v0.4.9d — three playtest bugs: a train that looked gone, an unload that ignored the pick, a hang that wasn't one

Patched directly onto 0.4.9a rather than the in-progress 0.5.0 line.

A switching train vanished from the board the moment it left the Office. `selectedTrain` in
`officeSvg` (board-svg.ts), which gates whether a card draws a train's crew badge, was only ever
assigned inside the `cell.adTracks !== null` branch — true for the Office card alone. A train
standing anywhere else, which is everywhere it stands while actually being switched, drew no badge
at all. Game state was never affected; confirmed against the reported save with the engine directly.
Fix hoists the assignment out of the guard so it runs for any card with a train on it.

Unloading always took the westmost car, whichever one was picked. `laborer.beginUnload` carried the
player's chosen `carIndex`, and `check()` validated that specific car, but the `unloadBegan` event
it produced carried only the car's type — the reducer that performs the swap re-derived the target
with `industryTrack.cars.findIndex(c => c.loaded)`, which always answers the first loaded car in
track order regardless of what was requested. Fix adds `carIndex` to the event and uses it directly.

A legal decision could render with zero buttons, which looked exactly like a hang. The "where does
this Extra start" decision is titled by `trainCardTitle`, beginning "Making up Extra X22…" — the
same prefix `renderActions()` stripped from the action list on the assumption it only ever belonged
to the separate yard-chip car-placement panel. With no tray yet being filled, that panel is null, so
nothing rendered the Extra's decision either: a legal, correctly-computed option with no button
anywhere on the page. Replaying the reported save found no engine deadlock at any step — the engine
always had a move. Fix matches the exact title of the one group the yard-chip panel covers instead
of a title-prefix regex.

New tests for all three: a train parked on an ordinary facility card must draw its crew badge; three
differently-typed loaded cars, unloading index 2, must leave indices 0 and 1 alone; the existing
softlock regression test now mirrors the real render filter instead of only the raw menu, plus a
deterministic test for the exact reported scenario. 590 tests, 0 failures.

CHANGELOG.md

@@ -19,6 +19,81 @@ page as `v0.1.0 · <sha> · <date>`, so what is deployed can always be identifie
 
