Merge branch 'master' into gracefully-handle-pdo-save-readonly

Author: acolomb

canopen/sdo/server.py

@@ -66,7 +66,11 @@ def init_upload(self, request):
 
         data = self._node.get_data(index, subindex, check_readable=True)
         size = len(data)
-        if size <= 4:
+        if size == 0:
+            logger.info("No content to upload for 0x%04X:%02X", index, subindex)
+            self.abort(0x0800_0024)
+            return
+        elif size <= 4:
             logger.info("Expedited upload for 0x%04X:%02X", index, subindex)
             res_command |= EXPEDITED
             res_command |= (4 - size) << 2

test/test_local.py

@@ -62,6 +62,13 @@ def test_expedited_upload_default_value_real(self):
         sampling_rate = self.remote_node.sdo["Sensor Sampling Rate (Hz)"].raw
         self.assertAlmostEqual(sampling_rate, 5.2, places=2)
 
+    def test_upload_zero_length(self):
+        self.local_node.sdo["Manufacturer device name"].raw = b""
+        with self.assertRaises(canopen.SdoAbortedError) as error:
+            self.remote_node.sdo["Manufacturer device name"].data
+        # Should be No data available
+        self.assertEqual(error.exception.code, 0x0800_0024)
+
     def test_segmented_upload(self):
         self.local_node.sdo["Manufacturer device name"].raw = "Some cool device"
         device_name = self.remote_node.sdo["Manufacturer device name"].data