LocalProtocolError: Too little data for declared Content-Length

[galaxyproject-sentryintegration]

Sentry Issue: GALAXY-MAIN-4KSCZZZ00156S

ExceptionGroup: unhandled errors in a TaskGroup
  File "starlette/_utils.py", line 79, in collapse_excgroups
    yield
  File "starlette/responses.py", line 270, in __call__
    async with anyio.create_task_group() as task_group:
  File "anyio/_backends/_asyncio.py", line 783, in __aexit__
    raise BaseExceptionGroup(

LocalProtocolError: Too little data for declared Content-Length
(26 additional frame(s) were not displayed)
...
  File "galaxy/webapps/galaxy/fast_app.py", line 136, in __call__
    await self.app(scope, receive, send_with_header)
  File "galaxy/webapps/galaxy/fast_app.py", line 134, in send_with_header
    await send(message)

[dannon]

Triage: Bug (Sentry) | Severity: Medium | Effort: Small (fix exists)

The proxy endpoint's _filter_response_headers() only strips content-length when upstream used content-encoding (compression), but the stream can also be truncated by MAX_STREAM_BYTES (1 MB) or MAX_STREAM_SECONDS (10s) limits on uncompressed responses, causing a mismatch. Uvicorn's h11 layer then raises LocalProtocolError.

PR #22314 by @mvdbeek already fixes this by unconditionally stripping content-length and accept-ranges from streamed responses. Same bug class as #21152 / PR #21169 which only fixed the compressed case.

Full analysis: https://gist.github.com/dannon/25a9979bd9cc08bcf5d8ed3b8492d927