Test behaviour regarding multi-line ignore parsing in config_file

At time of writing, these tests fail. If this is later fixed, someone
may wish to remove this warning!

testsuite/test_all.py

@@ -46,11 +46,12 @@ def test_own_dog_food(self):
 
 
 def suite():
-    from testsuite import test_api, test_shell, test_util
+    from testsuite import test_api, test_parser, test_shell, test_util
 
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(Pep8TestCase))
     suite.addTest(unittest.makeSuite(test_api.APITestCase))
+    suite.addTest(unittest.makeSuite(test_parser.ParserTestCase))
     suite.addTest(unittest.makeSuite(test_shell.ShellTestCase))
     suite.addTest(unittest.makeSuite(test_util.UtilTestCase))
     return suite

testsuite/test_parser.py

@@ -0,0 +1,61 @@
+import os
+import tempfile
+import unittest
+
+import pep8
+
+
+def _process_file(contents):
+    with tempfile.NamedTemporaryFile(delete=False) as f:
+        f.write(contents)
+
+    options, args = pep8.process_options(config_file=f.name)
+    os.remove(f.name)
+
+    return options, args
+
+
+class ParserTestCase(unittest.TestCase):
+
+    def test_vanilla_ignore_parsing(self):
+        contents = b"""
+[pep8]
+ignore = E226,E24
+        """
+        options, args = _process_file(contents)
+
+        self.assertEqual(options.ignore, ["E226", "E24"])
+
+    def test_multiline_ignore_parsing(self):
+        contents = b"""
+[pep8]
+ignore =
+    E226,
+    E24
+        """
+
+        options, args = _process_file(contents)
+
+        self.assertEqual(options.ignore, ["E226", "E24"])
+
+    def test_trailing_comma_ignore_parsing(self):
+        contents = b"""
+[pep8]
+ignore = E226,
+        """
+
+        options, args = _process_file(contents)
+
+        self.assertEqual(options.ignore, ["E226"])
+
+    def test_multiline_trailing_comma_ignore_parsing(self):
+        contents = b"""
+[pep8]
+ignore =
+    E226,
+    E24,
+        """
+
+        options, args = _process_file(contents)
+
+        self.assertEqual(options.ignore, ["E226", "E24"])