refactor(airc): _reexec_into helper consolidates 5 exec sites (#205 target 1, net -21)

[joelteply]

Net-negative diff: -21 lines

Additions	25
Deletions	46
Net removed	21
airc.sh size	5469 → 5448

What changed

Five cmd_connect sites previously duplicated the same 3-line pattern:

local _preserved_name; _preserved_name=$(get_config_val name "")
_write_reexec_marker
exec env [AIRC_NO_DISCOVERY=1] ${_preserved_name:+AIRC_NAME=$_preserved_name} "$0" connect <args>

Plus 3 inline comment paragraphs explaining what each exec did (also duplicated).

After: one _reexec_into <mode> <args> helper, mode ∈ {rejoin, host}. Five call sites collapse to one line each. The standalone _write_reexec_marker function (11-line block comment + 4-line body, only one logical caller after this) is folded into the helper.

Behavior

Unchanged. Same env vars passed the same way, same exec arguments, same marker file written. Verified:

• syntax clean (bash -n airc)
• all 5 call sites still re-exec into the same mode (rejoin vs host) with the same args
• marker file path identical ($AIRC_WRITE_DIR/airc.reexec-marker) so fix(airc daemon): sentinel-marker for intentional re-exec on Windows (#203) #204's forfiles check in the daemon launcher .bat keeps working

Bonus side-effect

Pre-fix, every new exec site was a fresh chance to forget the _write_reexec_marker call — which is exactly what triggered #203 (the daemon crashloop). Post-fix, the only way to re-exec is _reexec_into, which always writes the marker. Future fix sites can't regress.

#205 progress

Target 1 of 6 ✅. Authenticator-fd63 owns target 3 in parallel. Combined target 1+3 should land ~50 lines net negative.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Refactors airc connect self re-exec flows by consolidating repeated “write marker + preserve name + exec env … connect …” patterns into a single _reexec_into helper, keeping Windows daemon re-exec sentinel behavior intact (#203/#204) while reducing duplication as part of #205.

Changes:

• Introduces _reexec_into <mode> ... to centralize marker writing, name preservation, and host takeover env (AIRC_NO_DISCOVERY=1).
• Replaces five duplicated exec call sites in cmd_connect with one-line _reexec_into calls.
• Trims duplicated daemon-launcher marker commentary to reference the new helper.

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[Copilot]

_reexec_into passes AIRC_NAME to env via an unquoted parameter expansion. If the configured name ever contains whitespace/shell metacharacters, this will split into multiple args (the embedded quotes in AIRC_NAME="$_name" are literal characters and do not prevent word-splitting). Build an env argv array (as done in spawn_general_sidecar_if_wanted) and exec env "${env_args[@]}" ... to make this quoting-safe.

Suggested change

	if [ "$mode" = "host" ]; then
	exec env AIRC_NO_DISCOVERY=1 ${_name:+AIRC_NAME="$_name"} "$0" connect "$@"
	else
	exec env ${_name:+AIRC_NAME="$_name"} "$0" connect "$@"
	fi
	local -a env_args=()
	if [ "$mode" = "host" ]; then
	env_args+=(AIRC_NO_DISCOVERY=1)
	fi
	if [ -n "$_name" ]; then
	env_args+=("AIRC_NAME=$_name")
	fi
	exec env "${env_args[@]}" "$0" connect "$@"

[Copilot]

_reexec_into silently treats any mode other than host as the rejoin path. Since the function contract/comment says mode is rejoin|host, consider validating mode (including missing $1) and failing fast on unexpected values to avoid accidental behavior changes when adding new call sites.