http2: changes in error handling

[icing]

• always treat errors from nghttp2_session_mem_recv() as fatal
• always return 0 from invalid_frame callback, so that nghttp2's internal RST/GOAWAY handling can work
• adjust test_01_14 return code expectation

[icing]

@vszakats the Windows errors are caused by some cmake related change, maybe?

[Copilot]

🔵 Needs a closer look

It changes core HTTP/2 error/callback semantics with nghttp2, which can have subtle protocol/connection behavior impacts that should be validated by a maintainer with full test coverage.

Pull request overview

This PR adjusts libcurl’s HTTP/2 (nghttp2) error-handling behavior to treat nghttp2_session_mem_recv() errors as fatal, to always return success from the invalid_frame callback so nghttp2 can perform its own RST/GOAWAY handling, and aligns an HTTP/2 test expectation with the resulting exit code.

Changes:

• Change the nghttp2_session_mem_recv() error path in h2_process_pending_input() to return CURLE_RECV_ERROR.
• Make cf_h2_on_invalid_frame_recv() always return 0 (success) instead of NGHTTP2_ERR_CALLBACK_FAILURE.
• Update test_01_14_gigalarge_resp_headers to expect exit code 56 (CURLE_RECV_ERROR) for HTTP/2.

File summaries

File	Description
lib/http2.c	Updates HTTP/2 receive/error callback handling to change fatality and allow nghttp2 internal recovery signaling.
tests/http/test_01_basic.py	Updates HTTP/2 test expectation to match the new error code surfaced by the changed receive path.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite

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[vszakats]

@vszakats the Windows errors are caused by some cmake related change, maybe?

The Cygwin fail seen today looks like upstream temporary breakage. Let's see if it resolves itself.

[icing]

@vszakats the Windows errors are caused by some cmake related change, maybe?

The Cygwin fail seen today looks like upstream temporary breakage. Let's see if it resolves itself.

It did. Thanks for checking.