Intermittent failure to fetch telemetry, with "zlib.error: Error -5 while decompressing data: incomplete or truncated stream"

[lurgh]

I am intermittently (but regularly) getting a failure in haomnilogic-local's update attempt due to pyomnilogic_local async_get_telemetry failing with "zlib.error: Error -5 while decompressing data: incomplete or truncated stream"`. It has been happening for at least a couple weeks - I believe dating back before I installed the 2.0.0 integration but I am not certain. There is a regular intermittent pattern to the failures. It seems plausible that it is related to the telemetry size changing and sometimes crossing a critical threshold.

Here is a stack trace:

2026-06-19 21:56:32.668 ERROR (MainThread) [custom_components.omnilogic_local.coordinator] Error fetching OmniLogic data: Failed to update data from OmniLogic
2026-06-19 21:56:32.668 DEBUG (MainThread) [custom_components.omnilogic_local.coordinator] Full error:
Traceback (most recent call last):
  File "/config/custom_components/omnilogic_local/coordinator.py", line 47, in _async_update_data
    await self.omni.refresh(force_telemetry=True)
  File "/usr/local/lib/python3.14/site-packages/pyomnilogic_local/omnilogic.py", line 148, in refresh
    self.telemetry = await self._api.async_get_telemetry()
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/pyomnilogic_local/api/api.py", line 247, in async_get_telemetry
    resp = await self.async_send_and_receive(MessageType.GET_TELEMETRY, req_body)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/pyomnilogic_local/api/api.py", line 146, in async_send_and_receive
    resp = await protocol.async_send_and_receive(message_type, message)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/pyomnilogic_local/api/protocol.py", line 336, in async_send_and_receive
    return self._decode_payload(raw_data, compressed)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/pyomnilogic_local/api/protocol.py", line 287, in _decode_payload
    data = zlib.decompress(data.rstrip(b"\x00"))
zlib.error: Error -5 while decompressing data: incomplete or truncated stream

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 434, in _async_refresh
    self.data = await self._async_update_data()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/config/custom_components/omnilogic_local/coordinator.py", line 51, in _async_update_data
    raise UpdateFailed("Failed to update data from OmniLogic") from err
homeassistant.helpers.update_coordinator.UpdateFailed: Failed to update data from OmniLogic
2026-06-19 21:56:32.680 DEBUG (MainThread) [custom_components.omnilogic_local.coordinator] Finished fetching OmniLogic data in 0.026 seconds (success: False)

Another user reported this issue in the HA forums and posted an AI analysis with proposed patch here: https://community.home-assistant.io/t/hayward-pools-local-integration-announcement/584634/16. I can confirm that this patch makes the problem go away, although I struggle to see why it would make a difference:

--- api/protocol.py_orig
+++ api/protocol.py
@@ -284,7 +284,9 @@
             Decoded UTF-8 string with leading/trailing null bytes stripped.
         """
         if compressed:
-            data = zlib.decompress(data.rstrip(b"\x00"))
+            # data = zlib.decompress(data.rstrip(b"\x00"))
+            _d = zlib.decompressobj()
+            data = _d.decompress(data.rstrip(b"\x00")) + _d.flush()
         return data.decode("utf-8").strip("\x00")

I would (and can) provide a PR but I am not super comfortable in not understanding why this is intermittently failing or why this fix works. Happy to help with debug if needed.