Home Original page

Issue-3364: Reproduction + fix(Proposal ) by rajanyadav0307 · Pull Request #3693 · aws/aws-sdk-cpp

Issue #, if available:

Issue-3364: Fix Proposal

Description of changes:

This PR fixes an issue in CurlHttpClient::WriteData where querying the output position of the response body stream could cause the HTTP transfer to abort when the stream does not support positioning (e.g., boost::iostreams::filtering_stream with compression/decompression filters).

Problem

The existing implementation attempted to query the current write position of the response body stream using positioning APIs (tellp() / seek operations) for diagnostic purposes. For non-seekable output streams, this operation may fail and set the stream into a bad state, which caused the SDK to treat the write as a fatal error and abort the transfer, even though the actual write() operation itself was valid and succeeded.

This behavior is expected for certain stream types and should not be treated as a write failure.

Fix

  • Avoid treating unsupported output position queries as fatal errors.
  • Introduce a best-effort, non-intrusive position probe that detects whether the stream supports positioning without modifying stream state.
  • Preserve existing behavior for seekable streams while allowing non-seekable streams to function correctly.
  • Continue using the existing byte counter (m_numBytesResponseReceived) for accurate response size tracking.

This change improves compatibility with clients that use non-seekable or filtering output streams without altering public APIs or behavior for existing seekable stream use cases.

Check all that applies:

  • Did a review by yourself.
  • Added proper tests to cover this PR.
    (Added a regression test guarded by ENABLE_HTTP_CLIENT_TESTING that validates non-seekable response streams do not abort transfers. This follows the existing CurlHttpClient test pattern and requires the local dummy HTTP server for execution.)
  • Checked if this PR is a breaking (APIs have been changed) change.
  • Checked if this PR will not introduce cross-platform inconsistent behavior.
  • Checked if this PR would require a ReadMe/Wiki update.

Platforms verified:

  • Linux
  • Windows
  • Android
  • MacOS
  • IOS
  • Other Platforms

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Sign-off:
Rajan Y. (rajanyadav0307@gmail.com)