 ---
 
+## 0.4.9d — 2026-08-21
+
+Three bugs from the same playtest session, patched directly onto 0.4.9a rather than the in-progress
+0.5.0 line: a display bug that made a switching train look like it had vanished, an engine bug that
+silently ignored which car the player chose to unload, and a UI bug that could render a legal
+decision with zero buttons — indistinguishable from a hang.
+
+### A switching train vanished from the board the moment it left the Office
+
+**REPORTED:** Train 3 stood at the Office; dropping the loaded boxcar off the back at the Freight
+House made the train "vanish off the face of the earth," regardless of which way it moved
+afterward. The game state was never wrong — replaying the reported save
+(`docs/station-master-seed116956197-day2.json`) through the engine directly showed `tray3` fully
+intact, in the right place, with the right consist, for the rest of the game. Nothing was ever lost
+from `state.trays`.
+
+The bug was in `officeSvg` (`board-svg.ts`): `selectedTrain` — the value that decides whether a
+card draws a train's crew badge (its label, engine arrow, and cars) — was assigned only inside the
+`cell.adTracks !== null` branch, which is true for the Office card and nothing else. A train
+standing on any other card, which is every card it stands on while actually being switched, got no
+badge at all. It disappeared on the very first move off the Office, not only at the Freight House —
+that was simply the first place a player was likely to pause and look. Traced to the Roster Pass
+(37b1e5b), which rewrote `CellView.train` into `CellView.trains[]` to show every train sharing the
+Office's A/D tracks and, in doing so, nested the general consist-drawing logic inside that
+Office-only branch instead of leaving it to run for any card with a train on it.
+
+**Fixed** by hoisting the `selectedTrain` assignment out of the `adTracks !== null` guard so it
+runs for every card; the A/D roster-chip loop itself stays inside the guard, since only the Office
+has more than one A/D track to draw chips for. New test: a train parked on an ordinary facility
+card, `adTracks: null`, now has to draw its crew badge — it did not before this fix.
+
+### Unloading always took the westmost car, whichever one was picked
+
+**REPORTED:** three loaded cars stood at a Freight House; asking to unload the east (right-hand)
+car unloaded the west one instead, every time, no matter which car was actually chosen.
+
+`laborer.beginUnload` already carried the player's choice as `carIndex`, and `check()` validated
+that specific car — but the event it produced, `unloadBegan`, carried only the car's `carType`, not
+which one it was. The reducer that actually performs the swap re-derived the target itself with
+`industryTrack.cars.findIndex(c => c.loaded)`, which always answers the first loaded car in track
+order regardless of what was requested — so the player's choice was thrown away between `check` and
+the reducer, and the westmost loaded car came off every time.
+
+**Fixed** by adding `carIndex` to the `unloadBegan` event and using it directly in the reducer
+(`src/engine/apply.ts`, `case 'unloadBegan'`), instead of re-deriving a car by scanning for
+`loaded`. New test in `apply.test.ts`: three loaded cars of three different types, asking to unload
+index 2 (east) now leaves indices 0 and 1 alone and empties exactly the one requested — it did not
+before this fix.
+
+### A legal decision could render with zero buttons — the game looked hung
+
+**REPORTED:** working the Freight House mid-cycle (unloading three cars, then reloading them), the
+game "seemed to have hung up. Cannot advance." No trains were on the Division or the Limits.
+
+Replaying the reported save turned up no engine deadlock at any point — every step had a legal
+action — but the exact final state (an Extra train due to start, no tray yet being made up) exposed
+a UI bug: `newTrain.startExtra`'s action group is titled by `trainCardTitle`, which begins "Making
+up Extra X22…" — the same prefix `renderActions()` (`main.ts`) used to strip from the action list on
+the assumption it always belonged to the separate yard-chip car-placement panel. With no tray being
+filled yet, that panel (`menu.makeUp`) is `null`, so nothing else rendered the Extra's "choose where
+it starts" decision either — a legal, present, correctly-computed option with no button anywhere on
+the page. Clicking nothing did nothing, which is indistinguishable from a hang.
+
+**Fixed** by matching the exact title of the one group `menu.makeUp` actually covers
+(`g.title !== menu.makeUp?.title`) instead of a title-prefix regex, so any other group that happens
+to start "Making up …" — however it got that title — stays on screen. The existing softlock
+regression test (`never strands the player with a legal move and no way to make it`) now mirrors the
+real render filter instead of only checking the raw menu, so this class of bug fails that test
+directly; a new deterministic test constructs the exact reported scenario (a pending Extra, no
+active make-up) and asserts its group survives the filter.
+
+590 tests, 0 failures.
+
+---
+
 ## 0.4.9a — 2026-08-20
 
 Four small tweaks to the splash page (`index.html`, `splash.ts`), no engine changes.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "station-master",
-  "version": "0.4.9a",
+  "version": "0.4.9d",
   "private": true,
   "type": "module",
   "description": "Station Master — a railroad operations game",

src/engine/apply.ts

@@ -1663,7 +1663,13 @@ function execute(s: GameState, player: PlayerIndex, i: Intent): GameEvent[] {
     case 'laborer.beginUnload': {
       const f = facilityAt(s, player, i.at)!;
       return [
-        { type: 'unloadBegan', player, at: i.at, carType: f.industryTrack.cars[i.carIndex]!.type },
+        {
+          type: 'unloadBegan',
+          player,
+          at: i.at,
+          carType: f.industryTrack.cars[i.carIndex]!.type,
+          carIndex: i.carIndex,
+        },
       ];
     }
 
@@ -2206,7 +2212,17 @@ export function reduce(s: GameState, e: GameEvent): void {
 
     case 'unloadBegan': {
       const f = facilityAt(s, e.player, e.at)!;
-      const ci = f.industryTrack.cars.findIndex((c) => c.loaded);
+      /**
+       * THE CAR THE PLAYER PICKED, not merely "a loaded one".
+       *
+       * REPORTED: with several loaded cars spotted on one industry track, unloading always took the
+       * WESTMOST car regardless of which one was chosen. This used to re-derive the target with
+       * `industryTrack.cars.findIndex(c => c.loaded)`, which returns the same answer — the first
+       * loaded car in track order — no matter which `carIndex` the intent actually named; `check`
+       * had already validated that specific car, and the choice was thrown away between there and
+       * here. `e.carIndex` is exactly what `laborer.beginUnload`'s reducer read off the intent.
+       */
+      const ci = e.carIndex;
       if (ci >= 0) {
         /**
          * §9.3 — the replacement empty comes out of the Division Yard. Conjuring it here is what

