6643cd87

test: a piped mux hands back the shell's own exit code

a73x 2026-08-28 19:53

Commit message

test: a piped mux hands back the shell's own exit code

The invariant says a piped `mux` exits with the shell's status because
scripts read it, and every pipe_waitexit in the suite but one wanted the
default 0 — which a client that invented its own code satisfies just as
well. The session-a lifetime leg now exits 7.

test/e2e_05_session.sh

Old		New
@@ -142,9 +142,16 @@ fi
142	# every one of those deaths (decision 8). This client attaches to a session	142	# every one of those deaths (decision 8). This client attaches to a session
143	# that ALREADY EXISTS — attach-or-create's join arm, the other half of the	143	# that ALREADY EXISTS — attach-or-create's join arm, the other half of the
144	# two creations above — and types the exit that ends it.	144	# two creations above — and types the exit that ends it.
		145	#
		146	# `exit 7`, not `exit`: a PIPED mux is a wall of one and hands the shell's
		147	# own status back, because scripts read it. Every other pipe_waitexit in
		148	# this suite wants the default 0, which a client that invented its own code
		149	# would satisfy just as well; seven is a number only the shell can be the
		150	# source of. (128 is pinned too, on a SIGKILLed shell, in the hosts group —
		151	# this is the ordinary path.)
145	pipe_mux "$OUT.m18ax" "$OUT.m18ax.err" timeout 40 "$MUX" --sock "$SOCK21" --session a	152	pipe_mux "$OUT.m18ax" "$OUT.m18ax.err" timeout 40 "$MUX" --sock "$SOCK21" --session a
146	pipe_send 'exit\n'	153	pipe_send 'exit 7\n'
147	pipe_waitexit "M18: the client of an exiting session"	154	pipe_waitexit "M18: a piped mux carries the shell's own exit code" 7
148		155
149	wait_sessions "$SOCK21" 2 "M18: session a's shell exited"	156	wait_sessions "$SOCK21" 2 "M18: session a's shell exited"
150		157