Speicherstand mit Prüfsumme und Prüfung beim Laden

Snapshots tragen jetzt eine Prüfsumme (Format 2). Beim Wiederherstellen
werden Zustände abgelehnt, die die Regeln nie erzeugen: zu große Takte,
mehr als vier Spieler online, doppelte Schlüssel, unmögliche
Wartezeiten. World::load ersetzt den öffentlichen Aufruf von
set_all_offline. Die festgeschriebenen Werte sind bewusst angepasst und
um einen Offline-Spieler und das Kartenformat ergänzt.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

core/tests/golden.rs

@@ -1,15 +1,16 @@
 //! Pinned values for everything that must not change unnoticed.
 //!
-//! Every other test compares two computations inside the same build, so a
+//! Most other tests compare two computations inside the same build, so a
 //! change that affects both sides alike stays green. This file compares
 //! against values recorded once. If one of them fails, rules or encodings
 //! changed, on purpose or by accident. If saves or recordings are affected,
 //! raise the version constant named in the failure message, then update the
 //! value here deliberately.
 
+use grovewright_core::codec::Writer;
 use grovewright_core::command::Command;
 use grovewright_core::hash::fnv1a64;
-use grovewright_core::map::Pos;
+use grovewright_core::map::{Map, Pos, Terrain, Tile};
 use grovewright_core::mapgen::outcrop_origin;
 use grovewright_core::player::PlayerId;
 use grovewright_core::replay::Recording;
@@ -99,13 +100,55 @@ fn frozen_script(world: &World) -> Vec<Vec<Command>> {
     ticks
 }
 
-/// Covers the map generator, the map encoding (terrain numbers, byte order of
-/// width and height) and the snapshot header.
+/// The commands of a second session of 30 ticks that ends with one player
+/// offline, so that the encoding of offline players is pinned as well.
+///
+/// Never change or extend this script either.
+fn frozen_offline_script(world: &World) -> Vec<Vec<Command>> {
+    let origin = outcrop_origin(world.map());
+    let scripted = [
+        (
+            0,
+            Command::Join {
+                key: [7; 16],
+                name: "Linus".to_owned(),
+            },
+        ),
+        (
+            1,
+            Command::Join {
+                key: [8; 16],
+                name: "Margaret".to_owned(),
+            },
+        ),
+        (
+            3,
+            Command::Dig {
+                player: PlayerId(1),
+                pos: origin,
+            },
+        ),
+        (
+            10,
+            Command::Leave {
+                player: PlayerId(0),
+            },
+        ),
+    ];
+    let mut ticks = vec![Vec::new(); 30];
+    for (tick, command) in scripted {
+        ticks[tick].push(command);
+    }
+    ticks
+}
+
+/// Covers the map generator, the map encoding and the snapshot header and
+/// checksum.
 #[test]
 fn the_starting_snapshot_is_unchanged() {
     let actual = fnv1a64(&World::new(SEED).to_snapshot());
     assert_eq!(
-        actual, 0x1b78_d996_1586_fbf1,
+        actual, 0x6812_937b_f2b2_19ae,
         "the starting world or the snapshot format changed; if saves are \
          affected, raise SNAPSHOT_VERSION in core/src/snapshot.rs; then \
          update this value"
@@ -129,6 +172,22 @@ fn the_frozen_session_ends_in_the_same_state() {
     );
 }
 
+/// Covers the encoding of a player who is offline.
+#[test]
+fn the_frozen_offline_session_ends_in_the_same_state() {
+    let mut world = World::new(SEED);
+    for commands in frozen_offline_script(&world) {
+        world.step(&commands);
+    }
+    assert_eq!(
+        world.state_hash(),
+        0x904f_10e1_7c52_8be4,
+        "the rules or the snapshot format changed; old recordings no longer \
+         verify; if saves are affected, raise SNAPSHOT_VERSION in \
+         core/src/snapshot.rs; then update this value"
+    );
+}
+
 /// Covers the recording header and layout and the wire format of commands.
 #[test]
 fn the_recording_format_is_unchanged() {
@@ -140,8 +199,40 @@ fn the_recording_format_is_unchanged() {
     }
     assert_eq!(
         fnv1a64(&recording.to_bytes(&world)),
-        0x2312_5a7d_d8ef_5ae0,
-        "the recording or command format changed; raise RECORDING_VERSION in \
-         core/src/replay.rs; then update this value"
+        0x1c24_8cc7_6bc8_846a,
+        "the recording or command format changed; if other tests in this \
+         file fail as well, deal with those first, because a recording \
+         contains a snapshot and an end state; otherwise raise \
+         RECORDING_VERSION in core/src/replay.rs; then update this value"
+    );
+}
+
+/// Covers the byte layout of a map: width before height, little endian,
+/// terrain numbers and damage. The map is not square, so a swap of width
+/// and height shows.
+#[test]
+fn the_map_encoding_is_unchanged() {
+    let mut map = Map::filled(3, 2, Terrain::Ground);
+    map.set(Pos::new(1, 0), Tile::new(Terrain::Bedrock));
+    map.set(Pos::new(0, 1), Tile::new(Terrain::HardRock));
+    map.set(
+        Pos::new(2, 1),
+        Tile {
+            terrain: Terrain::SoftRock,
+            damage: 1,
+        },
+    );
+    let mut w = Writer::new();
+    map.encode(&mut w);
+    assert_eq!(
+        w.into_bytes(),
+        vec![
+            3, 0, 0, 0, // width
+            2, 0, 0, 0, // height
+            0, 0, 3, 0, 0, 0, // row 0: ground, bedrock, ground
+            2, 0, 0, 0, 1, 1, // row 1: hard rock, ground, soft rock hit once
+        ],
+        "the map encoding changed; raise SNAPSHOT_VERSION in \
+         core/src/snapshot.rs; then update these bytes"
     );
 }