Bug: Label_QP / Label_QR / Label_QS have no length guard on message.text — short messages emit empty ICAO airports, non-numeric time crashes MessageDecoder.decode()

[kevinelliott]

Summary

Label_QP, Label_QR, and Label_QS blindly slice message.text at fixed offsets with no length check. Two failure modes fall out of the same missing guard:

1. Silent-wrong-output: any text under 12 chars is fed straight to text.substring(0,4) / text.substring(4,8) / text.substring(8,12), so the plugin returns decoded: true with empty or truncated ICAO airport codes.
2. Crash: if chars 8-11 aren't numeric, convertHHMMSSToTod returns NaN, which reaches ResultFormatter.out → DateTimeUtils.timestampToString(NaN) → RangeError: Invalid time value, aborting the entire MessageDecoder.decode() call.

Location

• lib/plugins/Label_QP.ts:20-33
• lib/plugins/Label_QR.ts:20-33
• lib/plugins/Label_QS.ts:20-33

(Identical shape — same substring math with no length check.) Excerpt:

ResultFormatter.departureAirport(decodeResult, message.text.substring(0, 4));
ResultFormatter.arrivalAirport(decodeResult, message.text.substring(4, 8));
ResultFormatter.out(
  decodeResult,
  DateTimeUtils.convertHHMMSSToTod(message.text.substring(8, 12)),
);

Reproduction

Silent empty ICAO:

new MessageDecoder().decode({ label: 'QP', text: 'AA' });
// -> decoded: true, raw.departure_icao === 'AA', raw.arrival_icao === ''

Crash (garbage time field):

new MessageDecoder().decode({ label: 'QP', text: 'KSDLKLASABCD' });
// -> convertHHMMSSToTod('ABCD') -> NaN
// -> ResultFormatter.out -> timestampToString(NaN) -> RangeError
// -> escapes MessageDecoder.decode()

Impact

The empty-ICAO half is a silent-wrong-output pattern analogous to the empty-lat/lon (0,0) family (#487/#495/#497) but for airport codes; the crash half is a variant of the timestamp-family crash (filed alongside as a separate ResultFormatter issue). Both are reachable from a single unauthenticated ACARS input.

Suggested fix

Require the text to be at least 12 chars and the time field to be numeric before decoding; otherwise emit decodeLevel: 'none' / decoded: false. Applies identically to Label_QP, Label_QR, and Label_QS (and worth auditing Label_QQ variant-3 for the same pattern).