1 files changed, 21 insertions, 0 deletions
diff --git a/python/google/protobuf/internal/descriptor_database_test.py b/python/google/protobuf/internal/descriptor_database_test.py
index 1f1a3db9..f97477b3 100644
--- a/python/google/protobuf/internal/descriptor_database_test.py
+++ b/python/google/protobuf/internal/descriptor_database_test.py
@@ -38,6 +38,7 @@ try:
   import unittest2 as unittest  #PY26
 except ImportError:
   import unittest
+import warnings
 
 from google.protobuf import unittest_pb2
 from google.protobuf import descriptor_pb2
@@ -98,6 +99,26 @@ class DescriptorDatabaseTest(unittest.TestCase):
                       db.FindFileContainingSymbol,
                       'protobuf_unittest.NoneMessage')
 
+  def testConflictRegister(self):
+    db = descriptor_database.DescriptorDatabase()
+    unittest_fd = descriptor_pb2.FileDescriptorProto.FromString(
+        unittest_pb2.DESCRIPTOR.serialized_pb)
+    db.Add(unittest_fd)
+    conflict_fd = descriptor_pb2.FileDescriptorProto.FromString(
+        unittest_pb2.DESCRIPTOR.serialized_pb)
+    conflict_fd.name = 'other_file'
+    with warnings.catch_warnings(record=True) as w:
+      # Cause all warnings to always be triggered.
+      warnings.simplefilter('always')
+      db.Add(conflict_fd)
+      self.assertTrue(len(w))
+      self.assertIs(w[0].category, RuntimeWarning)
+      self.assertIn('Conflict register for file "other_file": ',
+                    str(w[0].message))
+      self.assertIn('already defined in file '
+                    '"google/protobuf/unittest.proto"',
+                    str(w[0].message))
+
 
 if __name__ == '__main__':
   unittest.main()