fix(wake): #942 follow-up — whole-string knob validation; grep line anchors admit multi-line values

mos-dt's post-verdict residual (non-blocking, comments 19484/19487): grep is
LINE-oriented, so ^[0-9]{1,9}$ binds per line and a knob with an embedded
newline ($'300\n8', $'300\nabc') passes the regex whole yet is FATAL inside
$((...)) under set -u — the same poll-killing class #942 fixed, reachable only
via the env-config operand (snap_ts is immune: jq's number type-check cannot
emit an embedded newline).

Fix (mos-dt-verified pattern): replace grep with a whole-string case pattern —
'' and *[!0-9]* reject, length <= 9 — identical accept/reject to the regex on
every single-line value, rejects both multi-line cases. 10# radix force
unchanged. Two new D13 sub-cases (SHA-CC2/SHA-CC3) cover exactly the repros;
det_seq assertion 6 -> 8. Manifest states the string-extent rule: the validator
and the consumer must agree on STRING EXTENT, not just shape and radix.

Suite: 13 groups, D13 green 4/4 local runs; sole intermittent failure is the
known pre-existing D4 fd-9 flake (carried separately by mos-dt).

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01NsKce8iZuSuRnu3gVMCBKB

packages/mosaic/framework/tools/wake/detector.sh

@@ -295,16 +295,24 @@ _poll_source() {
         # is interpolated into $((...)) under set -u, so a non-numeric value
         # ('300s', '5m', 'abc') would be FATAL to the poll — the one thing this
         # block must never be. Resolve it ONCE, validate, fall back loudly.
-        local now_s slack
+        local now_s slack slack_ok
         slack="${WAKE_SNAPSHOT_TS_FUTURE_SLACK:-300}"
-        if ! printf '%s' "$slack" | grep -Eq '^[0-9]{1,9}$'; then
+        # NOT grep: grep is LINE-oriented, so ^...$ anchors bind per line and a
-          echo "detector.sh: WAKE_SNAPSHOT_TS_FUTURE_SLACK='$slack' is not a plain non-negative integer (seconds) — falling back to 300, poll continues (#940)." >&2
+        # multi-line value ($'300\n8') passes the regex yet is FATAL in $((...)).
+        # The case pattern matches the WHOLE string, newlines included. (snap_ts
+        # is immune: jq's number type-check above cannot emit an embedded newline.)
+        case "$slack" in
+        '' | *[!0-9]*) slack_ok=1 ;;
+        *) [ "${#slack}" -le 9 ] && slack_ok=0 || slack_ok=1 ;;
+        esac
+        if [ "$slack_ok" -ne 0 ]; then
+          echo "detector.sh: WAKE_SNAPSHOT_TS_FUTURE_SLACK='$slack' is not a plain non-negative integer of at most 9 digits (seconds) — falling back to 300, poll continues (#940)." >&2
           slack=300
         fi
         # Shape validation is not radix validation: bash reads a leading zero as
-        # OCTAL, so '08'/'09' pass the regex yet are FATAL in $((...)), and
+        # OCTAL, so '08'/'09' pass the shape check yet are FATAL in $((...)), and
         # '0300' silently means 192. Force base-10 so the knob means what the
-        # operator wrote (safe: the regex above guarantees pure digits).
+        # operator wrote (safe: the case pattern above guarantees pure digits).
         slack=$((10#$slack))
         now_s="$(date +%s)"
         if [ "$snap_ts" -gt $((now_s + slack)) ]; then

packages/mosaic/framework/tools/wake/manifest.txt

@@ -276,15 +276,21 @@
 #              yields a NEGATIVE age — stale-reads-fresher-than-fresh, the
 #              exact failure class #940 fixes. The SLACK knob itself is
 #              operator input interpolated into arithmetic under set -u, so it
-#              gets the same discipline (#941 §2 round 2): validated
+#              gets the same discipline (#941 §2 round 2): shape-validated as
-#              ^[0-9]{1,9}$, else LOUD fallback to 300 — a malformed knob
+#              a plain non-negative integer of at most 9 digits, else LOUD
+#              fallback to 300 — a malformed knob
 #              ('300s', '5m', 'abc') must never kill the poll, and a negative
 #              one must never invert the guard into deny-all. Shape validation
 #              is NOT radix validation (#942 review): bash reads leading zeros
-#              as OCTAL, so '08'/'09' pass the regex yet are fatal in $((...))
+#              as OCTAL, so '08'/'09' pass the shape check yet are fatal in
-#              and '0300' silently means 192 — the knob is therefore forced
+#              $((...)) and '0300' silently means 192 — the knob is therefore
-#              base-10 (10#) after validation, so it means what the operator
+#              forced base-10 (10#) after validation, so it means what the
-#              wrote. SKEW GUARANTEE
+#              operator wrote. The validator and the consumer must also agree
+#              on STRING EXTENT (#942 follow-up): grep's ^...$ anchors bind
+#              per LINE, so a multi-line value ($'300\n8') passed the regex
+#              whole yet was fatal in $((...)) — validation is a whole-string
+#              case pattern, not grep, so an embedded newline rejects.
+#              SKEW GUARANTEE
 #              (stated, not implied): the future-skew check runs against the
 #              DETECTOR's clock; consumer-side age arithmetic runs on the
 #              consumer's. A surviving snapshot_ts is therefore attested only

