René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"BlockDownloadStream class in sdo\\client.py appears to be missing an object definition","articleBody":"Hello-\nIn `sdo\\client.py` the `BlockDownloadStream` class refers to the `self.crc_supported` attribute on lines 680, 738, and 812, but this class attribute does not appear to be defined (and as a side note, the `BlockUploadStream` class *does* define one).\n\nI ran across this issue when a host's block transfer request was rejected by the device, causing the library to go down one of these broken code paths:\n```\n2026-01-05 14:42:37,387 - canopen_client - ERROR - Full traceback:\nTraceback (most recent call last):\n  File \"C:\\nVent_work\\zephyr_root\\zephyr_repo\\nvent_projects\\canopen_sim\\canopen_sim\\canopen_client.py\", line 724, in upload_firmware\n    with self.node.sdo.open(index, subindex, \"wb\",\n         ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^\n                          size=total_size,\n                          ^^^^^^^^^^^^^^^^\n                          block_transfer=True) as fp:\n                          ^^^^^^^^^^^^^^^^^^^^\n  File \"C:\\Program Files\\Python313\\Lib\\site-packages\\canopen\\sdo\\client.py\", line 213, in open\n    raw_stream = BlockDownloadStream(self, index, subindex, size, request_crc_support=request_crc_support)\n  File \"C:\\Program Files\\Python313\\Lib\\site-packages\\canopen\\sdo\\client.py\", line 655, in __init__\n    response = sdo_client.request_response(request)\n  File \"C:\\Program Files\\Python313\\Lib\\site-packages\\canopen\\sdo\\client.py\", line 86, in request_response\n    return self.read_response()\n           ~~~~~~~~~~~~~~~~~~^^\n  File \"C:\\Program Files\\Python313\\Lib\\site-packages\\canopen\\sdo\\client.py\", line 74, in read_response\n    raise SdoAbortedError(abort_code)\ncanopen.sdo.exceptions.SdoAbortedError: Code 0x05040001, Unknown SDO command specified\n2026-01-05 14:42:37,391 - canopen_client - ERROR - Error uploading firmware: Code 0x05040001, Unknown SDO command specified\nException ignored in: \u003ccanopen.sdo.client.BlockDownloadStream object at 0x000001F2DDEF6A40\u003e\nTraceback (most recent call last):\n  File \"C:\\Program Files\\Python313\\Lib\\site-packages\\canopen\\sdo\\client.py\", line 793, in close\n    if self.crc_supported:\nAttributeError: 'BlockDownloadStream' object has no attribute 'crc_supported'\n2026-01-05 14:42:38,548 - canopen_client - INFO - Disconnected from CAN bus\n```\n","author":{"url":"https://github.com/Eqqm4n","@type":"Person","name":"Eqqm4n"},"datePublished":"2026-01-05T22:44:41.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/624/canopen/issues/624"}