestCase):
+class ConfigTestCase(tcommon.TestCase):
 
     def setUp(self):
         fd, self._path = tempfile.mkstemp(suffix=u'.morituri.test.config')
@@ -50,3 +50,19 @@ class OffsetTestCase(tcommon.TestCase):
         offset = self._config.getReadOffset(
             'Slimtype', 'eSAU208   2     ', 'ML03')
         self.assertEquals(offset, 6)
+
+    def testDefeatsCache(self):
+        self.assertRaises(KeyError, self._config.getDefeatsCache,
+            'PLEXTOR ', 'DVDR   PX-L890SA', '1.05')
+
+        self._config.setDefeatsCache(
+            'PLEXTOR ', 'DVDR   PX-L890SA', '1.05', False)
+        defeats = self._config.getDefeatsCache(
+            'PLEXTOR ', 'DVDR   PX-L890SA', '1.05')
+        self.assertEquals(defeats, False)
+
+        self._config.setDefeatsCache(
+            'PLEXTOR ', 'DVDR   PX-L890SA', '1.05', True)
+        defeats = self._config.getDefeatsCache(
+            'PLEXTOR ', 'DVDR   PX-L890SA', '1.05')
+        self.assertEquals(defeats, True)