src/engine/events.ts

@@ -167,7 +167,11 @@ export type GameEvent =
   | { type: 'loadAdvanced'; player: PlayerIndex; at: GridCoord; fromBox: number; toBox: number }
   | { type: 'unloadCompleted'; player: PlayerIndex; at: GridCoord; carType: CarType }
   | { type: 'loadCompleted'; player: PlayerIndex; at: GridCoord; carType: CarType }
-  | { type: 'unloadBegan'; player: PlayerIndex; at: GridCoord; carType: CarType }
+  /**
+   * `carIndex` carries the SPECIFIC car the player picked off the industry track — see the comment
+   * on `laborer.beginUnload` in `apply.ts` for why the reducer must not re-derive it.
+   */
+  | { type: 'unloadBegan'; player: PlayerIndex; at: GridCoord; carType: CarType; carIndex: number }
   // -- consequences
   | { type: 'revenueChanged'; player: PlayerIndex; delta: number; total: number; reason: string }
   | { type: 'phaseEnded'; player: PlayerIndex; phase: string };

src/sim/board-svg.ts

@@ -568,13 +568,21 @@ export function officeSvg(
      * Selected train's chip is lit the same amber the crew strip and action buttons already use,
      * and it is the one whose consist is drawn at the rail below. Every occupied chip carries
      * `data-crew`, so the play page can wire a click to switch which train that is.
+     *
+     * COMPUTED FOR EVERY CARD, NOT JUST THE OFFICE. This used to sit inside the `adTracks !== null`
+     * branch below, so it was only ever assigned on the Office card — a train standing anywhere else
+     * in the district (which is everywhere it stands while actually being switched) got no chip at
+     * all: no label, no engine arrow, and no cars drawn, though the game state never lost it. REPORTED:
+     * dropping a car at the Freight House made "the train vanish off the face of the earth" — it had
+     * simply left the one square this code drew a crew on. The Office is the only square that can hold
+     * more than one train, so `cell.trains[0]` is exactly right everywhere else too.
      */
-    let selectedTrain: CellView['trains'][number] | null = null;
+    const selectedTrain: CellView['trains'][number] | null =
+      cell.trains.find((t) => t.trayId === selectedTrayId) ?? cell.trains[0] ?? null;
     if (cell.adTracks !== null) {
       const adTracks = cell.adTracks;
       const gaps = Math.max(0, adTracks - 1);
       const chipW = Math.min(52, (W - 12 - 4 * gaps) / adTracks);
-      selectedTrain = cell.trains.find((t) => t.trayId === selectedTrayId) ?? cell.trains[0] ?? null;
       for (let i = 0; i < adTracks; i++) {
         const train = cell.trains[i] ?? null;
         const cx = 6 + i * (chipW + 4);

src/web/main.ts

@@ -832,9 +832,19 @@ function renderActions(
    * Everything about a card in hand now lives on the card, and everything about making up a train
    * lives on the yard chip. What remains is the rest of the turn: the Local Operations choice,
    * drawing, switching moves, the Freight Agent, and finishing.
+   *
+   * EXCLUDE BY TITLE, NOT BY PREFIX. This used to be `!/^Making up /.test(g.title)`, on the
+   * assumption only the yard-chip panel's own group is ever titled that way. It is not: "choose
+   * where Extra X22 starts" is titled by `trainCardTitle`, which also begins "Making up Extra
+   * X22…", so the regex swallowed it too — and with no tray yet being filled, `menu.makeUp` is
+   * null, so nothing rendered it anywhere else. REPORTED as the game hanging with the Freight
+   * House mid-cycle: an Extra came due, the action panel had a legal decision and zero buttons,
+   * and nothing short of restarting looked like it would ever move again. Matching the exact
+   * title of the ONE group `menu.makeUp` actually covers leaves every other "Making up …" group,
+   * however it is titled, on screen where a player can act on it.
    */
   html += menu.direct
-    .filter((g) => !/^(Play|Discard) a card from my hand$/.test(g.title) && !/^Making up /.test(g.title))
+    .filter((g) => !/^(Play|Discard) a card from my hand$/.test(g.title) && g.title !== menu.makeUp?.title)
     .map(
       (g) =>
         `<div class="grp"><h3>${esc(g.title)}</h3>` +

test/apply.test.ts

@@ -685,6 +685,61 @@ describe('Load/Unload: the four-action freight pipeline (§9.3)', () => {
     assert.equal(check(s, 0, { type: 'laborer.startLoad', at: coord }), 'NO_EMPTY_CAR_SPOTTED');
   });
 
