🐛 Bug Report: http --download misinterprets Content-Length when Content-Encoding: gzip is set

Bắt đầu bằng cách tái hiện sự cố với lệnh http --download GET được cung cấp và kiểm tra cách HTTPie xử lý việc tải xuống. Kiểm tra cách Content-Length và Content-Encoding: gzip được diễn giải, sau đó xác minh rằng payload đã nén được lưu mà không phát sinh lỗi tải xuống không hoàn tất và hành vi tải xuống hiện tại vẫn được giữ nguyên.

🐛 Bug Report: http --download misinterprets Content-Length when Content-Encoding: gzip is set

Summary

When using httpie with --download to retrieve a file with Content-Encoding: gzip, the tool reports an "Incomplete download" even though the Content-Length is correctly set to the size of the compressed payload.

This behavior contradicts the HTTP/1.1 spec, which states that Content-Length must reflect the encoded (compressed) size when Content-Encoding is used.

Steps to Reproduce

1. Serve a GZIP-compressed JSON file with these headers:

Content-Type: application/json
Content-Encoding: gzip
Content-Disposition: attachment; filename="data.json.gz"
Content-Length: 5084527  # actual size of compressed content

2. Use HTTPie to download the file:

http --download GET http://localhost:3000/download

3. Observe this error:

Incomplete download: size=5084527; downloaded=42846965

Note: The server is not using chunked encoding and Content-Length is accurate.

Expected Behavior

httpie should:

• Trust Content-Length as the size of the compressed body.
• Simply save the file without decompressing or misinterpreting the length.

This is what browsers, curl, and wget all do correctly.

Actual Behavior

httpie seems to assume Content-Length is the uncompressed size, leading it to flag the download as incomplete when it receives more data than expected.

Environment

• HTTPie version: httpie 3.2.4
• OS: macOS / Linux (reproduced in both)
• Server: Custom Go server (Fiber), but same issue with static gzipped files

References

• [RFC 9110 § 8.6](https://www.rfc-editor.org/rfc/rfc9110#section-8.6):

  “The Content-Length field indicates the number of octets in the body of the message after any content codings have been applied.”

Debug Info

http get "localhost:3000/metrics/admin/00:11:00:00:22:00/20250101T000000Z/download?format=json" Authorization:"Bearer ey....." --download --debug
HTTPie 3.2.4
Requests 2.32.4
Pygments 2.19.1
Python 3.13.5 (main, Jun 11 2025, 15:36:57) [Clang 17.0.0 (clang-1700.0.13.3)]
/opt/homebrew/Cellar/httpie/3.2.4_3/libexec/bin/python
Darwin 24.5.0

<Environment {'apply_warnings_filter': <function Environment.apply_warnings_filter at 0x10665cd60>,
 'args': Namespace(),
 'as_silent': <function Environment.as_silent at 0x10665cc20>,
 'colors': 256,
 'config': {'default_options': []},
 'config_dir': PosixPath('/Users/alex/.config/httpie'),
 'devnull': <property object at 0x106642110>,
 'is_windows': False,
 'log_error': <function Environment.log_error at 0x10665ccc0>,
 'program_name': 'http',
 'quiet': 0,
 'rich_console': <functools.cached_property object at 0x105a0e690>,
 'rich_error_console': <functools.cached_property object at 0x106630c00>,
 'show_displays': True,
 'stderr': <_io.TextIOWrapper name='<stderr>' mode='w' encoding='utf-8'>,
 'stderr_isatty': True,
 'stdin': <_io.TextIOWrapper name='<stdin>' mode='r' encoding='utf-8'>,
 'stdin_encoding': 'utf-8',
 'stdin_isatty': True,
 'stdout': <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>,
 'stdout_encoding': 'utf-8',
 'stdout_isatty': True}>

<PluginManager {'adapters': [],
 'auth': [<class 'httpie.plugins.builtin.BasicAuthPlugin'>,
          <class 'httpie.plugins.builtin.DigestAuthPlugin'>,
          <class 'httpie.plugins.builtin.BearerAuthPlugin'>],
 'converters': [],
 'formatters': [<class 'httpie.output.formatters.headers.HeadersFormatter'>,
                <class 'httpie.output.formatters.json.JSONFormatter'>,
                <class 'httpie.output.formatters.xml.XMLFormatter'>,
                <class 'httpie.output.formatters.colors.ColorFormatter'>]}>

>>> requests.request(**{'auth': None,
 'data': RequestJSONDataDict(),
 'headers': <HTTPHeadersDict('User-Agent': b'HTTPie/3.2.4', 'Authorization': b'Bearer eyJh...', 'Accept-Encoding': b'identity')>,
 'method': 'get',
 'params': <generator object MultiValueOrderedDict.items at 0x106a7d030>,
 'url': 'http://localhost:3000/metrics/admin/00:11:00:00:22:00/20250101T000000Z/download?format=json'})

HTTP/1.1 200 OK
Content-Disposition: attachment; filename="001100002200-20250101T000000Z.alog.json.gzip"
Content-Encoding: gzip
Content-Length: 5084527
Content-Type: application/json
Date: Thu, 10 Jul 2025 16:22:21 GMT

Downloading to 001100002200-20250101T000000Z.alog.json.gzip
Done. 42.8 MB in 00:0.07174 (597.2 MB/s)

http: error: Incomplete download: size=5084527; downloaded=42846965