`strip_output_terminator` stripped `\r?\n$`, and a carriage return is as
legal a byte in a POSIX directory name as a newline is. For a repository
rooted at a directory named `trailing\r`, `rev-parse --show-toplevel`
prints the path's own `0d` and then its own `0a` terminator, and a strip
tolerant of an optional preceding carriage return cannot tell those two
bytes apart --- so it took both. The root resolved as `trailing`, and
every command afterwards ran with a `-C` and a cwd naming a directory
that does not exist: the same defect the previous commit at this call
site fixed, one byte over.
Exactly one trailing `\n` is now removed, by an explicit last-byte test
rather than an anchored pattern. Both of this function's bugs lived in a
pattern, and the third answer to the same question should not be a
cleverer one.
`-z` was CHECKED against the installed git rather than assumed, and must
NOT be used. `git rev-parse` has no `-z` option at all on git 2.55: it
is absent from the manual, `--parseopt -z` errors with "unknown switch",
and in ordinary mode `rev-parse` treats `-z` as an unrecognized flag
argument and echoes a literal `-z\n` onto stdout AHEAD of the toplevel
--- exit code 0, corrupted output, silent. `--show-toplevel` applies no
C quoting either, not even under `core.quotePath=true`. There is
therefore no unambiguous output representation to prefer over removing
the one byte git appended.
`first_line` is untouched, for the reason the previous commit recorded:
its three callers all feed the single-line status band, where taking the
first line is right.
Witnessed by `g6_14d` end to end, not at the parser: the fixture really
creates directories named `trailing\r` and `nl\nand-trailing\r`, the
real `git` resolves them, and the assertion is on the cwd of the status
spawn the module actually made, plus real rows in the panel and a RET
that opens the file the row names. The second case sends both hazards in
together because a root may hold both and neither fix may mask the
other. `g6_14c` now reaches that chain through the shared
`assert_root_resolves_whole` rather than keeping a second copy of it,
and the helper binds `pmacs.project.set_search_boundary` to the fixture
through `open_panel` --- R8's lesson, and a root fixture is exactly that
hazard's shape.
Mutation-verified: restoring `\r?\n$` fails `g6_14d` at `<tmp>/trailing`
against `<tmp>/trailing\r` while `g6_14c` still passes, which is exactly
the byte that separates the two fixes.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
39ad43db5a