head: propagate a write error from the -v filename header - #13996
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head: propagate a write error from the -v filename header#13996MsfPablo wants to merge 3 commits into
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The two header writes around it use ?, but the filename went out via print_verbatim(file).unwrap(). A short name stays buffered and its error surfaces later at the checked flush; a name longer than the stdout buffer forces a flush mid-write, so the failure lands in the unwrap and aborts instead of being reported. Fixes uutils#13264
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| /// Regression for #11972: a symlink that points to a regular file must | ||
| /// still be readable by head (the fd-based check must distinguish the | ||
| /// fd's mode, not the symlink's). |
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August 19, 2026 17:16
Move the uutils#13887 verbose-header write-error regression test to after test_head_follows_symlink_to_regular_file so the uutils#11972 doc comment stays attached to the test it documents (review feedback).
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Fixes #13264.
print_verbatim(file).unwrap()was the only unchecked write inprint_header— the==>and<==around it already use?. Switched it to?so the error travels the same way.The length threshold in the issue is what makes this reachable: a short filename stays in the stdout buffer and its write error surfaces later at a
?-checked flush, so only a name longer than the buffer forces a flush inside theunwrap.Now reports the write error and exits 1 instead of aborting.
Tests: an integration test following the
/dev/fullpattern already used intest_paste.rs, gated to Linux for the same reason.Worth being upfront: I develop on macOS, where
/dev/fullis not writable, so I could not execute that test locally. I did verify it compiles and runs by temporarily widening thecfg— it reaches the/dev/fullopen and fails only there — so CI is the real check on the assertion.