iOS: classify RR73 sign-off before grid so answered QSOs complete and log

ios/FT8AFKit/Sources/FT8Engine/QsoEngine.swift

@@ -286,14 +286,23 @@ func clampReport(_ snr: Int) -> Int { min(30, max(-30, snr)) }
 func fmtReport(_ n: Int) -> String { String(format: "%+03d", Int32(n)) }
 
 private func classify(_ msg: DecodedMessage) -> Content {
-    if !msg.grid.isEmpty { return .grid(msg.grid) }
+    // Recognize the QSO sign-offs before treating the message as a grid report.
+    // "RR73" is a valid 4-char Maidenhead-shaped token (R,R in A..R + two
+    // digits), so the decoder copies it into `grid` (looksLikeGrid("RR73") is
+    // true). Checking grid first would classify a partner's standard RR73
+    // sign-off as Content.grid, stranding the auto-sequencer at the RReport
+    // stage — it would retransmit our R-report forever and never complete/log
+    // the QSO. Matching the sign-offs first fixes that without touching
+    // looksLikeGrid (the map/distance code relies on its shape test). Mirrors
+    // the desktop (qso.rs) and Android (GeneralVariables) reference ports.
     let extra = msg.extra.trimmingCharacters(in: .whitespacesAndNewlines)
     switch extra {
     case "RR73": return .rr73
     case "RRR": return .rrr
     case "73": return .bye73
     default: break
     }
+    if !msg.grid.isEmpty { return .grid(msg.grid) }
     if extra.hasPrefix("R") {
         let rest = String(extra.dropFirst())
         if let n = Int(rest) { return .rReport(n) }

ios/FT8AFKit/Tests/FT8EngineTests/QsoEngineTests.swift

@@ -53,6 +53,42 @@ final class QsoEngineTests: XCTestCase {
         XCTAssertEqual(e.txMessage, "CQ K0XYZ EN37")
     }
 
+    func testRr73WithDecoderGridStillCompletesQso() {
+        // Regression for the sign-off-vs-grid classification bug (ported from
+        // desktop qso.rs `rr73_with_decoder_grid_still_completes_qso`). Live, the
+        // DX's RR73 arrives with grid == "RR73" because looksLikeGrid("RR73") is
+        // true and the decoder copies it into the grid field. If classify checked
+        // grid first it returned Content.grid, the RReport arm hit `default:
+        // break`, and the QSO hung retransmitting our R-report forever instead of
+        // logging.
+        let e = QsoEngine(myCall: "K0XYZ", myGrid: "EN37")
+        e.answer(msg("CQ", "K1ABC", "FN42", "FN42", -5))
+        _ = e.processRx([msg("K0XYZ", "K1ABC", "-12", "", -8)])
+        XCTAssertEqual(e.txMessage, "K1ABC K0XYZ R-08")
+        XCTAssertEqual(e.status().stage, .rReport)
+
+        // DX signs off with RR73 exactly as the decoder emits it live (grid set).
+        let out = e.processRx([msg("K0XYZ", "K1ABC", "RR73", "RR73", -8)])
+        guard case .completed(let rec)? = out else {
+            return XCTFail("RR73 sign-off must complete the QSO")
+        }
+        XCTAssertEqual(rec.call, "K1ABC")
+        XCTAssertEqual(rec.gridsquare, "FN42")
+        XCTAssertEqual(rec.rstSent, "-08")
+        XCTAssertEqual(rec.rstRcvd, "-12")
+        XCTAssertEqual(e.txMessage, "K1ABC K0XYZ 73")
+        XCTAssertEqual(e.status().stage, .bye73)
+
+        // A genuine 4-char grid reply is still classified as a grid, not a
+        // sign-off — the fix reorders the checks without weakening grid handling.
+        // As the CQ initiator, an answerer's grid must advance us to send a report.
+        let e2 = QsoEngine(myCall: "K0XYZ", myGrid: "EN37")
+        e2.startCq()
+        _ = e2.processRx([msg("K0XYZ", "K1ABC", "FN31", "FN31", -10)])
+        XCTAssertEqual(e2.txMessage, "K1ABC K0XYZ -10")
+        XCTAssertEqual(e2.status().stage, .report)
+    }
+
     func testInitiatorCqSequenceLogsQso() {
         let e = QsoEngine(myCall: "K0XYZ", myGrid: "EN37")
         e.startCq()