Log the dropped request, and scope the receipt sentence to a reconnect

README.md

@@ -356,8 +356,9 @@ under it, the peer never answered in time, or you aborted it after it went out.
 where a drop ends the session and every send after it is refused.
 
 An answer cannot wait for a link that way, because it carries the sequence number the message arrived
-on: `sms.sendResp()` on a message whose link dropped writes nothing and returns an `err`. Its
-`sms.sendDlr()` still goes out, since a receipt is a request of its own, correlated by the id it names.
+on: `sms.sendResp()` on a message whose link dropped writes nothing and returns an `err`. Where a
+reconnect follows, its `sms.sendDlr()` still goes out on the new link, since a receipt is a request
+of its own, correlated by the id it names.
 
 `responseTimeout` bounds the wait for a link and the wait for an answer separately, and a send also
 queues for a `maxOutstanding` slot, which nothing bounds — so it is not a deadline for the call.
@@ -398,7 +399,8 @@ The spec tables are exported both individually (`cmds`, `consts`, `encodings`, `
 - **`server()` resolves once, when it is listening**, and gives you a handle with `close()`, `port`
   and a `session` event. It no longer calls your callback once per incoming connection.
 - **The id a message is answered with goes to `sendResp({ smsId })`**, and `sms.smsId` is read-only:
-  it reports the id `sendResp()` was given, or the UUID v7 generated instead. Delete any `sms.smsId = …` line — assigning to it
+  it reports the id `sendResp()` was given, or the UUID v7 generated instead. Delete any
+  `sms.smsId = …` line — assigning to it
   throws a `TypeError`, since modules are always strict mode — and pass the id to `sendResp()`.
 - **`checkuserpass` is now `authenticate`**, takes `{ password, session, systemId, systemType }` and
   returns `false` or `{ userData }`.

src/incoming-requests.ts

@@ -68,7 +68,11 @@ export class IncomingRequests {
 		if (this.onRequest && await this.onRequest(this.session, pduObj)) return;
 
 		// The link it arrived on went while the hook ran, so nothing we answer now correlates.
-		if (this.linkGeneration !== generation) return;
+		if (this.linkGeneration !== generation) {
+			this.log.info('session - dropping a request whose link went', { cmdName: pduObj.cmdName });
+
+			return;
+		}
 
 		if (!this.session.bindAllows(pduObj.cmdName)) {
 			this.log.info('session - command the peer\'s bind direction does not carry', {

test/session-extras.test.ts

@@ -603,7 +603,6 @@ describe('reconnect', () => {
 		// A response is dispatched before `incomingPduObj`, so only the raw event sees one arrive.
 		peerOf(smpp).on('incomingPdu', () => { taken++; });
 
-		// The answered one is out of the hold and the held one is not, so neither may reach the answer.
 		assert.match((await answered.sendResp()).err?.message ?? '', /link this message arrived on is gone/);
 		assert.match((await held.sendResp()).err?.message ?? '', /link this message arrived on is gone/);
 
@@ -635,6 +634,10 @@ describe('reconnect', () => {
 		await handled;
 
 		assert.equal(messages, 0);
+
+		await incoming.handle(submitPdu(2));
+
+		assert.equal(messages, 1, 'the harness delivers a message whose link stayed');
 	});
 
 	test('does not reconnect after an explicit close', async t => {