+  it('unloads the car the player actually picked, not always the westmost one', () => {
+    // REPORTED FROM PLAY: three loaded cars stood at a Freight House; asking to unload the EAST
+    // (index 2) car unloaded the WEST one instead, every time, regardless of which car was picked.
+    // The reducer for `unloadBegan` used to re-derive the target with
+    // `industryTrack.cars.findIndex(c => c.loaded)`, which always answers the first loaded car in
+    // track order no matter which `carIndex` the intent actually named.
+    const s = game();
+    const coord = at(-1, 0);
+    addCard(s, coord, {
+      geometry: { kind: 'facility', facility: 'freightHouse' },
+      baseOperationalRail: true,
+      standing: [],
+      standingWest: 0,
+      facility: {
+        kind: 'freight',
+        subtype: 'freightHouse',
+        allows: { outbound: true, inbound: true },
+        outboundBox: [],
+        inboundBox: [],
+        capacity: { outbound: 1, inbound: 1 },
+        menAtWork: [null, null, null],
+        industryTrack: {
+          cars: [
+            { type: 'boxcar', loaded: true },
+            { type: 'hopper', loaded: true },
+            { type: 'tank', loaded: true },
+          ],
+        },
+        laborers: 3,
+        porters: 0,
+        usedThisStage: { laborers: 0, porters: 0 },
+      },
+      modifiers: [],
+      enhancements: [],
+    });
+    s.clock.phase = 'loadUnload';
+    // An empty replacement of every type standing on the track, so `check` never refuses for a
+    // reason unrelated to what this test is about.
+    s.yards.divisionYard.push(
+      { type: 'boxcar', loaded: false },
+      { type: 'hopper', loaded: false },
+      { type: 'tank', loaded: false },
+    );
+
+    const r = applyIntent(s, 0, { type: 'laborer.beginUnload', at: coord, carIndex: 2 });
+    assert.ok(r.ok, 'unloading the east (index 2) car should be legal');
+    const f = areaOf(s, 0).grid.get(coordKey(coord))!.facility!;
+    assert.equal(f.industryTrack.cars[0]!.type, 'boxcar', 'the west car must be untouched');
+    assert.equal(f.industryTrack.cars[0]!.loaded, true, 'the west car must still be loaded');
+    assert.equal(f.industryTrack.cars[1]!.type, 'hopper', 'the middle car must be untouched');
+    assert.equal(f.industryTrack.cars[1]!.loaded, true, 'the middle car must still be loaded');
+    assert.equal(f.industryTrack.cars[2]!.type, 'tank', 'the east car — the one picked — must still be there');
+    assert.equal(f.industryTrack.cars[2]!.loaded, false, 'the east car is the one that should be emptied');
+  });
+
   it('takes four Laborer actions in total for one point', () => {
     // The asymmetry the whole economy is calibrated against (card-reference.md §2).
     const s = game();

test/replay.test.ts

@@ -58,7 +58,7 @@ const SAMPLES: GameEvent[] = [
   { type: 'loadAdvanced', player: 0, at: { row: 1, col: 0 }, fromBox: 0, toBox: 1 },
   { type: 'unloadCompleted', player: 0, at: { row: 1, col: 0 }, carType: 'hopper' },
   { type: 'loadCompleted', player: 0, at: { row: 1, col: 0 }, carType: 'hopper' },
-  { type: 'unloadBegan', player: 0, at: { row: 1, col: 0 }, carType: 'hopper' },
+  { type: 'unloadBegan', player: 0, at: { row: 1, col: 0 }, carType: 'hopper', carIndex: 0 },
   { type: 'revenueChanged', player: 0, delta: 1, total: 3, reason: 'freightLoad' },
   { type: 'phaseEnded', player: 0, phase: 'localOps' },
 ];

test/web.test.ts

@@ -1787,7 +1787,19 @@ describe('the static build', () => {
     // click-through happens to visit.
     const reachable = (menu: ReturnType<typeof actionMenu>): Set<number> => {
       const out = new Set<number>();
-      for (const g of menu.direct) for (const a of g.actions) out.add(a.index);
+      /**
+       * THE SAME EXCLUSION `renderActions()` (main.ts) APPLIES, not the raw menu.
+       *
+       * `menu.direct` alone is what the ENGINE offers; `renderActions()` then drops any group whose
+       * title matches the one `menu.makeUp` already covers, so a group counted here but filtered
+       * there is exactly the gap that stranded a pending Extra with `menu.makeUp` null and its own
+       * "Making up Extra X22…" title caught by the OLD broader regex this once was. Mirroring the
+       * real filter is what makes this test the one that would have caught that.
+       */
+      const onScreen = menu.direct.filter(
+        (g) => !/^(Play|Discard) a card from my hand$/.test(g.title) && g.title !== menu.makeUp?.title,
+      );
+      for (const g of onScreen) for (const a of g.actions) out.add(a.index);
       for (const g of menu.placeable) for (const it of g.items) for (const sp of it.spots) out.add(sp.index);
       for (const h of menu.hand) {
         if (h.playNow !== null) out.add(h.playNow);
@@ -1817,6 +1829,37 @@ describe('the static build', () => {
     }
   });
 
