split: fix I/O error handling for device full conditions

[sylvestre]

Should fix tests/split/split-io-err.sh

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/io-errors. tests/misc/io-errors is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/split/filter. tests/split/filter is passing on 'main'. Maybe you have to rebase?
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tty/tty-eof (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/rm/many-dir-entries-vs-OOM is now passing!
Congrats! The gnu test tests/tail/pipe-f is now passing!

[codspeed-hq]

Merging this PR will degrade performance by 17.56%

❌ 3 regressed benchmarks
✅ 294 untouched benchmarks
⏩ 48 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	split_bytes	429.2 µs	463.3 µs	-7.36%
❌	Simulation	split_lines	5.6 ms	6.8 ms	-17.56%
❌	Simulation	split_numeric_suffix	5.9 ms	7.1 ms	-16.93%

---

_{Comparing sylvestre:split-io (b1028c8) with main (ff6dd99)}

Footnotes

1. 48 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/split/filter. tests/split/filter is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/split/split-io-err is no longer failing!
Note: The gnu test tests/tail/tail-n0f is now being skipped but was previously passing.
Congrats! The gnu test tests/rm/many-dir-entries-vs-OOM is now passing!
Congrats! The gnu test tests/tail/pipe-f is now passing!

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/split/filter. tests/split/filter is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/date/resolution (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/split/split-io-err is no longer failing!
Note: The gnu test tests/printf/printf-surprise is now being skipped but was previously passing.
Congrats! The gnu test tests/expand/bounded-memory is now passing!

[kevinburkesegment]

I was looking at implementing the same patch - what do you think, did you avoid merging this because of the performance concerns?

[cakebaker]

I would split this function into two functions to avoid the Option for error_context and the if let conditions in the function.