treat an unknown key in a settings_pack as an error in python (#1287)

bindings/python/src/session.cpp

@@ -112,7 +112,11 @@ namespace
 			std::string const key = extract<std::string>(iterkeys[i]);
 
 			int sett = setting_by_name(key);
-			if (sett < 0) continue;
+			if (sett < 0)
+			{
+				PyErr_SetString(PyExc_ValueError, ("unknown name in settings_pack: " + key).c_str());
+				throw_error_already_set();
+			}
 
 			TORRENT_TRY
 			{

bindings/python/test.py

@@ -81,7 +81,7 @@ class test_torrent_info(unittest.TestCase):
 		idx = 0
 		expected = ['bar.txt', 'var.txt']
 		for f in files:
-			print f.path
+			print(f.path)
 
 			self.assertEqual(os.path.split(f.path)[1], expected[idx])
 			self.assertEqual(os.path.split(os.path.split(f.path)[0]), ('temp', 'foo'))
@@ -165,6 +165,13 @@ class test_session(unittest.TestCase):
 		self.assertTrue(isinstance(a.values, dict))
 		self.assertTrue(len(a.values) > 0)
 
+	def test_unknown_settings(self):
+		try:
+			s = lt.session({'unexpected-key-name': 42})
+			self.assertFalse('should have thrown an exception')
+		except Exception as e:
+			print(e)
+
 	def test_deprecated_settings(self):
 
 		# this detects whether libtorrent was built with deprecated APIs