+  it('offers "where does this Extra start" on screen, not just in the menu', () => {
+    // REPORTED: the game "hung" mid-Freight-House-work with nothing to click. `newTrain.startExtra`
+    // was legal and present in `menu.direct` — the engine was never stuck — but its group is titled
+    // by `trainCardTitle`, which begins "Making up Extra X22…" exactly like the yard-chip panel's
+    // OWN group. `renderActions()` used to drop every group titled that way, on the assumption only
+    // the yard-chip panel used the prefix; with no tray yet being filled (`menu.makeUp` is null,
+    // since the Extra has not chosen where it starts yet), that group was the only thing offered and
+    // it vanished from the page — a legal decision with zero buttons.
+    const game = newGame(430);
+    game.state.pendingExtras.push(22); // Extra X22 "Pee-Dee" — one caboose, per-diem.
+    game.state.clock.phase = 'newTrain';
+    game.state.clock.currentActor = 0;
+    assert.equal(currentActor(game), 0, 'a decision should be waiting');
+
+    const menu = actionMenu(game);
+    assert.equal(menu.makeUp, null, 'no tray is being filled — the Extra has not started yet');
+    const extraGroup = menu.direct.find((g) => g.actions.some((a) => menu.options[a.index]?.type === 'newTrain.startExtra'));
+    assert.ok(extraGroup, 'newTrain.startExtra should appear in some menu.direct group');
+    assert.match(extraGroup!.title, /^Making up /, 'this is exactly the title shape that used to collide');
+
+    // The actual filter `renderActions()` applies (main.ts) — reproduced here for the reason given
+    // on `reachable()` above: there is no DOM harness in this suite to call the real renderer.
+    const onScreen = menu.direct.filter(
+      (g) => !/^(Play|Discard) a card from my hand$/.test(g.title) && g.title !== menu.makeUp?.title,
+    );
+    assert.ok(
+      onScreen.includes(extraGroup!),
+      'the Extra\'s "choose where it starts" group was filtered out along with the yard-chip panel',
+    );
+  });
+
   it('renders every part of the menu it is given', () => {
     // THE CHECK THAT WOULD HAVE CAUGHT THE SOFTLOCK ABOVE. The option was in the menu all along —
     // `makeUp.pass` was computed correctly and simply never rendered, so the invariant on the menu
@@ -2054,6 +2097,27 @@ describe('the static build', () => {
     }
   });
 
+  it('draws the crew chip on a train standing away from the Office', () => {
+    // REPORTED: dropping a loaded boxcar off the back of Train 3 at the Freight House made "the
+    // train vanish off the face of the earth". The game state was never wrong — `selectedTrain` was
+    // only ever assigned inside the `cell.adTracks !== null` branch, so a train standing on any card
+    // OTHER than the Office (which is every card it stands on while actually being switched) got no
+    // badge at all: no label, no engine arrow, no cars. This is the Freight House from that report —
+    // an ordinary facility card, `adTracks: null`, one train parked on it mid-switch.
+    const cell = {
+      row: 1, col: 0, kind: 'facility', label: 'Freight House', running: false,
+      enhancements: [], enhancementsWhat: [], adTracks: null,
+      trains: [{
+        trayId: 'tray3', label: 'T3', cars: ['empty boxcar'], engineAt: 0, facing: 'w' as const,
+        what: 'Train 3 "Express"',
+      }],
+      cars: [], standingWest: 0, facility: null, links: ['ew'], what: '',
+    };
+    const svg = officeSvg([cell as never], 0);
+    assert.match(svg, /class="bs-crew"/, 'the crew badge is not drawn off the Office square');
+    assert.match(svg, />T3</, 'the train\'s own label is missing from the board');
+  });
+
   it('draws a bare cut left-aligned, whatever the card\'s stored standingWest says', () => {
     // "Settled questions" in docs/plans/switching-paths.md — the split only ever predicts something
     // while a train stands on the card, and an earlier draft of the plan had this backwards. A stale