packages/mosaic/framework/tools/wake/test-wake-detector.sh

@@ -644,6 +644,26 @@ EOF
   entry="$("$STORE" drain | tail -1)"
   echo "$entry" | jq -e --arg s "$goodsha" 'select(.locators.snapshot_sha==$s) | .locators | has("snapshot_ts")' >/dev/null 2>&1 \
     || fail_msg "D13: negative slack must NOT invert the guard into deny-all [$entry]"
+  # (c2) MULTI-LINE knobs — grep's ^...$ anchors bind PER LINE, so a value with
+  # an embedded newline ($'300\n8') passed the old regex whole yet is FATAL in
+  # \$((...)) ('error token is "8"'; $'300\nabc' dies as unbound variable). The
+  # case pattern matches the WHOLE string: both must fall back loudly, keep the ts.
+  printf '{"snapshot_sha":"%s","snapshot_ts":%s}\n' "$goodsha" "$(date +%s)" >"$stub/repo_r1.meta"
+  printf 'SHA-CC2\n' >"$stub/repo_r1"
+  err="$(WAKE_SNAPSHOT_TS_FUTURE_SLACK=$'300\n8' "$DET" poll-once 2>&1 >/dev/null)"; rc=$?
+  [ "$rc" -eq 0 ] || fail_msg "D13: multi-line SLACK (300\\n8) must NEVER fail the poll (rc=$rc) [$err]"
+  echo "$err" | grep -qi 'falling back to 300' || fail_msg "D13: multi-line slack must be LOUD on stderr [$err]"
+  entry="$("$STORE" drain | tail -1)"
+  echo "$entry" | jq -e --arg s "$goodsha" 'select(.locators.snapshot_sha==$s) | .locators | has("snapshot_ts")' >/dev/null 2>&1 \
+    || fail_msg "D13: valid metadata must SURVIVE a multi-line knob [$entry]"
+  printf '{"snapshot_sha":"%s","snapshot_ts":%s}\n' "$goodsha" "$(date +%s)" >"$stub/repo_r1.meta"
+  printf 'SHA-CC3\n' >"$stub/repo_r1"
+  err="$(WAKE_SNAPSHOT_TS_FUTURE_SLACK=$'300\nabc' "$DET" poll-once 2>&1 >/dev/null)"; rc=$?
+  [ "$rc" -eq 0 ] || fail_msg "D13: multi-line SLACK (300\\nabc) must NEVER fail the poll (rc=$rc) [$err]"
+  echo "$err" | grep -qi 'falling back to 300' || fail_msg "D13: multi-line non-numeric slack must be LOUD on stderr [$err]"
+  entry="$("$STORE" drain | tail -1)"
+  echo "$entry" | jq -e --arg s "$goodsha" 'select(.locators.snapshot_sha==$s) | .locators | has("snapshot_ts")' >/dev/null 2>&1 \
+    || fail_msg "D13: valid metadata must SURVIVE a multi-line non-numeric knob [$entry]"
   # (d2-pre) ZERO-PADDED knobs — shape-valid, radix-hostile. '08' passes the
   # regex but is fatal octal in \$((...)) without the 10# normalization; '0300'
   # silently means 192 (octal), so a ts +250s ahead would be WRONGLY dropped.
@@ -671,7 +691,7 @@ EOF
   entry="$("$STORE" drain | tail -1)"
   echo "$entry" | jq -e --arg s "$goodsha" 'select(.locators.snapshot_sha==$s) | .locators | has("snapshot_ts") | not' >/dev/null 2>&1 \
     || fail_msg "D13: valid SLACK=0 must drop the future ts but keep the sha [$entry]"
-  [ "$(det_seq)" = "6" ] || fail_msg "D13: all six real deltas must still have enqueued, got seq $(det_seq)"
+  [ "$(det_seq)" = "8" ] || fail_msg "D13: all eight real deltas must still have enqueued, got seq $(det_seq)"
 ) && ok
 
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