Drop an assertion that always passes, and reflow a decision

docs/decisions.md

@@ -434,11 +434,10 @@ rule and an index of the titles below.
   `writeParams()` ignores it, so an empty one, an absent one and one the wire cannot carry are the
   same input rather than three. A `data_coding` on a command that declares no such field is honoured
   the other way round, since it is `replace_sm`'s only way to name the alphabet its octets are in.
-  Rejected: refusing a string
+  Rejected: refusing a string `message_payload` outright and demanding octets, which contradicts
-  `message_payload` outright and demanding
+  `short_message` on the same PDU. Rejected: guarding every string-valued field against
-  octets, which contradicts `short_message` on the same PDU. Rejected: guarding every string-valued
+  `data_coding`, which says nothing about them — a text field on the wire has an alphabet of its
-  field against `data_coding`, which says nothing about them — a text field on the wire has an
+  own.
-  alphabet of its own.
 
 - **A GSM 03.38 message declares `data_coding` 0x00, and an inbound 0x01 is still read as GSM.**
   Maintainer's call, 2026-09-09: `dataCodingFor()` and `encodeBody()` both resolved an alphabet

test/pdu.test.ts

@@ -554,7 +554,7 @@ describe('TLVs', () => {
 		assert.deepEqual([id, state, unknown], ['0199d8a4-5e2c-7b3f-9a61-c4e07f2d8b15', 2, Buffer.from('01', 'hex')]);
 
 		// @ts-expect-error an octet field takes no number, which would go out as its digits
-		assert.ok(objToPdu({ cmdName: 'deliver_sm', params: {}, tlvs: { network_error_code: { tagValue: 5 } } }));
+		objToPdu({ cmdName: 'deliver_sm', params: {}, tlvs: { network_error_code: { tagValue: 5 } } });
 		// @ts-expect-error message_state is an integer
 		assert.ok(objToPdu({ cmdName: 'deliver_sm', params: {}, tlvs: { message_state: { tagValue: 'ENROUTE' } } }).err);
 	});