Rebased onto current next and composes the two sibling mechanisms per the
O1 ruling: the cursor-row draft transition stays the authoritative
runtime-agnostic delivered verdict; next's locate_input_box (two shapes:
prompt glyph, pi rule box) is adopted as positive DRAFT evidence only,
covering the cursor-row check's blind spot on redrawn TUIs that park the
cursor off the input line. Box-absence proves nothing and can never
produce UNDELIVERED: a shapeless-but-submitting pane delivers via the
cursor-row transition regardless.
The verdict suite gains fixtures 6 and 6b: the 2026-09-04 scratch probe
is the regression test (shapeless REPL that submits must report
delivered; shape probing alone exited 2 with retry advice on a consumed
message), plus the raw/no-echo shapeless guard arm. Measured limit
recorded in the suite: a shapeless cooked non-reading pane is
indistinguishable from a delivering one by any runtime-agnostic signal
available to the sender.
Rerun evidence: pipefail scanner 7/7, glyph-agnostic suite 6/6, verdict
suite 8/8, live shapeless probe rc=0 delivered with consumption proof.
pipefail-early-exit.test.mjs (static scan) flagged the fixture-2 check as a
pipe into an early-exiting consumer; the sibling at fixture 1 already uses
the herestring form. Red reproduced locally (one scan entry, exactly the
flagged line), green after matching the sibling; verdict 4/4 and glyph 6/6
re-run green.
- F5 (rev-code-02 blocker): sign test-send-message-glyph-agnostic.sh into
test-enumeration-exclusions.txt beside its tmux siblings; the CI image
ships no tmux, so the suite stays manually run (#1017 burndown).
- Adoption finding: the verdict suite hard-coded SEND to its sibling and
ignored the SEND env var, so a red-first run against the shipping blob
silently measured the patched copy instead (measured: shipping run
printed PASS=4; with SEND honored it is PASS=3 FAIL=1, fixture 2 red,
matching the recorded review numbers). SEND is now honored with the
sibling as default, same contract as the glyph suite.
- F6/D19: framework FLEET-COMMS.md claimed 'rc=2 is the normal result
when the target is an idle pi seat'. Post-fix rc=0 is normal for idle
and busy pi seats; rc=2 on a healthy seat is a real report. Never-retry
advice kept, softened to 'may be in the pane' for the unconfirmed arm.
Live verification on sb-it-1-dt (tmux 3.7b, pi glm-5.3 low, scratch
session): idle pi - shipping rc=2 'may be UNDELIVERED' while the seat
consumed the message and answered; patched rc=0 delivered, answered.
Busy pi mid-turn - shipping rc=2 while the pane accepted both messages
as steering input ('Steering: ...', 'Alt+Up to edit all queued
messages'); patched rc=0 delivered, both consumed and acted on after the
turn. Both D11 signatures: verdict now matches reality.
send-message.sh located the REPL input box with grep -E '❯|^>|│ >'. That set is
Claude Code's box. A pi seat renders a bare U+2500 rule with no glyph, so on every
idle pi seat the capture succeeded, the grep matched nothing, status stayed
"unconfirmed", and the tool exited 2 "may be UNDELIVERED" with the paste and the
Enter both landed. The stderr tells the operator to retry, and that retry is the
duplicate delivery reported against the same tool.
Confirmation is now runtime-agnostic: our message tail sits on the input line
(located by cursor row, no glyph) before Enter and has left it after. That
transition is positive proof of submission.
Absence still proves nothing, which is the guard the 2026-08 fix was reaching for
and got backwards. Two positive checks keep it:
- a prompt box that IS locatable and still carries our tail => draft, exit 2.
This covers the cursor-row blind spot: a cooked pane whose foreground process
never reads stdin echoes the paste through the kernel line discipline and
moves the cursor off it on Enter, which by cursor row alone is indistinguishable
from a real submit.
- no draft ever observed on the input line => unconfirmed, non-zero.
Tests, both red-first against the shipping blob d397907:
test-send-message-glyph-agnostic.sh (new, 6 fixtures) 4/6 -> 6/6
test-send-message-verdict.sh (fixture 2 reshaped, 2b added) 3/4 -> 4/4
Fixture 2 of the verdict suite asserted exit 2 for a glyphless pane that submits
and was labelled "false-positive FIXED". A pi seat is that fixture, so the suite
was locking the bug in. It is reshaped deliberately, and the guard it was credited
with moves to new fixture 2b (glyphless AND non-submitting, raw/no-echo) so the
"never infer delivered from absence" property is tested positively rather than as
a side effect.
Measured on tmux 3.7b (sb-it-1-dt), 3.5a (fomo-lin), and dragon-lin.
Co-authored-by: scooby <[email protected]>
code-infra-01
orch-01
marcieandorch-01
jason.woltje
fred