Adjust tests to suit old versions of libexiv2

Author: jim-easterbrook

tests/test_basicio.py

@@ -169,9 +169,13 @@ def test_MemIo(self):
                              exiv2.ErrorCode.kerCorruptedMetadata)
         else:
             with self.assertWarns(DeprecationWarning):
-                self.assertEqual(
-                    io.seek(len(self.data) + 10, exiv2.BasicIo.Position.beg),
-                    exiv2.ErrorCode.kerErrorMessage)
+                if exiv2.testVersion(0, 27, 2):
+                    self.assertEqual(io.seek(len(self.data) + 10,
+                                             exiv2.BasicIo.Position.beg),
+                                     exiv2.ErrorCode.kerErrorMessage)
+                else:
+                    self.assertEqual(io.seek(len(self.data) + 10,
+                                             exiv2.BasicIo.Position.beg), 0)
         with self.assertWarns(DeprecationWarning):
             self.assertEqual(io.seek(0, exiv2.BasicIo.Position.end), 0)
         with self.assertWarns(DeprecationWarning):

tests/test_error.py

@@ -58,8 +58,12 @@ def test_LogMsg(self):
         # get exiv2 to raise an exception
         with self.assertRaises(exiv2.Exiv2Error) as cm:
             image = exiv2.ImageFactory.open(bytes())
-        self.assertEqual(cm.exception.code,
-                         exiv2.ErrorCode.kerInputDataReadFailed)
+        if exiv2.testVersion(0, 27, 1):
+            self.assertEqual(cm.exception.code,
+                             exiv2.ErrorCode.kerInputDataReadFailed)
+        else:
+            self.assertEqual(cm.exception.code,
+                             exiv2.ErrorCode.kerMemoryContainsUnknownImageType)
 
 
 if __name__ == '__main__':