Complete REGULAR_BATTLE immediately, fix stale saveslot tests

REGULAR_BATTLE previously never completed on its own, hanging any
cutscene that reached it - START_BATTLE already waits out the whole
encounter and returns to the overworld before this item ever runs, so
it's now a completes-immediately hook point for future regular-battle-
specific follow-up.

Also updates test_saveslot.c for the mapName/partyMembers schema
additions: the round-trip test now writes a valid map name for its
in-use slot, "missingFieldsUseDefaults" is replaced with a test for the
blank-slot short-circuit it was actually hitting, and a new regression
test locks in that an in-use slot with no map name is treated as corrupt.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/dusk/rpg/cutscene/item/battle/cutsceneregularbattle.c

@@ -11,5 +11,5 @@ bool_t cutsceneRegularBattleUpdate(
   const cutsceneitem_t *item,
   cutsceneitemdata_t *data
 ) {
-  return false;
+  return true;
 }

src/dusk/rpg/cutscene/item/battle/cutsceneregularbattle.h

@@ -9,12 +9,15 @@
 #include "rpg/cutscene/item/cutsceneitembase.h"
 
 /**
- * Updates a regular-battle step. Currently a placeholder - behaves exactly
- * like IDLE (see cutsceneidle.h) and never completes on its own.
+ * Updates a regular-battle step. By the time this item runs, the preceding
+ * START_BATTLE item has already waited out the whole encounter, synced
+ * party HP/MP, and returned to the overworld scene - so this is currently
+ * just a completes-immediately hook point for whatever regular-battle-
+ * specific follow-up (loot, post-battle dialogue, etc.) gets added later.
  *
  * @param item The cutscene item.
  * @param data Runtime data storage.
- * @returns false always.
+ * @returns true always.
  */
 bool_t cutsceneRegularBattleUpdate(
   const cutsceneitem_t *item,

test/save/test_saveslot.c

@@ -143,6 +143,12 @@ static void test_saveSlotReadJSON_roundTrip(void **state) {
   written.version = 7;// deliberately non-default, not part of the JSON schema
   stringCopy(written.cachedData.name, "Hero", sizeof(written.cachedData.name));
   written.cachedData.playerLevel = 42;
+  // An in-use slot (non-empty name) requires a non-empty map name too -
+  // see saveSlotNewGame/requireStrMin("mapName", 1) in saveSlotVer1ReadJSON.
+  stringCopy(
+    written.cachedData.mapName, "overworld",
+    sizeof(written.cachedData.mapName)
+  );
 
   char_t *json;
   size_t len;
@@ -157,6 +163,7 @@ static void test_saveSlotReadJSON_roundTrip(void **state) {
 
   assert_true(stringEquals(read.cachedData.name, "Hero"));
   assert_int_equal(read.cachedData.playerLevel, 42);
+  assert_true(stringEquals(read.cachedData.mapName, "overworld"));
   assert_true(read.cachedData.time.time == written.cachedData.time.time);
 
   // version/dataType are struct-only bookkeeping, never serialized - the
@@ -167,21 +174,40 @@ static void test_saveSlotReadJSON_roundTrip(void **state) {
   free(json);
 }
 
-static void test_saveSlotReadJSON_missingFieldsUseDefaults(void **state) {
+static void test_saveSlotReadJSON_blankSlot_shortCircuits(void **state) {
   saveslot_t slot;
   saveSlotInit(&slot);
   stringCopy(slot.cachedData.name, "sentinel", sizeof(slot.cachedData.name));
   slot.cachedData.playerLevel = 999;
 
-  errorret_t ret = slotFromJSON(
-    &slot,
-    "{\"version\":1,"
-    "\"time\":{\"time\":1.0,\"timeZone\":0.0,\"offsetTime\":0.0}}"
-  );
+  // No "name" key (or an empty one) means a blank/never-used slot (see
+  // saveSlotInUse) - the reader returns right after reading that, without
+  // needing or validating time/mapName/partyMembers/partyOrder at all, so
+  // this succeeds despite omitting fields that would otherwise be required.
+  errorret_t ret = slotFromJSON(&slot, "{\"version\":1}");
   assert_true(errorIsOk(ret));
 
   assert_int_equal(slot.cachedData.name[0], '\0');
-  assert_int_equal(slot.cachedData.playerLevel, 1);
+  assert_int_equal(slot.cachedData.mapName[0], '\0');
+  // Not readInt32's own default of 1 - the early return happens before
+  // playerLevel is ever read, leaving the zero-init saveSlotCurrentReadJSON
+  // seeds ver1 with (see the memoryZero in saveSlotCurrentReadJSON).
+  assert_int_equal(slot.cachedData.playerLevel, 0);
+}
+
+static void test_saveSlotReadJSON_inUseMissingMapName_errors(void **state) {
+  saveslot_t slot;
+  saveSlotInit(&slot);
+
+  // "name" is present (in use) but "mapName" is missing - a real save
+  // (via saveSlotNewGame) always has both, so this is corrupt.
+  errorret_t ret = slotFromJSON(
+    &slot,
+    "{\"version\":1,\"name\":\"Hero\","
+    "\"time\":{\"time\":1.0,\"timeZone\":0.0,\"offsetTime\":0.0}}"
+  );
+  assert_true(errorIsNotOk(ret));
+  errorCatch(ret);
 }
 
 static void test_saveSlotReadJSON_missingTimeKey_errors(void **state) {
@@ -265,7 +291,8 @@ int main(void) {
 
     cmocka_unit_test(test_saveSlotReadJSON_nullAsserts),
     cmocka_unit_test(test_saveSlotReadJSON_roundTrip),
-    cmocka_unit_test(test_saveSlotReadJSON_missingFieldsUseDefaults),
+    cmocka_unit_test(test_saveSlotReadJSON_blankSlot_shortCircuits),
+    cmocka_unit_test(test_saveSlotReadJSON_inUseMissingMapName_errors),
     cmocka_unit_test(test_saveSlotReadJSON_missingTimeKey_errors),
     cmocka_unit_test(test_saveSlotReadJSON_nameTooLong_errors),
     cmocka_unit_test(test_saveSlotReadJSON_nonObjectRoot_errors),