A remote host whose login shell is tcsh came up on 1.48.0, when the local
sh rewrote ${SHELL:-/bin/sh} to the Codeman host's shell. Since #770 the
launch reaches the far end verbatim and runs tcsh itself, and tcsh refuses
-i -l -c, -l -c and -i -l, so every stock launch left a dead pane.
The login flags are now picked on the far end, in the shape of
loginShellArgs(): set -- -i -l, cleared for csh and tcsh, then
exec "${SHELL:-/bin/sh}" "$@". The text is one brace group, so
cd <path> && { ...; } still starts nothing when the cd fails. bsd-csh takes
every flag combination, csh is listed because it is tcsh on macOS and the BSDs.
The version probe keeps its one statement: the login shell parses it, not
/bin/sh, so fish and tcsh refuse it either way, as they did on 1.48.0.
Measured with the real builder on a real sshd in a throwaway Debian container
(tcsh 6.24.07, bsd-csh, fish 3.6, bash) and through a fake sshd with
tcsh 6.24.10, fish, zsh, dash and bash, a real Codeman server on tcsh included.
The tcsh disclosure comes out of the docs and the changeset. They keep the two
limits 1.48.0 had too: tcsh has no export, so the PATH bootstrap only prints an
error, and the tmux probe needs a command executable, which Debian lacks.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Handing the launch to bash verbatim exposed `"${SHELL:-/bin/sh}"` to the far
end for the first time. tmux runs a one-argument command through the remote
default-shell, not /bin/sh as the comments said, and fish refuses `${...}`:
on a fish host, or a bash login with `set -g default-shell fish`, every new
pane died with status 127. master only survived because the local sh had
already rewritten that token to this host's shell path.
Codeman's own text now goes to `/bin/sh -c` as separate tmux arguments, which
tmux execs without a shell. A commands.* override stays one argument and keeps
the default-shell it was written for: under `/bin/sh` a `source` or `[[` in an
override dies with 127 on bash and zsh hosts.
The tests read the argv tmux would receive through a real sh, so they need no
fish: every stock launch must reach /bin/sh and an override must not. The
docker half of bashCArg was pinned by nothing, so it gets its own test.
Comments that described the removed double-quote layer are corrected, and
remote-hosts.ts no longer claims overrides are seeded from the default text
or that they rescue nushell and elvish.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>