[MarcZX10]

What

Map Windows writes to a pipe with no readers to EPIPE in both the native write path and vectored stdio transfer path. Add a guest regression test for the closed-pipe write behavior.

Tested

Linux: built guest_pipe_closed_write_tests; guest_pipe_closed_write passed (1/1). python3 tools/check_conventions.py --base upstream/main and git diff --check upstream/main passed. Windows-specific error mapping was not executed locally.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw; silent stubs listed under technical debt
• No notes, investigation .md files or images added to repository
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• Unblocks: none
• GPUs tested: n/a
• AI-assisted: yes
• Tested on Windows: no

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
#5008	core/libs/prx/libkernel/CMakeLists.txt L1250

[LeandroLP23]

Windows check, since this is a Windows-only remap. Setup: Windows 11 (26300), WinLibs GCC 15.2.0, Release, head e0f0350a5 merged onto main 30f961266.

• With the PR: guest_pipe_closed_write passes.
• With main's File/src/Open.cpp and File/src/Stdio.cpp and the PR's test: it fails. The test's Require aborts (FATAL: abort() (SIGABRT), exit 0xc0000409), so a write to a pipe whose reader is closed does not give EPIPE there.

AI-assisted: yes (Claude Code)

[MarcZX10]

Thanks for the Windows control run. The focused test passes with this change and fails with the main source files, which gives useful independent confirmation of the EPIPE path on Windows.

[oneandonlydean]

Closing: no title is known to reach this. With the queue at 700+ open PRs, please hold off on new PRs that don't name a title needing the change until it's down. If a title stops on this on current main, reopen with the title ID and the log line.